1. |
- Fellman, Vineta, et al.
(author)
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One-year survival of extremely preterm infants after active perinatal care in Sweden.
- 2009
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In: JAMA : the journal of the American Medical Association. - : American Medical Association (AMA). - 1538-3598 .- 0098-7484. ; 301:21, s. 2225-33
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Journal article (peer-reviewed)abstract
- Up-to-date information on infant survival after extremely preterm birth is needed for assessing perinatal care services, clinical guidelines, and parental counseling.
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2. |
- Finnström, Orvar, 1938-, et al.
(author)
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IVF i Sverige - Fortsatt uppföljning av barn och mödrar
- 2006
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In: Läkartidningen. - 0023-7205 .- 1652-7518. ; 103:32-33, s. 2301-2305
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Journal article (peer-reviewed)abstract
- This paper summarises six recently published studies which evaluate Swedish in vitro fertilization from 1982 to 2003 and is a register study, based on national registers linked through personal identification numbers. Data were available for all 12186 mothers and their 16280 children. Comparisons were made with the total delivering population. The number of children born after IVF increases steadily and amounts to 3% presently. The number of twins has decreased considerably. Some increased risks persist after IVF, a slightly higher perinatal death rate and an increased risk for congenital malformations. There were no differences between conventional IVF and ICSI. The risk for cancer was not increased with one possible exception, histiocytosis. Morbidity during childhood measured as hospital admissions, was increased due to more preterm births and multiple births in the IVF group. IVF mothers were older and smoked less than other mothers. Their medical drug use differed from that of other pregnant women. In general they had a decreased cancer risk, but probably an increased risk for ovarian cancer. Maternal mortality was not increased. Several obstetric complications were more common in IVF mothers: ovarial torsion, preeclampsia, premature rupture of membranes, bleeding at delivery and placental abruption. The deliveries were more often induced, and the frequency of caesarean section was increased.
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3. |
- Finnström, Orvar, et al.
(author)
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Maternal and child outcome after in-vitro fertilization-a review of 25 years population based data from Sweden.
- 2011
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In: Acta Obstetricia et Gynecologica Scandinavica. - : Wiley. - 1600-0412 .- 0001-6349. ; 90:5, s. 494-500
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Journal article (peer-reviewed)abstract
- Objective. To summarize data on deliveries after IVF performed in Sweden up to 2006. Design. Cohort study of women and children, conceived after IVF with comparisons of deliveries after IVF before and after April 1, 2001. Setting. Study based on Swedish health registers. Population. Births registered in the Swedish Medical Birth Register with information on IVF from all IVF clinics in Sweden. Methods. Results from the second study period are summarized and outcomes between the two periods are compared. Long term follow-up is based on data from both periods. Main outcome measures. Maternal and perinatal outcomes, long term sequels. Results. Some maternal pregnancy complications decreased in rate, notably preeclampsia and PROM. The rate of multiple births and preterm births decreased dramatically with a better neonatal outcome, including neonatal mortality. No difference in outcome existed between IVF and ICSI or between the use of fresh and cryopreserved embryos, but children born after blastocyst transfer had a slightly higher risk for preterm birth and congenital malformations than children born after cleavage stage transfer. An increased risk for cerebral palsy, possibly for attention deficit and hyperactivity disorder, for impaired visual acuity, and for childhood cancer was noted but these outcomes were rare also after IVF. An increased risk for asthma was demonstrated. No effect on maternal cancer risk was seen. Conclusions. A marked decrease in multiple births was the main reason for better pregnancy and neonatal outcome and may also have a beneficial effect on long-term results, notably cerebral palsy.
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4. |
- Finnström, Orvar, 1938-, et al.
(author)
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Size of delivery unit and neonatal outcome in Sweden. A catchment area analysis
- 2006
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In: Acta Obstetricia et Gynecologica Scandinavica. - : Wiley. - 0001-6349 .- 1600-0412. ; 85:1, s. 63-67
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Journal article (peer-reviewed)abstract
- Background. Quality of perinatal care was evaluated in relation to size of delivery unit and size of catchment area for deliveries. Methods. Neonatal outcome, measured as neonatal mortality, low Apgar scores at 5 min, and the occurrence of respiratory disorders and cerebral palsy was analyzed during a 15-year period from 1985 to 1999 inclusive. Figures were derived from the Swedish Medical Birth Registry and the Hospital Discharge Registry. Odds ratios were estimated for the different outcomes in relation to size of delivery unit (actual and estimated number of births) and the provision of a pediatric department at the hospital. Seven possible confounders were considered: year of birth, maternal age, parity, smoking during pregnancy, gestational age, parental cohabitation, and maternal body mass index. Results. Neonatal mortality was significantly higher for infants in families living within the catchment area of the smallest units without a pediatric department. Small differences in the occurrence of respiratory disturbances and Apgar scores are probably due to diagnostic differences. There were no differences in the incidence of cerebral palsy. Neonatal mortality continued to decrease during the observation period. Conclusions. Differences were minor, pointing to a fairly homogeneous quality of perinatal care and an efficient referral system for risk pregnancies. Mortality continues to decrease in spite of a reduction in the number of units caring for deliveries. © 2006 Taylor & Francis.
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5. |
- Frid, Christina, et al.
(author)
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Maternal and neonatal factors and mortality in children with Down syndrome born in 1973-1980 and 1995-1998
- 2004
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In: Acta Paediatrica. - : Wiley. - 0803-5253 .- 1651-2227. ; 93:1, s. 106-112
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Journal article (peer-reviewed)abstract
- AIMS:To investigate maternal and neonatal factors in Down syndrome (DS) at birth, the impact of a congenital heart defect (CHD) on these factors and changes over time.METHODS:Medical data of children with DS born in northern Sweden in the periods 1973-1980 (n = 219) and 1995-1998 (n = 88) obtained from the Swedish Medical Birth Register were compared. A comparison with the general population on a group level was also made.RESULTS:The main finding was a reduction in infant mortality in DS, from 14.2% to 2.3% in 1995-1998 (p < 0.001), but this was still significantly higher than in the general population. The rate of Caesarean sections increased over time (from 14.5% to 27.3%, p < 0.05) even after adjustment for increased maternal age. No change over time was detected in the following rates: premature birth (gestational age < or = 36) (25%); asphyxia (5-min Apgar score < or = 6) (8%); low birthweight (< 2500 g) (14%); or small for gestational age (SGA) (14%); all rates were significantly higher than those of the general population. A CHD did not seem to influence the rates of these factors in a logistic regression model.CONCLUSION:Infant mortality decreased substantially over time in the DS group, whereas there was no reduction in the rate of asphyxia, SGA, low birthweight or prematurity. The presence of a CHD did not influence any of the neonatal factors studied.
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6. |
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7. |
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8. |
- Källén, Bengt, et al.
(author)
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Antidepressant use during pregnancy: comparison of data obtained from a prescription register and from antenatal care records.
- 2011
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In: European Journal of Clinical Pharmacology. - : Springer Science and Business Media LLC. - 1432-1041 .- 0031-6970. ; 67, s. 839-845
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Journal article (peer-reviewed)abstract
- PURPOSE: To compare interview data on drug use during pregnancy with data identified from a register of prescriptions. MATERIALS: We compared information from the Swedish Prescribed Drug Register with the Swedish Medical Birth Register on antidepressant use. In order to evaluate the clinical significance of the difference in ascertainment with the two methods, the rate of preterm births among singletons and of neonatal symptoms were studied. RESULTS: During the year before the last menstrual period, 1.5% of the women filled prescriptions for antidepressants each month. Already before the pregnancy was known, the rate of filled prescriptions decreased and reached 0.5% towards the end of the pregnancy. Twenty-two percent of first-trimester use of antidepressants was unidentified using interview data and prescriptions during the 2nd and 3rd pregnancy months covered only 55% of actual use. When women who filled prescriptions 1 or 3 months before the last menstrual period were included, 17 and 43% respectively of women were included who probably did not use the drugs in the first trimester. Prescriptions gave a more complete ascertainment of drug use after the first trimester than data from antenatal care, which seemed to overestimate drug use. CONCLUSIONS: Interview data seem to give the most valid results on early use. When interview data are not available, prescription data could be used, but should not include prescriptions given earlier than 1 month before the last menstrual period. Studies of drug use later in pregnancy are best based on prescription data in the absence of interview data.
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9. |
- Källén, Bengt, et al.
(author)
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Association between preterm birth and intrauterine growth retardation and child asthma
- 2013
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In: European Respiratory Journal. - : European Respiratory Society: ERJ. - 0903-1936 .- 1399-3003. ; 41:3, s. 671-676
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Journal article (peer-reviewed)abstract
- An association between preterm birth and an increased risk of childhood asthma has been demonstrated, but the importance of intrauterine growth retardation on asthma risk is unclear. less thanbrgreater than less thanbrgreater thanUsing data from Swedish health registers, infant characteristics and childhood asthma were studied. Analyses were made using Mantel-Haenszel methodology with adjustment for year of birth, maternal age, parity, smoking in early pregnancy and maternal body mass index. Preterm birth, birth weight and birth weight for gestational week were analysed and childhood asthma was evaluated from prescriptions of anti-asthmatic drugs. Neonatal respiratory problems and treatment for them were studied as mediating factors. less thanbrgreater than less thanbrgreater thanBoth short gestational duration and intrauterine growth retardation appeared to be risk factors and seemed to act separately. The largest effect was seen from short gestational duration. Use of mechanical ventilation in the newborn period and bronchopulmonary dysplasia were strong risk factors. A moderately increased risk was also seen in infants born large for gestational age. less thanbrgreater than less thanbrgreater thanWe conclude that preterm birth is a stronger risk factor for childhood asthma than intrauterine growth disturbances; however, the latter also affects the risk, and is also seen in infants born at term.
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10. |
- Källén, Bengt, et al.
(author)
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Asthma in Swedish children conceived by in vitro fertilisation
- 2013
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In: Archives of Disease in Childhood. - : BMJ Publishing Group. - 0003-9888 .- 1468-2044. ; 98:2, s. 92-96
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Journal article (peer-reviewed)abstract
- Objectives To investigate a proposed association between in vitro fertilisation (IVF) and child asthma. less thanbrgreater than less thanbrgreater thanDesign The risk for asthma after IVF was estimated as ORs using Mantel-Haenszel analysis. less thanbrgreater than less thanbrgreater thanSetting The Swedish Medical Birth Register. less thanbrgreater than less thanbrgreater thanPatients Of the 2 628 728 children born in 1982-2007 and surviving the perinatal period, 31 918 were conceived by IVF. Presence of asthma was defined as at least five prescriptions of antiasthmatic drugs during the period 1 July 2005-31 December 2009 according to the Swedish Prescribed Drug Register (115 767 children, 2323 of whom were born after IVF). less thanbrgreater than less thanbrgreater thanResults A significantly increased risk for asthma, albeit small, was found in children conceived by IVF (aOR 1.28, 95% CI 1.23 to 1.34), increasing the absolute risk from 4.4% to 5.6%. The risk increase for asthma was the same in boys and girls, in singletons and twins, and after caesarean section and vaginal delivery. The risk was higher for preterm than term singletons. For children with a low Apgar score, respiratory diagnoses, mechanical ventilation, continuous positive airway pressure or neonatal sepsis, the effect of IVF on asthma risk was low and statistically non-significant. Adjustment for length of involuntary childlessness eliminated the effect, and removal of infants whose mothers had used antiasthmatics in early pregnancy reduced the risk. less thanbrgreater than less thanbrgreater thanConclusions This study verifies an association between IVF and asthma in children. This can be partly explained by neonatal morbidity and by maternal asthma acting as mediators, but the main risk factor is parental subfertility. The mechanism for this is unclear.
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11. |
- Källén, Bengt, et al.
(author)
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Blastocyst versus cleavage stage transfer in in vitro fertilization: differences in neonatal outcome?
- 2010
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In: FERTILITY AND STERILITY. - : Elsevier Science B.V., Amsterdam.. - 0015-0282 .- 1556-5653. ; 94:5, s. 1680-1683
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Journal article (peer-reviewed)abstract
- Objective: To compare neonatal outcome of blastocyst and cleavage stage embryo transfers after IVF. Design: Register study. Setting: Births recorded in the Swedish Medical Birth Register after IVF performed, 2002-2006. Patient(s): Treatments reported from all Swedish IVF clinics. Intervention(s): None. Main Outcome Measure(s): Some neonatal characteristics were compared in 1,311 infants born after blastocyst-stage transfer and 12,562 infants born after cleavage-stage transfer. Comparisons were also made with all births, 2002-2007 (n = 598,687). Result(s): After adjusting for year of birth, maternal age, parity, smoking habits, and body mass index, the risk of preterm birth among singletons was significantly greater after blastocyst-stage transfer than after cleavage-stage transfer. The risk of congenital malformations was also significantly higher. When the analysis was restricted to clinics where blastocyst transfers were made, the risk estimates increased for preterm birth, low birth weight, low APGAR score, and respiratory diagnoses, but did not change for congenital malformations. Conclusion(s): The results indicate a small increase in risk associated with blastocyst transfer, perhaps owing to the longer period of in vitro culture. There is a possibility that this effect is due, at least in part, to a selection of women for blastocyst transfers. Further studies are needed either to verify or to refute the found associations.
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12. |
- Källén, Bengt, et al.
(author)
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Cancer Risk in Children and Young Adults Conceived by In Vitro Fertilization
- 2010
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In: PEDIATRICS. - : American Academy of Pediatrics; 1999. - 0031-4005 .- 1098-4275. ; 126:2, s. E270-E276
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Journal article (peer-reviewed)abstract
- OBJECTIVES: Studies conducted so far have found no statistically significant increased risk for cancer among children who are born after in vitro fertilization (IVF). METHODS: We followed 26 692 children who were born after IVF during the years 1982-2005 by using the Swedish Cancer Register and compared the number of children who had cancer and were born after IVF with children who were not conceived by IVF. Adjustment was made for year of birth. RESULTS: Maternal age, parity, smoking, subfertility, previous miscarriages, BMI, and multiple births did not significantly affect cancer risk in offspring. High birth weight, premature delivery, and the presence of respiratory diagnoses and low Apgar score were risk factors for cancer. We identified 53 cases of cancer in children who were born after IVF against 38 expected cases: 18 of them with hematologic cancer (15 of them acute lymphoblastic leukemia), 17 with eye or central nervous system tumors, and 12 with other solid cancers. There were 6 cases of Langerhans histiocytosis against 1.0 expected. The total cancer risk estimate was 1.42 (95% confidence interval: 1.09-1.87). CONCLUSIONS: We found a moderately increased risk for cancer in children who were conceived by IVF. Putative intermediary factors could be preterm birth and neonatal asphyxia.
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13. |
- Källén, Bengt, et al.
(author)
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Cerebral palsy in children born after in vitro fertilization. Is the risk decreasing?
- 2010
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In: European journal of paediatric neurology. - : Elsevier Science B.V., Amsterdam. - 1090-3798 .- 1532-2130. ; 14:6, s. 526-530
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Journal article (peer-reviewed)abstract
- Background: Infants born after in vitro fertilization (IVF) differ from spontaneously conceived infants in a number of aspects which could increase the risk for future cerebral palsy (CP), e.g., multiple births, preterm births, neonatal complications. Aims: To follow up children conceived by IVF with respect to risk for CP. Methods: Infants born after IVF were identified from all IVF clinics in Sweden 1982-2007. Perinatal characteristics were obtained by linkage with the Medical Birth Register. The presence of CP in children born after IVF and in other children was identified from the Patient Register which contains diagnoses given at hospitalizations or specialist outpatient clinics. The risk for CP after IVF was studied after adjustment for year of birth, maternal age, parity, and smoking, all factors which co-vary both with IVF and with CP. Stratification was made for singletons and multiple births and for various neonatal outcomes. Results: The adjusted odds ratio for CP after IVF was 1.81 (95% confidence interval, 95% CI 1.52-2.13), lower and not statistically significant when singletons or when unlike-sexed twins were analyzed. Stratification for various neonatal characteristics also reduced odds ratios to non-significant levels. For the last few years of the study (2004-2007) when the twinning rate after IVF was less than10%, the odds ratio for CP was 0.97 (95% CI 0.57-1.66). Conclusions: The moderately increased risk for CP was most likely a consequence of an increased risk of neonatal morbidity, notably associated with multiple births.
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14. |
- Källén, Bengt, et al.
(author)
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Congenital Malformations in Infants Born after In Vitro Fertilization in Sweden
- 2010
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In: BIRTH DEFECTS RESEARCH PART A-CLINICAL AND MOLECULAR TERATOLOGY. - : John Wiley andamp; Sons, Ltd. - 1542-0752 .- 1542-0760. ; 88:3, s. 137-143
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Journal article (peer-reviewed)abstract
- BACKGROUND: The risk for congenital malformations is increased in infants born after in vitro fertilization (IVF). Some specific malformations appear to be more affected than others. METHODS: The presence of congenital malformations in 15,570 infants born after IVF with an embryo transfer between April 1, 2001, and the end of 2006 were compared with all infants born in Sweden during 2001 to 2007 (n = 689,157). Risk estimates were made after adjusting for year of birth, maternal age, parity, smoking, and body mass index. The risks of specific malformations were compared with data from a previous study (1982 to March 31, 2001) of 16,280 infants born after IVF. Different IVF methods were compared to respect to malformation risk. RESULTS: Increased risks of a similar magnitude were found for most cardiovascular malformations and limb reduction defects for both study periods. For neural tube defects, cardiac septal defects, and esophageal atresia, there was still an increased risk, but it was lower during the second than during the first period. For small bowel atresia, anal atresia, and hypospadias, the risk increase observed during the first study period had disappeared during the second period. An increased risk was seen for some syndromes that have been associated with imprinting errors. No difference in malformation risk according to IVF method was apparent. CONCLUSIONS: A slightly increased risk for congenital malformations after IVF persists. A decreasing risk is seen for some specific malformations, either true or the result of multiple testing.
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15. |
- Källén, Bengt, et al.
(author)
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Delivery outcome after maternal use of drugs for migraine: a register study in sweden.
- 2011
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In: Drug Safety. - : Springer Science and Business Media LLC. - 1179-1942 .- 0114-5916. ; 34:8, s. 691-703
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Journal article (peer-reviewed)abstract
- Background: The use of drugs for migraine during pregnancy may have adverse effects on delivery outcome, and warnings exist for such drugs regarding use during pregnancy. Most information in the literature concerns triptans. Objective: The aim of the study was to describe the delivery outcome when a woman had used drugs for migraine during pregnancy. Study Design: A register study where exposure for drugs was obtained partly by interview conducted by the attending antenatal care midwife and medical records from antenatal care (1995-2008) and partly by linkage to the Prescribed Drug Register (2005-8). Setting: All deliveries in Sweden (1 211 670 women) recorded in the Medical Birth Register with data from antenatal care. Patients: Women using triptans or ergots during pregnancy were identified and compared with all women who did not use drugs for migraine. Main Outcome Measures: Pregnancy complications, pregnancy duration and birthweight, neonatal morbidity and mortality, and congenital malformations. Results: Use of ergots or triptans during early pregnancy (first trimester) occurred in 3286 women with 3327 infants, while use after the first trimester occurred in 1394 women with 1419 infants. Women using such drugs for migraine were older than other women, were more often of parity 1 (no previous infant) and more often had a high body mass index. Women using drugs for migraine had not previously had more miscarriages than expected. There was an increased risk for pre-eclampsia (odds ratio [OR] 1.44; 95% CI 1.17, 1.76). An increased risk for preterm birth was seen after use of drugs for migraine later in pregnancy (OR 1.50; 95% CI 1.22, 1.84). There was no increased risk for stillbirth or early neonatal death. No certain signs of teratogenicity were found for any of the drug types when compared with women not using such drugs (OR for any malformation 0.95; 95% CI 0.80, 1.12). Conclusions: Our data suggest that the risk of adverse effects on pregnancy outcome associated with the use of drugs for migraine is low but data for triptans other than sumatriptan are still few.
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16. |
- Källén, Bengt, et al.
(author)
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In vitro fertilization in Sweden : Maternal characteristics
- 2005
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In: Acta Obstetricia et Gynecologica Scandinavica. - : Wiley. - 0001-6349 .- 1600-0412. ; 84:12, s. 1185-1191
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Journal article (peer-reviewed)abstract
- Background. Deliveries among women who had an in vitro fertilization (IVF) are characterized by increased risks for both the mother and the infant/child. Part of these effects may be due to maternal characteristics. Methods. Using reports from all clinics performing IVF in Sweden, 12 186 women who gave birth after such procedures were identified (13 261 deliveries, 16 280 infants born). Various social and medical characteristics of the women were studied and compared with all women giving birth. Information was retrieved by interviews in early pregnancy or by linkage with various registers. Results. Women who had IVF were older than other women who gave birth and were older after standard IVF than after intracytoplasmatic sperm injection (ICSI). They were more often of first parity and smoked less than other delivered women. There were more women with high body mass index: they worked outside home less often and were more often of Swedish nationality. Women who had standard IVF had more previous miscarriages than expected, but this was not true for women who had ICSI. Their pattern of drug usage differed from that of other women who had given birth. Conclusions. Women who underwent IVF and gave birth showed marked deviations from other women who gave birth. Some of these characteristics may help to explain the increased risks associated with these procedures. Women who had ICSI were less deviating than women who had standard IVF. © Acta Obstet Gynecol Scand 2005.
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17. |
- Källén, Bengt, et al.
(author)
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In vitro fertilization in Sweden : Child morbidity including cancer risk
- 2005
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In: Fertility and Sterility. - : Elsevier BV. - 0015-0282 .- 1556-5653. ; 84:3, s. 605-610
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Journal article (peer-reviewed)abstract
- Objective: To study long-term morbidity among children conceived by IVF. Design: A register study in Sweden of IVF infants compared with all infants born. Setting: National health registers. Patient(s): More than 16,000 children born after IVF (30% of them after intracytoplasmic sperm injection) were studied with national health registers. Main Outcome Measure(s): Total number of days in hospital care at different ages, hospitalization for specific diagnoses, childhood cancer. Result(s): An overuse of hospital care was found among IVF children up to 6 years of age, which was partly explained by maternal characteristics. Discharge diagnoses indicating brain damage (mental retardation, cerebral palsy, epilepsy, behavioral problems) occurred in excess and seemed to be completely explained by preterm births. In addition, other discharge diagnoses were overrepresented, some of them linked to preterm birth. There were 29 children with cancer (21 expected), 5 of them had Langerhan's histiocytosis. Conclusion(s): Long-term morbidity among children conceived by IVF is higher than among naturally conceived infants. This was partly explained by an excess of preterm and multiple births but might also mirror different parental attitudes toward medical care for their children. No general increase in cancer risk was seen, but unexpectedly many children with histiocytosis were noted. ©2005 by American Society for Reproductive Medicine.
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18. |
- Källén, Bengt, et al.
(author)
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In vitro fertilization (IVF) in Sweden : Infant outcome after different IVF fertilization methods
- 2005
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In: Fertility and Sterility. - : Elsevier BV. - 0015-0282 .- 1556-5653. ; 84:3, s. 611-617
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Journal article (peer-reviewed)abstract
- Objective: To compare infant outcome after different IVF techniques. Design: A register study in Sweden of IVF infants compared with all infants born. Setting: National health registers. Patient(s): We studied 16,280 IVF infants, 30% of whom were conceived by intracytoplasmic sperm injection (ICSI). Intervention(s): None. Main Outcome Measure(s): Multiple births, infant sex, preterm birth, low birth weight, and small for gestational age among singletons, mortality, low Apgar score, neonatal diagnoses. Result(s): Twinning was less frequent after frozen standard IVF (18.1%) and after ICSI (21.8%) than after fresh standard IVF (24.4%). The male/female ratio was significantly increased in infants conceived after standard IVF. No significant differences were seen between singleton infants conceived after different IVF methods with respect to preterm birth, low birth weight, or infant mortality, with the possible exception of frozen standard IVF, for which some of these rates were lower than after fresh standard IVF. Infants born after ICSI had an indicated lower risk of respiratory problems than infants born after standard IVF. Conclusion(s): Little difference in outcome was seen after different IVF methods. The differences observed might be due to dissimilar characteristics of the treated women (e.g., because ICSI was mainly used in connection with male infertility). ©2005 by American Society for Reproductive Medicine.
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19. |
- Källén, Bengt, et al.
(author)
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In vitro fertilization (IVF) in Sweden : Risk for congenital malformations after different IVF methods
- 2005
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In: Birth defects research. Clinical and molecular teratology. - : Wiley. - 1542-0752 .- 1542-0760. ; 73:3, s. 162-169
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Journal article (peer-reviewed)abstract
- BACKGROUND: The possible excess of congenital malformations in infants born after in vitro fertilization (IVF) has been much discussed in the literature, with controversial conclusions. This population based study is aimed at analyzing the presence of congenital malformations in a large group of infants born after IVF and to compare malformation risk both with that of all infants born and according to IVF method used. METHODS: Infants born after IVF during the period 1982-2001 were ascertained from all IVF clinics in Sweden. The presence of congenital malformations was identified from three national health registers: the Swedish Medical Birth Register, the Swedish Registry of Congenital Malformations, and the Swedish Hospital Discharge Register. The IVF children were compared with all children born in Sweden during the same period and recorded in the Swedish Medical Birth Register. RESULTS: Among 16,280 IVF children (30% conceived after intracytoplasmatic sperm injection [ICSI]) a 42% excess of any congenital malformation was found, explainable by parental characteristics and in some cases by the high rate of multiple births. Among these children, 8% had a congenital malformation, and 15% had a relatively severe condition. For neural tube defects, choanal atresia, and alimentary tract atresia, an additional risk increase was seen. There was no difference in malformation rate according to IVF method except for an excess of hypospadias after ICSI. CONCLUSIONS: An increased risk for congenital malformations occurs after IVF, similar for the different IVF techniques used, and mainly a consequence of parental characteristics. A few specific conditions show an extra increase in risk. © 2005 Wiley-Liss, Inc.
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21. |
- Källén, Bengt, et al.
(author)
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Is there an increased risk for drug treated attention deficit/hyperactivity disorder in children born after in vitro fertilization?
- 2011
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In: EUROPEAN JOURNAL OF PAEDIATRIC NEUROLOGY. - : Elsevier Science B.V., Amsterdam. - 1090-3798. ; 15:3, s. 247-253
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Journal article (peer-reviewed)abstract
- Background: There is mounting evidence that children born after in vitro fertilization (IVF) run an increased risk of neurological complications and notably cerebral palsy. Whether developmental disturbances occur more often than expected is debated. Aim: To investigate the risk for ADHD in children conceived after IVF. Methods: Children conceived after IVF and born between 1982 and 2005 were identified from all IVF clinics in Sweden. Children who developed attention deficit/hyperactivity disorder (ADHD) were identified with the use of a register over all prescribed drugs in Sweden, using prescriptions for methylphenidate or atomixetine as indicators of ADHD. Maternal and neonatal characteristics were obtained by linkage with the Medical Birth Register and relevant confounders were adjusted for using Mantel-Haenszel procedures. We studied 28158 children born after IVF and compared them with 2417886 children in the population. Results: After adjustment for year of birth, maternal age, parity, smoking, BMI, and maternal education and after exclusion of women who did not cohabit, a weak but statistically significant association was found with an odds ratio = 1.18, 95% confidence interval 1.03-1.36. The effect was stronger in girls (OR = 1.40) than boys (OR = 1.11) but this difference could be random. After adjustment for length of involuntary childlessness, the OR decreased slightly and lost statistical significance. Conclusions: The study suggests a weak association between IVF and drug treated ADHD.
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22. |
- Källén, Bengt, et al.
(author)
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Maternal and fetal factors which affect fetometry: use of in vitro fertilization and birth register data
- 2013
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In: European Journal of Obstetrics, Gynecology, and Reproductive Biology. - : Elsevier. - 0301-2115 .- 1872-7654. ; 170:2, s. 372-376
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Journal article (peer-reviewed)abstract
- Background: Fetometry dating of gestational age is the gold standard in most developed countries but may have some inborn errors. Dating pregnancies after in vitro fertilization can be used for the evaluation of fetometric studies and for studies of variables which may affect them. less thanbrgreater than less thanbrgreater thanMethods: We compared the actual gestational age of 9543 singleton and 869 twin pregnancies with estimates based on second-trimester fetometry. Mean gestational age, percentage of births classified as preterm, and skewness of the distribution of differences between actual and estimated gestational age were studied. Subanalyses were made of data on singletons for males and females, for infants born to overweight or obese women or to smoking women, for infants judged to be small or large for gestational age, and on twins. less thanbrgreater than less thanbrgreater thanResults: In the majority of cases, good agreement was found between actual and estimated gestational age but in singletons there was an excess of positive differences resulting in a moderate over-estimate of the rate of preterm births (8%), more marked for females (11%) than for males (6%) and increased for infants born to overweight (7%) or obese (16%) mothers. Singleton infants born small for gestational age also showed an excess of positive differences (3%). These differences were less marked for twins. less thanbrgreater than less thanbrgreater thanConclusions: In most IVF pregnancies, routine fetometry correctly predicts gestational age but deviations exist which indicate that ultrasound underestimates the age of fetuses that will be born small for gestational age and when the woman is obese. The differences between actual age and estimates based on fetometry seem to be smaller than those between estimates based on last menstrual period and fetometry.
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23. |
- Källén, Bengt, et al.
(author)
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Maternal drug use during pregnancy and asthma risk among children
- 2013
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In: Pediatric Allergy and Immunology. - : John Wiley and Sons. - 0905-6157 .- 1399-3038. ; 24:1, s. 28-32
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Journal article (peer-reviewed)abstract
- Background Maternal use of some drugs, notably paracetamol and drugs for gastroesophageal reflux, has been associated with an increased risk of childhood asthma in the child. We wanted to analyze these associations with consideration to the confounding of maternal asthma. Methods Childhood asthma was identified from the Swedish National Prescription Register and maternal drug use during the latter part of pregnancy from antenatal records, computerized in the Swedish Medical Birth Register. Risks were estimated as odds ratios (OR) with 95% confidence intervals, using MantelHaenszel technique with adjustment for year of birth, maternal age, parity, smoking habits, and BMI. Results A statistical association between maternal use of many different drugs, including paracetamol, and childhood asthma existed but was mainly due to concomitant drug use, related to maternal asthma. The only associations that appeared to be true were with drugs for gastroesophageal reflux (adjusted (OR) = 1.32, 95% CI, 1.181.54) and with opiates (adjusted OR = 1.56 (96% CI, 1.052.34). Conclusions Maternal use of paracetamol did not seem to increase the risk of childhood asthma, but the previously described association with drugs for gastroesophageal reflux was supported. The analysis is complicated by the confounding from maternal asthma.
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24. |
- Källén, Bengt, et al.
(author)
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Maternal use of loperamide in early pregnancy and delivery outcome.
- 2008
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In: Acta Pædiatrica. - : Wiley. - 1651-2227 .- 0803-5253. ; 97:5, s. 541-545
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Journal article (peer-reviewed)abstract
- Aim: To study delivery outcome including presence of infant congenital malformations after maternal use of loperamide in early pregnancy. Methods: Using the Swedish Medical Birth Register, women reporting the use of loperamide in early pregnancy were compared with other women for the period July 1, 1995-2004. Odds ratios (OR) or risk ratios (RR) were estimated after adjustment for some variables, which were associated with the use of loperamide (year of delivery, maternal age, parity, smoking, number of previous miscarriages). Results: Characteristics of women using loperamide in early pregnancy were identified. An analysis of concomitant drug use indicated that only few of the women had inflammatory bowel disease. The risk of any congenital malformation was increased (OR = 1.43, 95% CI 1.04-1.96), based on 43 cases, but no major contributing type could be identified. The risk of hypospadias was significantly increased (RR = 3.2, 95% CI 1.3-6.6), based on seven cases. A statistically significant increase was seen also for placenta previa, large for gestational age and caesarean section. Conclusion: Maternal use of loperamide in early pregnancy may be associated with a moderate risk increase for a malformation in the infant. The finding should be evaluated from other large studies.
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25. |
- Källén, Bengt, et al.
(author)
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Maternal use of selective serotonin re-uptake inhibitors and persistent pulmonary hypertension of the newborn.
- 2008
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In: Pharmacoepidemiology and Drug Safety. - : Wiley. - 1053-8569 .- 1099-1557. ; 17, s. 801-806
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Journal article (peer-reviewed)abstract
- In order to evaluate the previously published association between maternal use of selective serotonin re-uptake inhibitors (SSRI) and persistent pulmonary hypertension in the neonate (PPHN), we used data from the Swedish Medical Birth Register for the years 1997-2005. Infants were identified from discharge diagnoses, and maternal exposure to drugs from interviews performed in early pregnancy and from prescriptions from the antenatal care service. Putative confounders were studied: an increased risk for PPHN was indicated for high maternal age, for first parity, for maternal BMI, and possibly for maternal smoking. Adjusting for these variables and year of birth, an association between maternal use of SSRI and PPHN in births after 34 completed weeks was identified with a risk ratio of 2.4, 95%CI 1.2-4.3 when based on women who reported the drug use in early pregnancy. When a subgroup of the women were studied who also had prescriptions for SSRI from the antenatal care later in pregnancy, the risk estimate was 3.6, 95%CI 1.2-8.3. The risk estimates were lower than that described previously in the literature, but both estimates could come from the same about 4-5 times increased risk. The mechanism behind the association between SSRI and PPHN is unclear but an increased risk for respiratory problems after maternal use of SSRI is well known, and PPHN could be a rare part of this association. Copyright (c) 2008 John Wiley & Sons, Ltd.
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26. |
- Källén, Bengt, et al.
(author)
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Maternal use of selective serotonin re-uptake inhibitors in early pregnancy and infant congenital malformations.
- 2007
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In: Birth Defects Research. Part A: Clinical and Molecular Teratology. - : Wiley. - 1542-0760 .- 1542-0752. ; 79:4, s. 301-308
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Journal article (peer-reviewed)abstract
- BACKGROUND: Maternal use of selective serotonin re-uptake inhibitors (SSRIs) has recently been associated with an increased risk for certain malformations. METHODS: Using the Swedish Medical Birth Register, we identified women who had reported the use of SSRIs in early pregnancy and studied their infants, born between July 1, 1995 and the end of 2004. Congenital malformations were identified from that register, from the Register of Congenital Malformations, and from the Hospital Discharge Register. The effect of drug exposure was studied after adjustment for a number of identified maternal characteristics that could act as confounders. RESULTS: We identified 6,481 women who reported the use of SSRIs in early pregnancy and their 6,555 infants. There was no general increase in malformation risk. An increased risk for cystic kidneys was seen, but this was based on only nine malformed infants, and the pathology varied between these cases. An in-depth study of cardiovascular defects identified an association between such defects and notably ventricular and atrial septum defects and maternal use of paroxetine but not other SSRls. No support for a postulated association between SSRI use and infant craniostenosis or omphalocele was found. CONCLUSIONS: Use of SSRIs in early pregnancy does not seem to be a major risk factor for infant malformations. The association between paroxetine use and infant cardiovascular defects may be a result of multiple testing, but is supported by other studies.
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27. |
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28. |
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29. |
- Källén, Bengt, et al.
(author)
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Use of anti-asthmatic drugs during pregnancy. 1. Maternal characteristics, pregnancy and delivery complications.
- 2007
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In: European Journal of Clinical Pharmacology. - : Springer Science and Business Media LLC. - 1432-1041 .- 0031-6970. ; 63, s. 363-373
-
Journal article (peer-reviewed)abstract
- Objective To study, in a large cohort, the association between the use of anti-asthmatic drugs during pregnancy and pregnancy complications. Methods Using the Swedish Medical Birth Register, we identified 24,369 women who reported the use of anti-asthmatic drugs in early pregnancy and 7778 women who were prescribed such drugs later during pregnancy by antenatal care system centres, during the period July 1, 1995 up to and including 2004. We studied maternal characteristics and pregnancy and delivery complications. Comparisons were made with all women having given birth to a child recorded in the register during this period. Results Women using anti-asthmatic drugs were characterized by a young maternal age, low parity, increased rate of smoking, low education, and high body mass index. An association with subfertility was also observed. Pre-existing diabetes did not occur in excess. A number of pregnancy and delivery complications occurred at an increased rate with the use of anti-asthmatic drugs, notably when three or more such drugs had been used: gestational diabetes [odds ratio (OR) = 1.59], preeclampsia (OR=1.44), haemorrhage at delivery (OR=1.32) and premature rupture of membranes (OR=1.59); no excess of placenta abruption or previa was found. Primary weak contractions occurred more often than expected in women that used anti-asthmatic drugs (OR=1.15), and this was tentatively linked to the use of beta-2 adrenergic agonists. Most of the increased risk for caesarean section (OR=1.79) could be explained by these pregnancy complications. An increased risk for delivery induction (OR=1.74) was found among deliveries that did not start with a caesarean section. Conclusion An increase risk of pregnancy complications occurs with the use of anti-asthmatic drugs by pregnant women, which results in an increased rate of caesarean sections.
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30. |
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31. |
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32. |
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33. |
- Lennestål, Roland, et al.
(author)
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Maternal use of antihypertensive drugs in early pregnancy and delivery outcome, notably the presence of congenital heart defects in the infants
- 2009
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In: European Journal of Clinical Pharmacology. - : Springer Science and Business Media LLC. - 1432-1041 .- 0031-6970. ; 65:6, s. 615-625
-
Journal article (peer-reviewed)abstract
- Purpose To investigate the association between maternal use of antihypertensives in early pregnancy and delivery outcome, notably infant congenital malformations. Methods A cohort study of 1,418 women who had used antihypertensive drugs in early pregnancy but had no diabetes diagnosis were identified from the Swedish Medical Birth Register. Results There was an excess risk for placental abruption, caesarean section, delivery induction, and post-delivery hemorrhage in women taking hypertensives. Infants were more often than expected born preterm, were small for gestational age, and had an excess of various neonatal symptoms. Cardiovascular defects occurred with an adjusted odds ratio of 2.59 (95% CI 1.92-3.51). The results were similar when the woman had used ACE inhibitors or other antihypertensives, notably beta blockers. Stillbirth rate was increased (risk ratio 1.87, 95% CI 1.02-3.02), again without any clear drug specificity. Conclusions There seems to be little drug specificity in the association between maternal use of antihypertensives and an increased risk for infant cardiovascular defects.
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34. |
- Ludvigsson, Jonas F, et al.
(author)
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External review and validation of the Swedish national inpatient register.
- 2011
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In: BMC Public Health. - : BioMed Central. - 1471-2458. ; 11, s. 450-
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Journal article (peer-reviewed)abstract
- BACKGROUND: The Swedish National Inpatient Register (IPR), also called the Hospital Discharge Register, is a principal source of data for numerous research projects. The IPR is part of the National Patient Register. The Swedish IPR was launched in 1964 (psychiatric diagnoses from 1973) but complete coverage did not begin until 1987. Currently, more than 99% of all somatic (including surgery) and psychiatric hospital discharges are registered in the IPR. A previous validation of the IPR by the National Board of Health and Welfare showed that 85-95% of all diagnoses in the IPR are valid. The current paper describes the history, structure, coverage and quality of the Swedish IPR. METHODS AND RESULTS: In January 2010, we searched the medical databases, Medline and HighWire, using the search algorithm "validat* (inpatient or hospital discharge) Sweden". We also contacted 218 members of the Swedish Society of Epidemiology and an additional 201 medical researchers to identify papers that had validated the IPR. In total, 132 papers were reviewed. The positive predictive value (PPV) was found to differ between diagnoses in the IPR, but is generally 85-95%. CONCLUSIONS: In conclusion, the validity of the Swedish IPR is high for many but not all diagnoses. The long follow-up makes the register particularly suitable for large-scale population-based research, but for certain research areas the use of other health registers, such as the Swedish Cancer Register, may be more suitable.
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35. |
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36. |
- Nilsson, Emma, et al.
(author)
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Schizophrenia and offspring's risk for adverse pregnancy outcomes and infant death
- 2008
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In: British Journal of Psychiatry. - : Royal College of Psychiatrists. - 0007-1250 .- 1472-1465. ; 193:4, s. 311-315
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Journal article (peer-reviewed)abstract
- Background Women with schizophrenia are at increased risk for adverse pregnancy outcomes. it is not known whether offspring born to fathers with schizophrenia also have an increased risk. Aims To evaluate paternal and maternal influences on the association between schizophrenia and pregnancy outcomes. Method A record linkage including 2 million births was made using Swedish population-based registers. The risk for adverse pregnancy outcomes was evaluated through logistic regression. Results Offspring with a mother or father with schizophrenia faced a doubled risk of infant mortality, which could not be explained by maternal behaviour alone during pregnancy. Excess infant death risk was largely attributable to post-neonatal death. Maternal factors (e.g. smoking) explained most of the other risks of adverse pregnancy outcomes among both mothers and fathers with schizophrenia. Conclusions The risks to offspring whose fathers had schizophrenia suggest that, in addition to maternal risk behaviour, non-optimal social and/or parenting circumstances are of importance. Results Offspring with a mother or father with schizophrenia faced
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37. |
- Nygren, Karl-Gosta, et al.
(author)
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Population-based Swedish studies of outcomes after in vitro fertilisation
- 2007
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In: Acta Obstetricia et Gynecologica Scandinavica. - : Wiley. - 1600-0412 .- 0001-6349. ; 86:7, s. 774-782
-
Research review (peer-reviewed)abstract
- Background. Various outcomes have been described during pregnancy and among infants born to women after in vitro fertilisation (IVF) treatments. This mini-review summarises recent population-based Swedish studies about the short- and long-term effects of IVF on the infant and child, and also comments on disturbances of pregnancies and deliveries occurring after IVF. Methods. Data on women who had IVF treatments and gave birth in Sweden during the period 1982-2001 were collected from all clinics performing IVF. By linkage with the Swedish Medical Birth Register, the Swedish Register of Congenital Malformations, the Swedish Hospital Discharge Register, the Swedish Cancer Register, and the Swedish Cause of Death Register, data on short- and long-term complications were retrieved. Results. From 1982 to 2001, a total of 13,261 women gave birth to 16,280 infants after IVF treatment. During the final years of the study, nearly half of the pregnancies occurred after intracytoplasmic sperm injection (ICSI). Characteristics of women who delivered after IVF were analysed. Various anomalies in pregnancy and delivery outcome were found, but few long-term effects. Conclusions. Most deviations, except for multiple pregnancies, could be explained by parents characteristics, notably their subfertility status. Little difference was found between pregnancies after standard IVF and pregnancies after ICSI.
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38. |
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39. |
- Otterblad Olausson, Petra
(author)
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Teenage childbearing : pregnancy outcomes and long-term consequences for the mothers
- 2000
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Doctoral thesis (other academic/artistic)abstract
- The purposes of the thesis were to study effects of low maternal age on adverse pregnancy outcomes, predictors of teenage childbearing, and long-term effects of teenage motherhood on the women's social situation later in life and risk of premature death. The effects of low maternal age at first birth on risks of adverse pregnancy outcomes, primarily preterm birth and infant mortality, were studied in three population-based cohort studies. We used the Swedish Medical Birth Register, the 1990 Population Census, and the population-based Education Register. The poorer pregnancy outcomes among teenagers aged 18-19 years are mainly an effect of a less favourable socio-economic situation. Infants of younger teenage mothers face an overall increased risk of preterm birth, neonatal and postneonatal mortality that is independent of socio-economic situation. The increased risk of neonatal mortality is entirely an effect of the increased risk of preterm birth. To study whether the increase in risk of poor pregnancy outcomes is due to low age per se, we also studied pregnancy outcomes at second birth in relation to age at first birth. When teenage childbearers had their second birth in adulthood, the risk of preterm birth has declined more than the corresponding risk decline among mother who also had their first birth in adulthood. Our results support the hypothesis that young age is a risk factor for poor pregnancy outcomes, independent of socio-economic conditions. To study familial and environmental effect as predictors of teenage childbearing, we linked the Swedish Twin Register to the Medical Birth Register. We used quantitative genetic analyses to evaluate the impact of genetic and environmental factors on the risk of teenage childbearing. We estimated the effect of life style factors, socio-economic situation, and personality traits on the likelihood of teenage childbearing, and if these factors could explain possible familial effects. Both familial and other environmental factors are important as predictors of teenage childbearing. We found significant effects of smoking habits, housing conditions, and educational level on the risk of teenage childbearing. However, the familial effect on teenage childbearing was not mediated by these factors. In two studies we analysed long-term socio-economic conditions and premature mortality of teenage mothers. We linked the following population-based registers: the Population Register, several Censuses, the Education Register, the Cause of Death Register, and a register of dependence on social welfare and disability pensions. Teenage childbearers face a considerably increased risk of a less favourable situation later in life. They are more likely to be not gainfully employed, to have an unskilled occupation, to be single mothers, to have four or five infants, to be dependent on social welfare and receive disability pensions. Teenage mothers also face an increase in risk of premature death due to in particular cervical cancer, ischaemic heart disease, suicide and inflicted violence. The increased risk of as well a less favourable social situation as premature mortality was independent of background socioeconomic status.
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41. |
- Stuart, Andrea, et al.
(author)
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Apgar scores at 5 minutes after birth in relation to school performance at 16 years of age.
- 2011
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In: Obstetrics and Gynecology. - 1873-233X. ; 118:2 Pt 1, s. 201-208
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Journal article (peer-reviewed)abstract
- OBJECTIVE: : To estimate the association between an Apgar score of less than 7 at 5 minutes after birth and long-term cognitive function. METHODS: : A linkage between the Swedish Medical Birth Registry and the Swedish School Grade Registry was performed. All singletons born from 1973 to 1986 after 36 6/7 weeks of gestation to Swedish-born women were included. Fetuses that were stillborn, newborns who had congenital malformations or were small for gestational age, and children who died or emigrated before 16 years of age were excluded from the analysis. RESULTS: : The study included 877,618 individuals in the analysis. Newborns with Apgar scores less than 7 at 5 minutes after birth showed a significantly increased risk of never receiving graduation grades, presumably because they went to special schools because of cognitive impairment or other special educational needs (odds ratio 1.93, 95% confidence interval 1.75-2.14). One out of 44 newborns (numbers needed to harm) with an Apgar score of less than 7 at 5 minutes after birth will go to a special school because of the antenatal or perinatal factors that caused the low Apgar score. Nearly all school children who had Apgar scores of less than 7 at 5 minutes after birth showed an increased risk of graduating from compulsory school without graduation grades in that specific subject or receiving the lowest possible grades and were also less likely to receive the highest possible grade. CONCLUSION: : An Apgar score of less than 7 at 5 minutes after birth is associated with subtle cognitive impairment, as measured by academic achievement at 16 years of age. LEVEL OF EVIDENCE: : II.
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42. |
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43. |
- Tornqvist, Kristina, et al.
(author)
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Ocular Malformations or Poor Visual Acuity in Children Born After In Vitro Fertilization in Sweden
- 2010
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In: American Journal of Ophthalmology. - : Elsevier Science B.V., Amsterdam.. - 0002-9394 .- 1879-1891. ; 150:1, s. 23-26
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Journal article (peer-reviewed)abstract
- PURPOSE: To follow up children born after in vitro fertilization (IVF) with respect to eye malformations and poor visual acuity. DESIGN: Observational cohort study based on Swedish health registers. METHODS: Congenital eye malformations were studied in 32 091 children born from 1982 through 2007 and severe visual impairment was studied in 24 628 children born from 1985 through 2005 after IVF in Sweden. Comparisons were made with all children born in Sweden during corresponding periods with adjustment for various confounders. The main outcome measure was the presence of a congenital eye malformation and poor visual acuity. RESULTS: Thirty-six (1.1 per 1000) IVF infants with ocular malformations were identified, and the risk, compared with non-IVF children, was not increased when adjusted for maternal age, parity, smoking, and body mass index (odds ratio, 1.05; 95% confidence interval, 0.75 to 1.47). Severe visual impairment was identified in 25 cases (1.0 per 1000), and the risk increase was statistically significant (odds ratio, 1.65; 95% confidence interval, 1.12 to 2.45) and was only slightly reduced when adjustment as above was made (odds ratio, 1.55; 95% confidence interval, 1.04 to 2.32). When adjustment was made for known length of unwanted childlessness, the OR decreased to 1.15 (95% confidence interval, 0.61 to 2.16). Only 3 of the 25 children with visual impairment had ocular malformations. CONCLUSIONS: Although there is an increased risk for visual impairment among children born after IVF, the individual risk is small and may be secondary to parental characteristics. No increased risk for eye malformations was found. (Am J Ophthalmol 2010;150:23-26.
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