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- Terho, A M, et al.
(författare)
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High birth weight and large-for-gestational-age in singletons born after frozen compared to fresh embryo transfer, by gestational week: a Nordic register study from the CoNARTaS group.
- 2021
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Ingår i: Human reproduction (Oxford, England). - : Oxford University Press (OUP). - 1460-2350 .- 0268-1161. ; 36:4, s. 1083-1092
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Tidskriftsartikel (refereegranskat)abstract
- When do the differences in birth weights become apparent between singletons born after frozen embryo transfer (FET) and fresh embryo transfer (fresh ET)?Mean birth weights after FET become significantly higher starting from gestational week (GW) 33 among boys and from GW 34 among girls.In recent years, there has been a steep rise in recorded FET treatments, enabling widespread use of elective single embryo transfer, thus reducing the risks associated with multiple gestations. However, singletons born after FET are heavier and there is a higher risk of large-for-gestational-age (LGA) (birth weight > 90 percentiles) compared to fresh ET. In contrast, risk of small-for-gestational-age (SGA, birth weight < 10 percentiles) is lower in singletons born after FET compared to fresh ET. The reasons, timing and consequences of these differences remain largely unclear. There is limited evidence about whether this difference in growth develops before the last trimester of pregnancy.This retrospective Nordic register-based cohort study compared singletons born after FET (n=17500) to singletons born after fresh ET (n=69510) and natural conception (NC, n=3311588). All live born singletons born between the years 2000 and 2015 in Denmark, Norway and Sweden at gestational age ≥22weeks were included from the population-based Committee of Nordic ART and Safety (CoNARTaS) study population.Children born after FET were compared to those born after fresh ET and NC for mean birth weight and proportion of LGA and SGA for each GW at birth. Chi-square test and tests for relative proportions were used to compare categorical variables and Student's t-test was used to compare continuous variables. Adjusted odds ratios (aORs) for LGA and SGA were calculated using logistic regressions, adjusting for year of birth, maternal age, parity, BMI, chronic hypertension, diabetes, smoking and offspring sex.Mean birth weights were significantly higher after FET compared to fresh ET starting from GW 33 (range from 75g to 228g by week) for boys and starting from GW 34 (range from 90g to 236g by week) for girls. Boys born after FET had a significantly higher proportion of LGA (11.0-15.1%) at birth between GW 36 and 42, compared to those born after fresh ET (7.1-9.4%) (range from P<0.001 to P=0.048 by week). For girls born after FET, the difference was seen between GW 37 and 42 (10.6-13.4%) compared to those born after fresh ET (6.6-8.0%) (range from P<0.001 to P=0.009 by week).The proportion of SGA was significantly lower among boys born after FET (7.6-8.7%) compared to fresh ET (11.9-13.6%) between GW 36 and 42 (range from P<0.001 to P=0.016 by week). For girls born after FET, the difference was seen between GW 38 and 42 (7.0-9.3%) compared to those born after fresh ET (13.0-14.6%) (P<0.001). The proportion of LGA (12.3-15.1%) was significantly higher for boys born after FET between GW 38 and 41 (P<0.001) and for girls born after FET (12.6-13.4%) between GW 37 and 40 (range from P<0.001 to P=0.018 by week), compared to naturally conceived boys (9.7-9.9%) and girls (9.0-10.0%). All singletons born after FET had a higher risk of LGA compared to singletons born after fresh ET (aOR 1.87, 95% CI 1.76-1.98) and singletons born after NC (aOR 1.28, 95% CI 1.22-1.35).There may be residual confounding factors that we were not able to control for, most importantly the causes of preterm birth, which may also influence foetal growth. A further limitation is that we have no knowledge on growth patterns between implantation and GW 22. Finally, the number of children born extremely preterm or post-term was limited even in this large study population.This is, to date, the largest study on birth weights among preterm and term ART singletons with a population-based design and NC control group. The results suggest that the freeze-thaw process is associated with higher birthweights and greater risk of LGA at least in the last trimester of pregnancy. This is an important aspect of the safety profile of ART. More research is needed on the long-term outcome of these children.The CoNARTaS collaboration has received the following funding: the Nordic Trial Alliance: a pilot project jointly funded by the Nordic Council of Ministers and NordForsk [71450], the Central Norway Regional Health Authorities [46045000], the Norwegian Cancer Society [182356-2016], the Nordic Federation of Obstetrics and Gynaecology [NF13041, NF15058, NF16026 and NF17043], the Interreg Öresund-Kattegat-Skagerrak European Regional Development Fund (ReproUnion project) and the Research Council of Norway's Centre of Excellence funding scheme [262700]. None of the authors have any competing interests to declare.ISRCTN11780826.
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- Henningsen, A. A., et al.
(författare)
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Imprinting disorders in children born after ART: a Nordic study from the CoNARTaS group
- 2020
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Ingår i: Human Reproduction. - : Oxford University Press (OUP). - 0268-1161 .- 1460-2350. ; 35:5, s. 1178-1184
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Tidskriftsartikel (refereegranskat)abstract
- STUDY QUESTION: Is the risk of imprinting disorders increased in children conceived after ART? SUMMARY ANSWER: We found an adjusted odds ratio (AOR) of 2.84 [95% CI: 1.34-6.01] for Beckwith-Wiedemann syndrome in ART children, while the risk of Prader-Willi syndrome, Silver-Russell syndrome or Angelman syndrome was not increased in children conceived after ART. WHAT IS KNOWN ALREADY: Earlier studies, most of them small, have suggested an association between ART and imprinting disorders. STUDY DESIGN, SIZE, DURATION: This was a binational register-based cohort study. All children conceived by ART in Denmark (n = 45 393, born between 1994 and 2014) and in Finland (n = 29 244, born between 1990 and 2014) were identified. The full background populations born during the same time periods in the two countries were included as controls. Odds ratios of imprinting disorders in ART children compared with naturally conceived (NC) children were calculated. The median follow-up time was 8 years and 9 months for ART children and 11 years and 9 months for NC children. PARTICIPANTS/MATERIALS, SETTING, METHODS: From the national health registries in Denmark and Finland, we identified all children diagnosed with Prader-Willi syndrome (n = 143), Silver-Russell syndrome (n = 69), Beckwith-Wiedemann syndrome (n = 105) and Angelman syndrome (n = 72) born between 1994/1990 and 2014, respectively. MAIN RESULTS AND THE ROLE OF CHANCE: We identified a total of 388 children diagnosed with imprinting disorders; 16 of these were conceived after ART. The overall AOR for the four imprinting disorders in ART children compared with NC children was 1.35 [95% CI: 0.80-2.29], but since eight ART children were diagnosed with Beckwith-Wiedemann syndrome, the AOR for this specific imprinting disorder was 2.84 [95% CI: 1.34-6.01]. The absolute risk of Beckwith-Wiedemann syndrome in children conceived after ART was still low: 10.7 out of 100 000 newborns. The risks of Prader-Willi syndrome, Silver-Russell syndrome and Angelman syndrome were not increased in children conceived after ART. LIMITATIONS, REASONS FOR CAUTION: Imprinting disorders are rare events and our results are based on few ART children with imprinting disorders. The aetiology is complex and only partly clarified, and the clinical diagnoses are challenged by a broad phenotypic spectrum. WIDER IMPLICATIONS OF THE FINDINGS: In the existing studies, results on the risk of imprinting disorders in children conceived after ART are ambiguous. This study adds that the risk of imprinting disorders in ART children is very small and perhaps restricted to Beckwith-Wiedemann syndrome.
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- Henningsen, A. K. A., et al.
(författare)
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Risk of congenital malformations in live-born singletons conceived after intracytoplasmic sperm injection: a Nordic study from the CoNARTaS group
- 2023
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Ingår i: Fertility and Sterility. - 0015-0282 .- 1556-5653. ; 120:5, s. 1033-1041
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To investigate whether the risk of major congenital malformations is higher in live-born singletons conceived with intracytoplasmic sperm injection (ICSI) compared with in vitro fertilization (IVF)?Design: Nordic register-based cohort study.Setting: Cross-linked data from Medical Birth Registers and National ART and Patient Registers in Denmark, Norway and Sweden. Data were included from the year the first child conceived using ICSI was born: Sweden, 1992; Denmark, 1994; and Norway, 1996. Data were included until 2014 for Denmark and 2015 for Norway and Sweden. Patient(s): All live-born singletons conceived using fresh ICSI (n = 32,484); fresh IVF (n = 47,178); without medical assistance (n = 4,804,844); and cryo-ICSI (n = 7,200) during the study period. Intervention(s): Different in vitro conception methods, and cryopreservation of embryos.Main Outcome Measure(s): Risk of major congenital malformations on the basis of International Classification of Diseases codes. The European Concerted Action on Congenital Anomalies and Twins was used to differentiate between major and minor malformations. Result(s): Among singletons conceived using fresh ICSI, 6.0% had a major malformation, compared with 5.3% of children conceived using fresh IVF; 4.2% of children conceived without medical assistance; and 4.9% of children conceived using cryoICSI; adjusted odds ratio (AOR) 1.07 (95% confidence interval [CI] 1.01-1.14) in ICSI vs. IVF; and AOR 1.28 (95% CI, 1.23- 1.35) in ICSI vs. no medical assistance; and AOR 1.11 (95% CI, 0.99-1.26) in ICSI fresh vs. cryo-ICSI. When malformations were grouped by different organ systems, children conceived using ICSI had a higher risk of respiratory and chromosomal malformations compared with children conceived using IVF, but there were very few cases in each group. When categorizing children conceived using ICSI according to treatment indication (male factor infertility only vs. other indications), we found a higher risk of hypospadias when ICSI was performed because of male factor infertility only (AOR 1.85 [95% CI 1.03-332]). The indications for ICSI changed over time, as male factor infertility did not remain the primary indication for ICSI throughout the study period.Conclusion(s): In this large cohort study, we found the risk of major malformations in live-born singletons to be slightly higher after fresh ICSI compared with fresh IVF. These findings should be considered when choosing the assisted reproductive technology method for couples without male factor infertility. (Fertil Sterile 2023;120:1033-41. (c) 2023 by American Society for Reproductive Medicine.) El resumen esta disponible en Espanol al final del articulo.
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- Henningsen, A. K. A., et al.
(författare)
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Trends over time in congenital malformations in live-born children conceived after assisted reproductive technology
- 2018
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Ingår i: Acta Obstetricia Et Gynecologica Scandinavica. - : Wiley. - 0001-6349 .- 1600-0412. ; 97:7, s. 816-823
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Tidskriftsartikel (refereegranskat)abstract
- Children born after assisted reproductive technology, particularly singletons, have been shown to have an increased risk of congenital malformations compared with children born after spontaneous conception. We wished to study whether there has been a change in the past 20 years in the risk of major congenital malformations in children conceived after assisted reproductive technology compared with children spontaneously conceived. Material and methodsPopulation-based cohort study including 90 201 assisted reproductive technology children and 482 552 children spontaneously conceived, born in Denmark, Finland, Norway and Sweden. Both singletons and twins born after in vitro fertilization, intracytoplasmatic sperm injection and frozen embryo transfer were included. Data on children were taken from when the national Nordic assisted reproductive technology registries were established until 2007. Multiple logistic regression analyses were used to estimate the risks and adjusted odds ratios for congenital malformations in four time periods: 1988-1992, 1993-1997, 1998-2002 and 2003-2007. Only major malformations were included. ResultsThe absolute risk for singletons of being born with a major malformation was 3.4% among assisted reproductive technology children vs. 2.9% among children spontaneously conceived during the study period. The relative risk of being born with a major congenital malformation between all assisted reproductive technology children and children spontaneously conceived remained similar through all four time periods (p = 0.39). However, we found that over time the number of children diagnosed with a major malformation increased in both groups across all four time periods. ConclusionWhen comparing children conceived after assisted reproductive technology and spontaneously conceived, the relative risk of being born with a major congenital malformation did not change during the study period.
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