| 2. |
- Westvik-Johari, Kjersti, et al.
(författare)
-
Separating parental and treatment contributions to perinatal health after fresh and frozen embryo transfer in assisted reproduction: A cohort study with within-sibship analysis.
- 2021
-
Ingår i: PLoS medicine. - : Public Library of Science (PLoS). - 1549-1676. ; 18:6
-
Tidskriftsartikel (refereegranskat)abstract
- Compared to naturally conceived children, adverse perinatal outcomes are more common among children born after assisted reproductive technology with fresh embryo transfer (fresh-ET) or frozen embryo transfer (frozen-ET). However, most previous studies could not adequately control for family confounding factors such as subfertility. We compared birth size and duration of pregnancy among infants born after fresh-ET or frozen-ET versus natural conception, using a within-sibship design to account for confounding by maternal factors.This registry-based cohort study with nationwide data from Denmark (1994-2014), Norway (1988-2015), and Sweden (1988-2015) consisted of 4,510,790 live-born singletons, 4,414,703 from natural conception, 78,095 from fresh-ET, and 17,990 from frozen-ET. We identified 33,056 offspring sibling groups with the same mother, conceived by at least 2 different conception methods. Outcomes were mean birthweight, small and large for gestational age, mean gestational age, preterm (<37 weeks, versus ≥37), and very preterm birth (<32 weeks, versus ≥32). Singletons born after fresh-ET had lower mean birthweight (-51 g, 95% CI -58 to -45, p < 0.001) and increased odds of small for gestational age (odds ratio [OR] 1.20, 95% CI 1.08 to 1.34, p < 0.001), while those born after frozen-ET had higher mean birthweight (82 g, 95% CI 70 to 94, p < 0.001) and increased odds of large for gestational age (OR 1.84, 95% CI 1.56 to 2.17, p < 0.001), compared to naturally conceived siblings. Conventional population analyses gave similar results. Compared to naturally conceived siblings, mean gestational age was lower after fresh-ET (-1.0 days, 95% CI -1.2 to -0.8, p < 0.001), but not after frozen-ET (0.3 days, 95% CI 0.0 to 0.6, p = 0.028). There were increased odds of preterm birth after fresh-ET (OR 1.27, 95% CI 1.17 to 1.37, p < 0.001), and in most models after frozen-ET, versus naturally conceived siblings, with somewhat stronger associations in population analyses. For very preterm birth, population analyses showed increased odds for both fresh-ET (OR 2.03, 95% CI 1.90 to 2.12, p < 0.001) and frozen-ET (OR 1.66, 95% CI 1.42 to 1.94, p < 0.001) compared with natural conception, but results were notably attenuated within siblings (OR 1.18, 95% CI 1.0 to 1.41, p = 0.059, and OR 0.92, 95% CI 0.67 to 1.27, p = 0.6, for fresh-ET and frozen-ET, respectively). Sensitivity analyses in full siblings, in siblings born within 3-year interval, by birth order, and restricting to single embryo transfers and blastocyst transfers were consistent with the main analyses. Main limitations were high proportions of missing data on maternal body mass index and smoking.We found that infants conceived by fresh-ET had lower birthweight and increased odds of small for gestational age, and those conceived by frozen-ET had higher birthweight and increased odds of large for gestational age. Conception by either fresh-ET or frozen-ET was associated with increased odds of preterm birth. That these findings were observed within siblings, as well as in conventional multivariable population analyses, reduces the likelihood that they are explained by confounding or selection bias.ClinicalTrials.gov ISRCTN11780826.
|
|
| 3. |
- Henningsen, Anna-Karina A, et al.
(författare)
-
Infant and maternal health monitoring using a combined Nordic database on ART and safety.
- 2011
-
Ingår i: Acta obstetricia et gynecologica Scandinavica. - : Wiley. - 1600-0412 .- 0001-6349. ; 90:7, s. 683-691
-
Tidskriftsartikel (refereegranskat)abstract
- Objective. To evaluate infant and maternal health after assisted reproductive technology (ART), using data on over 90 000 ART children and their mothers in Denmark, Finland, Norway and Sweden. Data have been combined and will be compared with a control group of spontaneously conceived children and their mothers. The overall aim of this project is to evaluate the safety of ART. The size of the cohort should enable estimation of the prevalence of rare conditions such as birth defects, cancers, neurological impairments and imprinting diseases in the ART population compared to control children. Outcome data on the mothers of ART children can be used to study risks during pregnancy and obstetric complications after ART. Methods. A personal identification number given to all Nordic residents allows cross-linkage of the national health registers and enables long-term follow-up of ART children. The medical birth registers in the Nordic countries make it possible to cross-link data from mother and child. When a child is identified as conceived by ART, we can obtain a list of all International Classification of Diseases (ICD) codes ever registered on that specific child. Conclusion. Combining the Nordic ART and health registers is a complicated but feasible task. The main strengths of this ongoing study are the size of the cohort of ART children and their mothers and the possibility to follow the children through the health registers. The limitations are related to the national differences in reporting and recording of data together with the heterogeneity of data.
|
|
