Periconceptional use of NuvaRing® or Ortho Evra™ and major structural birth defects in offspring
Background: Structural birth defects commonly occur during early pregnancy, when the mother may be unaware of her pregnancy. Exposure to medications during early pregnancy needs to be evaluated to characterize fetal safety. The majority of studies evaluating the use of oral contraception by mothers in early pregnancy found no association with most categories of structural birth defects when compared with mothers who used no hormonal contraception. Fetal safety from using the contraceptive vaginal ring, NuvaRing® , or the contraceptive transdermal patch, Ortho Evra™, during early pregnancy has not been independently evaluated. Methods: A case control study was conducted using data from the National Birth Defect Prevention Study to separately assess if maternal use of NuvaRing® or OrthoEvra™ in early pregnancy was associated with increased odds of 32 categories of structural birth defects in the offspring. Mothers who reported no hormonal contraception use were the referent group for all odds ratios. The analysis included 16,336 cases and 6,182 controls. Results: We conducted 72 statistical tests and observed 18 significantly elevated odds ratios for the association between maternal use of these contraception methods and specific categories of structural birth defects. Five significantly elevated odds ratios were associated with reported use of Ortho Evra™ in the first 3 months of pregnancy. There were no significantly elevated odds ratios for reported use of NuvaRing® in the first 3 months of pregnancy. The highest observed odds ratio was 11.51 (95% CI 3.28, 40.37) for renal agenesis in the offspring of mothers who reported last using NuvaRing® 2-3 months prior to conception. Conclusions: We observed 18 statistically significant odds ratios and would expect 3.6 odds ratios to be statistically significant if the results of this study were explained by chance alone. These results should be interpreted cautiously, however, because some of the elevated odds ratios that we observed were based on small numbers of exposed cases, which limited both the precision of our estimates and our ability to adjust for multiple potential confounders. Further studies of the association between maternal exposure to these two contraceptive methods and maternal exposure to specific formulations of oral contraceptives are needed to ensure that specific types of progestins or estrogens present in contraceptives are not associated with an increased risk of specific categories of structural birth defects.
Hallmark, Amy, "Periconceptional use of NuvaRing® or Ortho Evra™ and major structural birth defects in offspring" (2015). Texas Medical Center Dissertations (via ProQuest). AAI10036278.