Use of oral contraceptives in pregnancy and major structural birth defects in offspring.
BACKGROUND
Oral contraceptives (OCs) are the most commonly used reversible contraceptive method among US women. Although the majority of previous studies have reported no association between OC use during pregnancy and birth defects, some studies have reported increased occurrence of neural tube defects, limb reduction defects, and urinary tract anomalies.


METHODS
We assessed OC use among mothers who participated in the multisite, case-control, National Birth Defects Prevention Study. Mothers of 9986 infants with 32 types of birth defects and 4000 infants without birth defects were included.


RESULTS
Maternal OC use during the first 3 months of pregnancy was associated with an increased odds ratio for 2 of 32 birth defects: hypoplastic left heart syndrome (adjusted odds ratio = 2.3 [95% confidence interval = 1.3-4.3) and gastroschisis (1.8 [1.3-2.7]).


CONCLUSIONS
Previous reports of associations between OC use and specific types of anomalies were not corroborated. Given that associations were assessed for 32 types of birth defects, our findings of 2 increased associations between OC use and gastroschisis and hypoplastic left heart syndrome should be interpreted as hypotheses until they can be evaluated further. Overall, our findings are consistent with the majority of previous studies that found women who use OCs during early pregnancy have no increased risk for most types of major congenital malformations.
Waller
Dorothy Kim
DK
The University of Texas, Houston Health Science Center, School of Public Health, Houston, TX 77030, USA. Kim.Waller@uth.tmc.edu
Gallaway
Michael Shayne
MS
Taylor
Lockwood G
LG
Ramadhani
Tunu A
TA
Canfield
Mark A
MA
Scheuerle
Angela
A
Hernández-Diaz
Sonia
S
Louik
Carol
C
Correa
Adolfo
A
D000014:Abnormalities, Drug-Induced / Q000453:epidemiology / Q000209:etiology*; D000015:Abnormalities, Multiple / Q000139:chemically induced / Q000453:epidemiology; D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D016001:Confidence Intervals; D000013:Congenital Abnormalities / Q000453:epidemiology / Q000209:etiology; D003276:Contraceptives, Oral / Q000009:adverse effects*; D005260:Female; D020139:Gastroschisis / Q000139:chemically induced / Q000453:epidemiology; D006801:Humans; D018636:Hypoplastic Left Heart Syndrome / Q000139:chemically induced / Q000453:epidemiology; D016017:Odds Ratio; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000187:drug effects; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D014551:Urinary Tract / Q000002:abnormalities; D055815:Young Adult
D003276:Contraceptives, Oral