Use of antihistamine medications during early pregnancy and isolated major malformations.
BACKGROUND
Antihistamines are commonly used during pregnancy. There is little evidence that they have teratogenic effects, but there are knowledge gaps with respect to newer products, as well as the relationship between specific antihistamines and specific birth defects.


METHODS
Using the National Birth Defects Prevention Study (1997-2003), the authors examined associations between maternal use of 14 antihistamines during early pregnancy and 26 isolated major birth defects. A Bayesian analysis incorporating prior knowledge about the relationships between antihistamines, birth defects, and measured covariates was conducted.


RESULTS
Of the 364 associations investigated, 24 had 95% posterior intervals excluding 1.0. All 24 associations were positive; 23 associations were of weak to moderate magnitude (posterior OR < 3.0) and one was strong (OR > 6.0) but very imprecise. Of the 24 associations, 20 were with noncardiac defects. Eight associations involved the antihistamine diphenhydramine.


CONCLUSIONS
The results of this study generally were consistent with no association between birth defects and antihistamine use during early pregnancy. Several of the findings might warrant further investigation, although the observed elevated associations should be interpreted in the context of the number of associations investigated and the analysis of retrospective, self-reported data.
Gilboa
Suzanne M
SM
National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, 1600 Clifton Rd., Atlanta, GA 30333, USA.
Strickland
Matthew J
MJ
Olshan
Andrew F
AF
Werler
Martha M
MM
Correa
Adolfo
A
D000014:Abnormalities, Drug-Induced / Q000453:epidemiology*; D016022:Case-Control Studies; D005260:Female; D006633:Histamine Antagonists / Q000009:adverse effects* / Q000627:therapeutic use*; D006801:Humans; D006967:Hypersensitivity / Q000188:drug therapy / Q000453:epidemiology; D007231:Infant, Newborn; D011247:Pregnancy; D011248:Pregnancy Complications / Q000188:drug therapy; D011261:Pregnancy Trimester, First / Q000187:drug effects; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced / Q000453:epidemiology*; D012189:Retrospective Studies
D006633:Histamine Antagonists