First-trimester antihistamine exposure and risk of spontaneous abortion or preterm birth.
OBJECTIVE
We tested whether antihistamine exposure during early pregnancy is associated with spontaneous abortion (SAB) or preterm birth (PTB).


METHODS
Women were enrolled in Right from the Start (2004-2010), a prospective pregnancy cohort. Data about first-trimester antihistamine use were obtained from screening and first-trimester interviews. Self-reported outcomes included SAB and PTB and were verified by medical records. Cox proportional hazards models were used to test for an association between antihistamine use and each outcome, both performed adjusting for confounders.


RESULTS
Among the 2685 pregnancies analyzed, 14% (n = 377) reported use of antihistamines. Among antihistamine users, 12% (n = 44) experienced SABs, and 6% (n = 21) had PTBs. Antihistamine exposure was not associated with SAB (adjusted hazard ratio [aHR] = 0.88, 95% confidence interval [CI] 0.64, 1.21) or PTB, which was modified by maternal race (aHR = 1.03, 95%CI 0.61, 1.72 among White women and aHR = 0.43, 95%CI 0.14, 1.34 among Black women).


CONCLUSIONS
Despite the biologic plausibility that antihistamine use may influence pregnancy outcomes, we did not detect evidence of an association with SAB or PTB. These data demonstrate the utility of large prospective cohorts for evaluating drug safety in pregnancy when concerns are raised from animal models.
Vanderbilt Epidemiology Center, Nashville, TN, USA; Vanderbilt University, Institute of Medicine and Public Health, Nashville, TN, USA; Vanderbilt University, Department of Obstetrics and Gynecology, Nashville, TN, USA.
Tiara D
TD
Aldridge
Katherine E
KE
Hartmann
Kara A
KA
Michels
Digna R
DR
Velez Edwards
D000022:Abortion, Spontaneous / Q000139:chemically induced* / Q000453:epidemiology*; D000293:Adolescent; D000328:Adult; D005260:Female; D006633:Histamine Antagonists / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D006801:Humans; D018811:Maternal Exposure / Q000009:adverse effects*; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011446:Prospective Studies; D012306:Risk; D014481:United States / Q000453:epidemiology; D055815:Young Adult
D006633:Histamine Antagonists
histamine antagonists; pharmacoepidemiology; pregnancy; prospective studies