In a case-control study of gastroschisis, we evaluated the risks assoc
iated with mother's first-trimester use of medications and with hobby
or occupational exposures for 110 cases and 220 controls without a bir
th defect. Mothers of cases and controls were age-matched. For hobby o
r occupational exposures, we found significantly elevated risks for hi
gh levels of solvents (odds ratio (OR) = 3.8; 95% confidence interval
(CI) 1.6-9.2) and for colorants (OR = 2.3; 95% CI 1.3-4.0). For medica
tions, we found significantly elevated risks for two strong cyclooxyge
nase inhibitors, aspirin (OR = 4.7; 95% CI = 1.2-18.1) and ibuprofen (
OR = 4.0; 95% CI = 1.0-16.0), but not for acetaminophen, a weak cycloo
xygenase inhibitor. Periconceptional exposure to X rays was also assoc
iated with gastroschisis (OR = 2.5; 95% CI = 1.2-5.5), but exposure to
antibiotics, antinauseants, sulfonamides, or oral contraceptives was
not. We also found elevated risks for two decongestants, pseudoephedri
ne (OR = 2.1; 95% CI = 0.8-5.5) and phenylpropanolamine (OR 10.0; 95%
CI = 1.2-85.6). For the group of all decongestants, including also oxy
metazoline and ephedrine, the risk was significantly elevated (OR = 2.
4; 95% CI = 1.0-5.4). Controlling in multivariate analyses for several
demographic and pregnancy variables associated with gastroschisis in
a previous analysis [Torfs et al. (1994) Teratology 50: 44-53] did not
substantially change the level or direction of the associations. Most
of these associations are for vasoactive substances, which supports a
vascular hypothesis for the pathogenesis of gastroschisis. (C) 1996 W
iley-Liss, Inc.