Prenatal alcohol exposure and risk of birth defects.
OBJECTIVE
The goal was to examine the associations between dose, pattern, and timing of prenatal alcohol exposure (PAE) and birth defects.


METHODS
Data from a randomly selected, population-based cohort of nonindigenous women who gave birth to a live infant in Western Australia (WA) between 1995 and 1997 (N=4714) were linked to WA Midwives Notification System and WA Birth Defects Registry data. We assessed the associations of PAE before pregnancy, in the first trimester, and in late pregnancy with any birth defect and with birth defects classified as alcohol-related birth defects (ARBDs) by the Institute of Medicine (IOM), by using logistic regression.


RESULTS
The prevalence of birth defects classified as ARBDs by the IOM was low. Compared with abstinence, heavy PAE in the first trimester was associated with increased odds of birth defects classified as ARBDs (adjusted odds ratio: 4.6 [95% confidence interval: 1.5-14.3]), with similar findings after validation through bootstrap analysis. There was no association between low or moderate PAE and birth defects.


CONCLUSIONS
A fourfold increased risk of birth defects classified as ARBDs was observed after heavy PAE in the first trimester. Many individual birth defects included in the IOM classification for ARBDs either were not present in this cohort or were not associated with PAE. Large, population-based studies are needed to strengthen the evidence base for ARBDs.
O'Leary
Colleen M
CM
Telethon Institute for Child Health Research, Centre for Child Health Research, Department of Health Economics, School of Population Health, University of Western Australia, PO Box 855, West Perth, WA 6872, Australia. colleeno@ichr.uwa.edu.au
Nassar
Natasha
N
Kurinczuk
Jennifer J
JJ
de Klerk
Nicholas
N
Geelhoed
Elizabeth
E
Elliott
Elizabeth J
EJ
Bower
Carol
C
D000014:Abnormalities, Drug-Induced / Q000209:etiology*; D000428:Alcohol Drinking / Q000009:adverse effects*; D005260:Female; D063647:Fetal Alcohol Spectrum Disorders; D006801:Humans; D007231:Infant, Newborn; D016017:Odds Ratio; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects