Moderate caffeine use and the risk of spontaneous abortion and intrauterine growth retardation.
OBJECTIVE
To examine the relationship between caffeine consumption during pregnancy and the occurrence of spontaneous abortion and intrauterine growth retardation.


METHODS
A cohort of 431 women, enrolled in a multicenter study within 21 days of conception, was monitored throughout pregnancy to determine (1) caffeine exposure, (2) exposure to other risk factors, (3) fetal growth as assessed by ultrasonography, and (4) pregnancy outcome.


METHODS
Spontaneous abortion, intrauterine growth, birth weight, and head circumference.


RESULTS
The mean (+/- SD) first-trimester caffeine consumption was not significantly higher in women who aborted (125.9 +/- 123.1 mg) than in women who delivered liveborn infants (111.6 +/- 107.0 mg) (P = 34). The adjusted odds ratio (OR) for spontaneous abortion was 1.15 (95% confidence interval [CI], 0.89 to 1.49). Early fetal growth, assessed by crown-rump length on ultrasonographic examination, was not affected by caffeine. Although the group consuming the most caffeine (> 300 mg/d) had a significantly higher proportion of babies with birth weights and head circumferences below the 10th percentile in the crude analysis, the association with caffeine was no longer significant when other risk factors (notably smoking) were taken into account. The adjusted ORs were 1.11 (95% CI, 0.88 to 1.40) for decreased birth weight and 1.09 (95% CI, 0.86 to 1.37) for smaller head circumference.


CONCLUSIONS
Close monitoring of a cohort identified very soon after conception enabled us to identify all abortions after 21 days postconception, monitor intrauterine growth prospectively, and track caffeine use. Despite this intensive surveillance, we found no evidence that moderate caffeine use increased the risk of spontaneous abortion, intrauterine growth retardation, or microcephaly after accounting for other risk factors.
Mills
J L
JL
Epidemiology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892.
Holmes
L B
LB
Aarons
J H
JH
Simpson
J L
JL
Brown
Z A
ZA
Jovanovic-Peterson
L G
LG
Conley
M R
MR
Graubard
B I
BI
Knopp
R H
RH
Metzger
B E
BE
D000022:Abortion, Spontaneous / Q000453:epidemiology / Q000209:etiology*; D000328:Adult; D002110:Caffeine / Q000009:adverse effects*; D015331:Cohort Studies; D005314:Embryonic and Fetal Development; D005260:Female; D005317:Fetal Growth Retardation / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology; D011446:Prospective Studies; D012044:Regression Analysis; D012307:Risk Factors; D016216:Ultrasonography, Prenatal
D002110:Caffeine