Original Article: PDF OnlyCaffeine Consumption during Pregnancy and Spontaneous AbortionFenster, Laura1; Eskenazi, Brenda2; Windham, Gayle C.1; Swan, Shanna H.1Author Information 1 From the Special Epidemiological Studies Program, Reproductive Epidemiology Program, Department of Health Services, Berkeley; and 2 Maternal and Child Health and Epidemiology, and the Northern California Occupational Health Center, School of Public Health, University of California, Berkeley. Address reprint requests to Laura Fenster, PhD, California Department of Health Services, Reproductive Epidemiology Program, Special Epidemiological Studies Program, 2151 Berkeley Way, Annex 11, Berkeley, CA 94704 Epidemiology: May 1991 - Volume 2 - Issue 3 - p 168-174 Free Abstract We conducted a case-control study of spontaneous abortion in Santa Clara County, California between 1986 and 1987– We analyzed data on 607 cases and 1,284 controls to evaluate the potential association between caffeine consumption during the first trimester of pregnancy and spontaneous abortion. About 70% of the women consumed caffeinated coffee, tea, and/or soda; 7% of the women consumed more than an average of 300 mg of caffeine daily. The crude odds ratio (OR) for heavy caffeine consumption (> 300 mg/day) was 1.55 (95% CI: 1.04–2.31), which decreased to 1.22 (95% CI: 0.80–1.87) after controlling for confounding factors. For these heavy users, nausea modified the association of spontaneous abortion and caffeine; heavy caffeine consumers reporting nausea had a doubled risk for spontaneous abortion (adjusted OR = 2.10, 95% CI: 1.20–3.70), in contrast to those who did not report nausea (adjusted OR = 0.5 3, 95% CI: 0.27–1.04). Heavy caffeine consumers who decreased their caffeine intake early in pregnancy had a risk of spontaneous abortion similar to that of nonconsumers © Lippincott-Raven Publishers.