Caffeine consumption before pregnancy does not appear to affect the risk of miscarriage, but consumption during early pregnancy is associated with a small increased risk, according to a new study led by Boston University School of Public Health (BUSPH) researchers.

The study, published in the journal Human Reproduction, examined caffeine consumption among more than 5,000 women planning pregnancy who were enrolled in a Danish study between 2007 and 2010. Women reported their daily caffeinated beverage consumption on questionnaires before conception and during early pregnancy.

There were 732 women (14.3 percent) who were identified as having miscarriages. In the preconception period, caffeine consumption was not materially associated with miscarriage risk, the study found. But in early pregnancy, the risk associated with consuming 100–199 mg/day, 200–299 mg/day, and more than 300 mg/day was elevated, compared with consumption of less than 100 mg a day.

Dr. Kristen Hahn, a research fellow in the department of epidemiology at BUSPH and lead author of the study, said, “The results indicate that caffeine consumption in early pregnancy may be associated with a small increase in risk of miscarriage. Although our study is larger and improves on prior studies of this topic, our findings are still subject to various interpretations because there was no evidence of a dose-response effect with increasing consumption of caffeine in early pregnancy.”

To read more about the study, go to: http://www.bu.edu/sph/2015/04/14/caffeine-in-early-pregnancy-may-pose-miscarriage-risk/