Research
Obstetrics
Maternal caffeine consumption during pregnancy and the risk of miscarriage: a prospective cohort study

Presented at the 19th Annual Meeting of the Society for Pediatric and Perinatal Epidemiology, Seattle, WA, June 20-21, 2006.
https://doi.org/10.1016/j.ajog.2007.10.803Get rights and content

Objective

The objective of the study was to examine whether the risk of miscarriage is associated with caffeine consumption during pregnancy after controlling for pregnancy-related symptoms.

Study Design

This was a population-based prospective cohort study.

Results

An increasing dose of daily caffeine intake during pregnancy was associated with an increased risk of miscarriage, compared with no caffeine intake, with an adjusted hazard ratio (aHR) of 1.42 (95% confidence interval 0.93 to 2.15) for caffeine intake of less than 200 mg/day, and aHR of 2.23 (1.34 to 3.69) for intake of 200 or more mg/day, respectively. Nausea or vomiting during pregnancy did not materially affect this observed association, nor did the change in intake pattern of caffeine during pregnancy. In addition, the magnitude of the association appeared to be stronger among women without a history of miscarriage (aHR 2.33, 1.48 to 3.67) than that among women with such a history (aHR 0.81, 0.34 to 1.94).

Conclusion

Our results demonstrated that high doses of caffeine intake during pregnancy increase the risk of miscarriage, independent of pregnancy-related symptoms.

Section snippets

Materials and Methods

The study was conducted among pregnant members of the Kaiser Permanente Medical Care Program (KPMCP), a group model-integrated health care delivery system. During a 2 year period from October 1996 through October 1998, all KPMCP women who resided in the San Francisco and South San Francisco areas and had a positive pregnancy test in these facilities were identified as potentially eligible subjects. The KPMCP facilities require all women who suspect that they might be pregnant to undergo a

Results

Overall 172 of women (16.18%) miscarried. Whereas 264 women (25%) reported no consumption of any caffeine-containing beverages during pregnancy, 635 women (60%) reported 0-200 mg of caffeine intake per day, and 164 women (15%) had 200 mg or more of daily caffeine consumption. Table 1 compares the various characteristics of women who were at different levels of caffeine consumption. Caffeine intake was associated with a variety of risk factors for miscarriage, such as age of 35 years or older;

Comment

In this prospective cohort study, we demonstrated an elevated risk of miscarriage associated with caffeine consumption during pregnancy and a dose-response relationship with most of the risk associated with caffeine consumption at 200 mg or greater per day. This observed effect was independent of many potential confounders including pregnancy related symptoms such as nausea, vomiting, and aversion to caffeine consumption. Even among women who never changed caffeine consumption pattern during

Acknowledgment

De-Kun Li conceived the concept, designed the study, obtained funding, oversaw the data collection and analyses, and was involved in the interpretation of results and preparation of the manuscript. Xiaoping Weng was responsible for data analysis, interpretation of the data, and preparation of the manuscript. Roxana Odouli was involved in the data collection and preparation of the manuscript. De-Kun Li is the guarantor of this paper, who took full responsibility for the conduct of the study, had

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  • Cited by (0)

    This study was supported in part by the California Public Health Foundation.

    Cite this article as: Weng X, Odouli R, and Li D-K. Maternal caffeine consumption during pregnancy and the risk of miscarriage: a prospective cohort study. Am J Obstet Gynecol 2008;198:279.e1-279.e8.

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