"The main message for pregnant women from these findings is that they probably should consider stopping caffeine consumption during pregnancy because this research provides clearer and stronger evidence that high doses of caffeine intake during pregnancy can increase the risk of miscarriage," said Li.
The reasons that caffeine can harm a fetus have been suspected for some time. Caffeine crosses through the placenta to the fetus, but can be difficult for the fetus to metabolize because of the under-developed metabolic system. Caffeine also may influence cell development and decrease placental blood flow, which may lead to an adverse effect on fetal development.
Women in the study were asked about their intake of caffeinated beverages as well as the type of their drinks, timing of initial drink, the frequency and amount of intake, and whether they changed consumption patterns since becoming pregnant. Sources of caffeine included coffee, tea, caffeinated soda and hot chocolate.
Researchers estimated the amount of caffeine intake in various types of beverages using the following conversion: For every 150 milliliters of beverage, 100 milligrams for caffeinated coffee, 2 milligrams for decaffeinated coffee, 39 milligrams for caffeinated tea, 15 milligrams for caffeinated soda, and 2 milligrams for hot chocolate. Information on other potential risk factors for miscarriage -- including maternal age, race, education, household income, marital status, smoking, alcohol consumption, hot tub use, exposure to magnetic fields during pregnancy, and symptoms related to pregnancy such as nausea and vomiting -- also were collected during the in-person interview and controlled during analyses. Pregnancy outcomes up to 20 weeks of gestation were determined for all participants.
Overall, 172 of women in the study (16.18 percent) miscar
|SOURCE Kaiser Permanente|
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