Caffeine use in pregnancy:
Coffee consumption and spontaneous abortion (a.k.a. miscarriage):
Non-smoking pregnant women who drank coffee were found to have an increased risk of losing their baby through spontaneous abortion in a study of 1,515 women (spontaneous abortion: 562, no spontaneous abortion: 953). Risk of spontaneous abortion was related to quantity of caffeine consumed. At 100 to 299 mg/d, 300 to 499 mg/d, and 500 mg/d or more of caffeine consumption risk of spontaneous abortion increased by 30%, 40%, and 120%, respectively. No increased risk of spontaneous abortion from caffeine was reported among women who smoked. Additionally, moderate to high consumption of caffeine was associated with an excess risk of spontaneous abortion in fetuses with normal chromosomes than in those classified as abnormal. (20)