But does this study carry enough weight to finally answer the question of whether pregnant women should give up caffeine altogether dr. Louis. Coffee is toxic stuff. Latest research to examine the risk of caffeine consumption during pregnancy reveals that women who said they drank more than two cups of coffee per day had nearly double the risk of miscarriage compared with women who consumed no caffeine. Some previous studies have shown that consuming caffeine during pregnancy increases a womans risk for miscarriage while others have found that drinking just a couple cups of coffee a day doesnt pose much of a threat. Researchers at the kaiser permanente research division in oakland calif.