Research suggests that women experiencing viable pregnancies are more likely to reduce their caffeine intake in response to the pregnancy signal than women who have a miscarriage1-4. Therefore, reduced caffeine consumption may be a consequence of pregnancy viability4.
The European Food Safety Authority (EFSA) in its Scientific Opinion on Caffeine concluded that pregnant women should limit their caffeine intake from all sources to 200mg per day during pregnancy5. Research suggests that moderate caffeine consumption of 200mg/day* does not increase the risk of any reproductive or perinatal complication5. This conclusion is based on prospective cohort studies showing a dose-dependent positive association between caffeine intakes during pregnancy and the risk of adverse birth weight-related outcomes (i.e. fetal growth retardation, small for gestational age)5. It is nevertheless difficult to define the association between caffeine and reproductive health as confounding factors such as changes in diet, smoking, and incorrect or imprecise assessment of the duration of exposure to caffeine may limit the ability to draw clear conclusions1.
Research suggests that coffee consumption is not associated with reduced fertility1,6-10, pre-term labour11,12, or fetal death1; or significantly associated with congenital malformations13-19, although further investigation is needed to confirm any suggested association with congenital malformations. Research on pregnancy loss20-28 and fetal growth1,13,29,30 gives some conflicting results and further work is required. While one paper suggests that moderate (i.e. less than 200mg/day) caffeine intake does not appear to be a major contributing factor in miscarriage23, another suggests that caffeine intakes of 300mg/day or more are associated with increases in late miscarriage, although the authors note remaining uncertainty in the strength of association24. A Cochrane Review concluded that there is insufficient data to confirm or refute the effectiveness of caffeine avoidance on birthweight or other pregnancy outcomes31..
The content in this Overview was last edited in August 2018. Papers in the Latest Research section and further resources are added regularly.