No safe level of caffeine consumption for pregnant women and would-be mothers

Maternal caffeine consumption and pregnancy outcomes: a narrative review with implications for advice to mothers and mothers-to-be

Maternal caffeine consumption was associated with increased risk for four adverse outcomes:

• miscarriage, stillbirth, low birth weight, childhood acute leukaemia;
• in addition, observational studies reported significant associations with childhood weight and obesity.

The dose-responsive nature of the associations between caffeine and adverse pregnancy outcomes, and the fact some studies found no threshold below which negative outcomes were absent, supports likely-causation rather than mere association.