Vomiting in pregnancy is associated with a higher risk of low birth weight: a cohort study.

Vomiting in early pregnancy, even when not perceived to be sufficiently severe to merit treatment, is associated with a higher risk of delivering a low birth weight baby. Early pregnancy vomiting might therefore be usable as a marker of higher risk of low birth weight in pregnancy. This may be of benefit in situations where routine ultrasound is not available to distinguish prematurity from fetal growth restriction, so low birth weight is used as an alternative.