Is vomiting during pregnancy associated with risk for low birth weight babies?

Takeaway

• This study suggests that vomiting in early pregnancy, even when not perceived to be sufficiently severe to merit self-selected treatment with anti-emetics, is associated with an increased risk for a woman giving birth to a low birth weight (LBW) baby.

Why this matters

• The association between hyperemesis gravidarum and higher risk for LBW is reasonably well established; however, there is no clarity whether potentially less severe nausea or vomiting in pregnancy is associated with risk for delivering LBW babies.

Study design

• 1238 women in the Cambridge Baby Growth Study completed questionnaires related to adverse effects of pregnancy and drugs taken during pregnancy.
• Logistic regression was used to relate nausea and vomiting during pregnancy to the risk for giving birth to LBW (<2.5 kg) babies.
• Funding: Wellbeing of Women (the Royal College of Obstetricians and Gynaecologists, UK) and others.

Key results

• 467 women (38.3%) experienced nausea but not vomiting; 465 (38.2%) who experienced vomiting tended to be younger and more obese.
• Compared with women who did not experience vomiting or nausea, the delivery of LBW was more common in those who experienced vomiting in pregnancy (OR, 3.5; P=.03).
• The risk for giving birth to LBW babies was evident in women who experienced vomiting in the first trimester (OR, 4.3; P=.01) and second trimester (OR, 4.4; P=.01), but not in the third trimester (OR, 1.0; P=1.0).
• The higher risk was not evident in women who only experienced nausea (OR, 1.0; P=1.0).

Limitations

• Nausea and vomiting and the taking of any anti-emetics were self-reported.