Nausea and vomiting in pregnancy : prevalence and relationship with psychosocial determinants of health

Abstract

Nausea and vomiting are commonly experienced by women in pregnancy (NVP). Symptoms are usually limited to the first trimester, but can persist until birth. Both mild and more severe symptoms can have negative effects for the mother, her unborn child, and the family. Despite the frequency of NVP and associated distress, the exact cause is unknown and the condition remains poorly understood.

This secondary analysis explores nausea and vomiting in pregnancy, as determined by the Nausea and Vomiting in Pregnancy Instrument (NVPI), in a cohort of Canadian pregnant women at two gestational time points. The data analyzed in this study were originally from a longitudinal and epidemiological study of depression in pregnancy and into the postpartum. A population health approach has been used to examine psychosocial determinants of nausea and vomiting in pregnancy.

During the second trimester, the prevalence of nausea and vomiting in this sample of 551 women was 63.3%, with 24% of women reporting moderate nausea and vomiting and 18.9% reporting severe symptoms. These rates are similar to other studies of women during the first and second trimester of pregnancy. In the final model, nausea and vomiting in pregnancy was associated with gestation (weeks), antiemetic medication use, employment status, worry, and symptoms of major depression.

During the third trimester, the prevalence of NVP in this sample of 575 women was 45.4%, with 8.2% reporting moderate nausea and vomiting and 14.3% reporting severe symptoms. These results exceed previous reports on prevalence beyond 20 weeks in pregnancy. In the final model, nausea and vomiting in pregnancy was associated with antiemetic medication use, worry, and symptoms of major depression. The presence of support and maternal smoking were found to have a protective effect.

The co-morbidity of nausea and vomiting, worry, and symptoms of major depression in this sample of pregnant women represents a significant public and mental health problem. Care providers need to screen pregnant women for nausea and vomiting and also screen women for depression in the presence of more severe NVP symptoms. Supportive measures that address both conditions may be necessary in order to improve the quality of life of pregnant women, their families, and to protect the unborn child from the effects of both nausea and vomiting and depression in pregnancy.