Study finds nausea or nausea with vomiting in the early weeks of pregnancy significantly reduces the risk for pregnancy loss.
Approximately 80 percent of women experience nausea with or without vomiting during pregnancy. In addition to the discomfort associated with these symptoms, women often worry that they may be causing harm to their unborn child, particularly when nausea is accompanied by frequent vomiting. However, there has also been speculation that nausea and vomiting during pregnancy are indicative of a healthy pregnancy. Limited evidence supported this concept until now and prior studies enrolled women with clinically-recognized pregnancies, missing early losses.
A recent study, published in the Journal of American Medical Association (JAMA) Internal Medicine, examined the association between nausea and vomiting, and pregnancy loss.
The study evaluated data collected between 2007-2011 from 797 women with one or two pregnancy losses.
The women kept diaries and answered questionnaires during preconception and pregnancy where they recorded incidences of nausea, nausea and vomiting, or neither. A daily diary was used to quantify nausea and vomiting from week 2 (conception) until the pregnancy was confirmed in clinic, usually between weeks 6 and 8. Between weeks 12 and 36, pregnant women recorded their symptoms monthly, summarizing symptoms for the preceding 4 weeks. Data from the daily diaries and monthly questionnaires was converted into a weekly format for analysis.
Approximately 1 in 5 women reported experiencing nausea or nausea with vomiting before they had positive pregnancy test results: At gestational week 2, 18% of women reported nausea without vomiting, and 3% reported nausea combined with vomiting. By week 8, those numbers increased to 58% and 25% respectively. At week 12, 86% of women reported having nausea and 35% reported having nausea with vomiting at least once per week. Women who were younger than 25 years were more likely to experience nausea and vomiting than older women.
Of the 797 pregnancies, 188 (23.6%) ended in pregnancy loss, with the majority occurring in the first trimester. Women who experienced nausea or nausea with vomiting benefited from a 50% to 75% reduction in the risk for pregnancy loss compared with women who did not encounter these symptoms.
The authors conclude these results provide the most definitive data available associating nausea and vomiting with a reduced risk for pregnancy loss. This protective association may reassure women who experience these symptoms during pregnancy.
Written by: Lynn Kim