Bioethics Blogs

Morning Sickness Associated with Lower Miscarriage Risk


During the first trimester of pregnancy, many women experience what’s commonly known as “morning sickness.” As distressing as this nausea and vomiting can be, a team of NIH researchers has gathered some of the most convincing evidence to date that such symptoms may actually be a sign of something very positive: a lower risk of miscarriage.

In fact, when the researchers studied a group of women who had suffered one or two previous miscarriages, they found that the women who felt nauseous during their subsequent pregnancies were 50 to 75 percent less likely to miscarry than those without nausea. While it’s not yet exactly clear what’s going on, the findings lend support to the notion that morning sickness may arise from key biological factors that reflect an increased likelihood of a successful pregnancy.

The study, reported recently in JAMA Internal Medicine [1], was led by Enrique Schisterman and Stefanie Hinkle of the NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development. Their findings are based on a secondary analysis of existing data from the recently completed Effects of Aspirin in Gestation and Reproduction (EAGeR) trial. It found that aspirin might help in select cases but is not generally recommended to prevent pregnancy loss [2].

While other studies have looked at the effects of morning sickness on the risk of miscarriage, most have been limited to pregnancies lost late in the first trimester or thereafter. That’s one of the ways in which the EAGeR study is noteworthy. It enrolled 1,228 women who had one or two previous miscarriages and followed them for up to six menstrual cycles as they tried to become pregnant again.

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.