Media release

From: Springer Nature

Investigating the cause of nausea and sickness in pregnancy 

A link between increased levels of a hormone and nausea during pregnancy (including morning sickness) is reported in a Nature study. The results shed light on these complex metabolic processes and offer potential avenues for treatment going forward.

The majority of pregnancies (70%) are affected by nausea and vomiting, which can progress to a severe form known as hyperemesis gravidarum (HG). The hormone growth differentiation factor 15 (GDF15) has previously been implicated in morning sickness in previous literature; however, the underlying mechanism has yet to be described.

Stephen O’Rahilly and colleagues measured levels of GDF15 in expectant mothers in their first trimester and found a notable link between elevated levels of GDF15 and reported nausea and vomiting (including HG). Further analysis of placental and maternal samples revealed that the fetus is responsible for the vast majority of the hormone circulating in the maternal plasma. The authors also found that lower levels of GDF15 prior to pregnancy are associated with a higher risk of developing HG. Conversely, women with β-thalassaemia (a condition in which GDF15 levels are chronically high) rarely reported nausea and vomiting in pregnancy. These results suggest that those with lower levels of GDF15 before pregnancy may be more sensitive to the increased levels of the hormone during pregnancy, and thus more affected by the sickness that it triggers.

These findings suggest there may be a causal relationship between fetal-derived GDF15 and the risk of HG: those who have lower initial levels of the hormone are more likely to experience sickness as the levels rise during the first trimester. Alice Hughes and Rachel Freathy write in an accompanying News & Views that the work “… is likely to prompt further investigations and an appetite for clinical trials in the field of pregnancy-related diseases.”