Increased hormone level linked with nausea during pregnancy

A link between increased levels of a hormone and nausea during pregnancy, including morning sickness, is reported in new research A link between increased levels of a hormone and nausea during pregnancy, including morning sickness, is reported in new research.

The study, which is published in Nature and led by the University of Cambridge in collaboration with researchers from the University of Glasgow and others, sheds 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.

Researchers 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 --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.

The GlasBRU lab, run by Profs Welsh and Sattar, conducted many of the GDF-15 measurements included in the study.

Paul Welsh, Professor of Molecular Epidemiology at the University of Glasgow, said: "The identification of hyperemesis gravidarum as a condition where GDF-15 signalling may have a causal role in maternal sickness, and where effective treatments are notably absent, is particularly exciting and could have clinical ramifications."

Naveed Sattar, Professor of Cardiovascular & Metabolic Health, said: "The GDF-15 molecule is interesting, and other areas of research have suggested high levels may cause unintentional weight loss (cachexia) in people with other chronic conditions, leading companies to develop agents that may alleviate cachexia."

The study, ’Gdf15 linked to maternal risk of nausea and vomiting during pregnancy’, is published in Nature.