Morning sickness is a common condition for pregnant women, and the reasons for feeling this way are many. Fejzo and colleagues investigated the genetic information of a large group of women for genes linked to morning sickness.
Up to 18% of women take medication to manage nausea. However, despite its prevalence, morning sickness has no known cause. Morning sickness can be severe without treatment. It can result in vomiting, dehydration, weight loss, and nutritional deficiencies. The condition can sometimes lead to preterm birth and birth defects.
What genes affect pregnancy
In a study published in Nature Communications, Fejzo and colleagues investigated aspects of genes relating to morning sickness. The researchers used genetic data from female users of 23andMe. All were of European ancestry with 1,306 having experienced and received treatment. An additional 15,756 had reported no illness.
The researchers performed a genome-wide association study, to link specific gene variants to a characteristic of interest. In this case, the trait of interest was the occurrence of morning sickness.
Two genome locations were found that are potentially linked to morning sickness. One of these locations contains the genes GDF15 and LRRC25. Additionally, collateral genes that made the GDF15 active were also linked to morning sickness.
GDF15 encodes for a protein turned on in the placenta and increases throughout pregnancy. The main functions of this protein are to reduce inflammation, to help the development of the placenta, and to ensure the pregnancy is carried full-term. In addition, GDF15 plays a role in appetite and weight gain. The second gene, IGFBP7, also helps with the growth and maintenance of the placenta during pregnancy.
In the future, additional genome association studies will have to link the discussed genes to morning sickness in women of non-European ancestry. Future work will also have to determine the exact role of GDF15 and IGFBP7 in managing morning sickness.
Understanding these genes and how they work will help us understand why morning sickness exists in healthy women. Furthermore, more knowledge will provide potential targets for treating the condition.
- Fejzo, M.S., Sazonova, O.V., Sathirapongsasuti, J.F. et al. Placenta and appetite genes GDF15 and IGFBP7 are associated with hyperemesis gravidarum. Nat Commun 9, 1178 (2018). https://doi.org/10.1038/s41467-018-03258-0