Science in the News Pres.

• There are other variants that researchers identified during this study and they are doing further research to determine whether they correlate with GDF15 and/or signalling pregnancy
• More research is being done on therapeutics targeting the GDF15 pathway and they are doing further investigation on Cancer Cachexia and chemotherapy induced nausea
• On the other hand, GDF15 causes Cancer Cachexia which has symptoms similar to HG
• GDF15 could potentially be a factor that protects against maternal immune attack
• NVP is hypothesized to have evolved as a mechanism for pregnant women to avoid consuming foods that could disturb the fetus
• GDF15 is not only genetic but also a cellular stress hormone produced in response to nutrient deficiencies, long-term fasting, hyperthyroidism, and infection which are all associated with HG and may explain why genetic predispositions can lead to its development from regular Nausea and Vomiting in Pregnancy (NVP)
• Higher levels of the hormone are associated with second-trimester vomiting and hospitalisation
• GDF15 activates the vomiting center of the brain through other brain receptors 
• GDF15 is mostly expressed by the placenta and increases significantly in the first trimester 
• There is now research that supports the causal role for GDF15 and pregnancy sickness 
• Harmfulness -> Groups who reported experiencing HG had higher miscarriage rates than the control group, this confirmed the harmfulness of HG
• Consistency -> One variant that was consistent among all women who experienced HG was the GDF15 hormone
• Genetics -> This study provided genetic evidence that GDF15, and genes associated with it, correlates with the risk of developing HG
• Table 1: Displays self-reports of women who developed HG during pregnancy and the number of live births and spontaneous abortions experienced between women who had HG and those that didn’t 
• Table 2: Shows the difference in genomes, and number of people affected by HG among different races/ancestries of people
• They also hope to test another class of drugs that may block GDF15 from bonding to receptors in the brain 
• Moving Forward, researchers intend to test whether pre-exposure to GDF15 prior to pregnancy can reduce pregnancy sickness (nausea and vomiting) and/or prevent HG
• They used animals to test the effects of GDF15 exposure and observed appetite loss (indicative of nausea) in mice that were exposed to levels similar to what is produced during pregnancy
• Patients that have Beta Thalassemia, a genetic blood disorder that causes high levels of GDF15, are protected from HG and other forms of pregnancy sickness 
• To clarify the link between GDF15 and pregnancy sickness, researchers observed a mutation in the gene that codes for GDF15 leading to low levels of the hormone and putting women who are suddenly exposed to it during pregnancy at risk of developing HG 
• Ways to address pregnancy sickness includes: 

  • Lowering GDF15 in pregnant women and hopefully reduce the symptoms
  • Exposing women to GDF15 before becoming pregnant
• Extreme reactions to the hormone may cause women to experience Hyperemesis Gravidarum (HG) which can lead to weight loss, dehydration, and hospitalization and may therefore put both the mother and the fetus at risk
• Women who are exposed to the hormone before their pregnancy tend to have less severe symptoms than those who just begin producing high levels of GDF15
• Some women may be more sensitive to it and/or produce different amounts of it during their pregnancy
• Pregnancy sickness can be attributed to a hormone produced in the placenta called GDF15