Is there a link between nutrient deficiency in women with severe vomiting in pregnancy and health complications for them and their babies?

Pregnancy is, for many women, an exciting and happy time. In early pregnancy, about 4 in 5 women will experience nausea and/or vomiting, commonly referred to as morning sickness. But some will experience a much more severe form called hyperemesis gravidarum (HG).

HG typically starts between the fourth and seventh week of pregnancy, peaking at around nine weeks. However, for 1 in 5 women with HG, the vomiting lasts throughout pregnancy. In women with HG, the nausea and vomiting are so severe that it can lead to weight loss and dehydration. It may also be associated with mental health consequences.

Nutritional deficiencies in women with hyperemesis gravidarum

Dr Nana’s study, co-funded by Wellbeing of Women and the Royal College of Physicians, involves:

1. Evaluating levels of specific nutritional deficiency throughout pregnancy in women with HG and their newborn babies compared to women with uncomplicated pregnancies.
2. Identifying specific deficiencies that are likely to contribute to the onset of neurodevelopmental or metabolic disorders in children of HG pregnancies.

To do this, her team is analysing blood samples from

• women with HG, taken at intervals throughout pregnancy
• the umbilical cord, collected at the time of birth.

Dr Nana’s team will also take a blood sample from the mother’s baby a few days after birth.

Researchers are focusing their work on deficiencies already linked to neurodevelopmental and metabolic disorders.

Dr Nana says:

“There is a growing suggestion that nutritional deficiencies can increase the risk of health-related complications for both the pregnant woman and her baby. This requires urgent investigation.

“In 2021 we carried out a study to try to understand the lived experience of women with HG in the UK. 5,000 women responded to the survey, which confirmed that those with the condition suffer both significant physical and mental health complications of the disease.

“We found that 70% of these women had been bed-bound during part of their pregnancy, 5% terminated a wanted pregnancy and 7% had regular suicidal thoughts. It was clear these women lose large amounts of weight and one key concern is how this weight loss of poor dietary intake will affect their unborn baby.

“The idea that nutritional deficiencies can increase the risk of health conditions in children isn’t new. We already know that children born to women exposed to famine are more likely to have schizophrenia, antisocial personality disorders, obesity, hypertension and heart disease. But we do need to understand the relationship and potential link between HG, nutritional deficiencies and neurodevelopmental and metabolic disorders. This will ensure we are able to support women through their pregnancies effectively.”

Research implications

Understanding the role of nutritional deficiency in the development of health-related complications for pregnant women with HG and neurodevelopmental and metabolic disorders in their children has the potential to inform future new treatments to improve the outcomes for women and their babies. This knowledge will allow doctors and midwives to support women more effectively in their pregnancies and give their babies the best start in life.

Learn more from Dr Melanie Nana in our webinar on HG

Wellbeing of Women is funding several research projects to help improve treatment and care during pregnancy and birth, including:

• Dr Jane Cleal’s study into why some women struggle to become pregnant or experience miscarriage
• Dr John Allotey’s work to reduce the rate of stillbirth by understanding early pregnancy risk factors
• An investigation by Dr Matina Iliodromiti into how we can identify health risks in babies too small or too large during pregnancy
• Midwife Joanne Cull investigating how maternity services can empower pregnant women affected by trauma