Studying sleep apnoea in obese pregnant women

Obese pregnant women are more likely to suffer from sleep apnoea, where breathing pauses during sleep. Our scientists are investigating how common sleep apnoea is, and what effects it has on mother and baby. This could lead to new ways of preventing some of the pregnancy complications linked to obesity.
  • Author's list

    Dr Emma Johns, Professor Rebecca Reynolds, Professor Fiona Denison, Dr Renata Riha

    Start date: February 2018
    End date: April 2021

  • Research centre

  • Research status

    Ongoing projects

Why do we need this research?

Being obese increases the chances of complications during pregnancy. One medical condition linked to obesity is sleep apnoea, where a person stops breathing during sleep for short periods of time. These episodes can lead to a decrease in oxygen in the blood.

Scientists believe that sleep apnoea in obese pregnant women might contribute to pregnancy complications such as gestational diabetes, high blood pressure, premature birth and stillbirth. However, we don’t know enough about this to be certain. We also don’t know what proportion of obese pregnant women have sleep apnoea, and how many women develop sleep apnoea in pregnancy who did not have it previously. This is preventing us from helping these women.

What’s happening in this project?

Researchers funded by Tommy’s set up the Sleep Easy study to better understand the impact and extent of sleep apnoea during pregnancy. The study included 77 pregnant women, some who were obese and some who had a normal weight. The women took part in two overnight sleep tests, during which they were asked to wear equipment that could detect sleep apnoea or other sleep breathing disorders. The women also provided answers to sleep questionnaires and donated samples of their blood and their baby’s placenta and cord blood after birth.

So far, our researchers have found that around one-third of the obese pregnant women in the study suffered from sleep apnoea in the second or third trimesters. This is in contrast to only 3–6% of women whose body weight was considered to be normal. Our researchers also found that standard sleep questionnaires were not very good at picking up on sleep apnoea in pregnant women. This means that some women may be unaware of their sleep apnoea and unable to seek help.

Our scientists next plan on studying the donated blood and placenta samples in order to find out more about the effect of sleep apnoea on both the mother and the baby. The team will also follow up with the children when they are older, to investigate if their mothers’ sleep apnoea causes any long-term effects for them.

What difference will this project make?

This project will help our scientists learn more about the effects of sleep apnoea during pregnancy on both the mother and her baby. Despite not being routinely screened for, our researchers believe that sleep apnoea contributes towards pregnancy complications in obese women. If this is the case, it may be possible to treat the sleep apnoea and therefore reduce the chances of these women experiencing complications during pregnancy.

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