London (CNN)More than half of pregnant women admitted to UK hospitals with Covid-19 were from black or other ethnic minority groups, according to a national study published Monday in the BMJ medical journal.
More than half of pregnant women in UK hospitals with Covid-19 are minorities, study finds
Researchers led by the University of Oxford's Nuffield Department of Population Health warned that although transmission of the virus to infants was uncommon and most women had "good outcomes," the high proportion of infected women from black or minority backgrounds "needs urgent investigation and explanation."
A separate government review by Public Health England found last week that members from the UK's ethnic minority communities are up to 50% more likely to die with coronavirus than their white British peers.
The latest study is based on data from the UK's Obstetric Surveillance System, a national system established to study a range of rare disorders of pregnancy.
The researchers said that of 427 pregnant women admitted to hospital with Covid-19 between March 1 and April 14, more than half were from minority groups, including 25% who were Asian and 22% who were black.
Most of the women were in their late second or third trimester, 70% were overweight or obese, 40% were aged 35 or over, and a third had pre-existing conditions, the researchers said.
The study noted that while published evidence on the rate, transmission and effect of coronavirus infection in pregnancy is limited, some evidence had suggested that pregnant women and their babies are at greater risk of severe illness and death.
However, an April study published in the American Journal of Obstetrics & Gynecolocy found that the majority of pregnant women who are diagnosed with coronavirus don't experience more severe illness than the general population.