More than half of pregnant women admitted to hospital in the UK with COVID-19 were from black or other ethnic minorities, a new study in the BMJ medical journal has revealed.
The reason behind this needs "urgent investigation and explanation," the authors say.
The study's lead author said her team was surprised by the high proportion of minorities even after taking into account other factors such as age, obesity, underlying medical problems and urban life.
"It's obviously very simplistic to think of black and minority ethnic women as a single group –there are many different groups. And I think it's likely that there will be many different factors playing a part across all of those groups," Marian Knight, a professor of maternal and child population health at the University of Oxford, told Euronews in a live TV interview.
Researchers examined data from the UK Obstetric Surveillance System for pregnant women admitted to all 194 obstetric units in the UK with confirmed COVID-19 infection between 1 March and 14 April 2020.
Over these six weeks, 427 pregnant women were admitted to hospital with COVID-19, most of them in the late second or third trimester.
More than half of them (56 per cent) were from black or other ethnic minority groups (25 per cent were Asian and 22 per cent were black), 70 per cent were overweight or obese, 40 per cent were aged 35 or over, and a third had pre-existing conditions.
The high proportion of women from minority groups remained even after excluding major urban centres (London, the West Midlands, and the northwest of England) from the analysis.
The authors wrote that this over-representation may reflect "a higher risk of infection, a higher risk of severe disease given infection among vulnerable subgroups, or both."
Ethnic disparities have been found in COVID-19 infection rates and deaths, notably in the United States. Various possible reasons have been suggested to explain them, including social and health behaviours, underlying conditions and genetic factors.
A recent report published by UK health authorities showed that people from minority groups, particularly of Bangladeshi ethnicity, were significantly more at risk of dying of COVID-19 than white Britons.
Pending more research, the latest findings should encourage pregnant women of colour to look out even more carefully for any symptoms, Knight said.
"What's really important for women is to know that they may be at higher risk, and therefore to know that it's really important to seek help early if they're at all concerned about symptoms," she said.
"For example, if they are severely breathless, or if they can't speak in sentences, those are very significant symptoms in the context of COVID-19."
The study also yielded some encouraging findings: the data collected, however limited, turned out to be somewhat reassuring as to the impact COVID-19 has on pregnant women and their babies.
It indeed suggested "that most women do not have severe illness and that transmission of infection to infants of infected mothers can occur but is uncommon."