A study into the effect of SARS-CoV-2 in pregnancy has provided reassurance for pregnant women and their babies.

Over the past few months, a huge number of studies have been published in medical journals about COVID-19, but studies including pregnant women are very under-represented.

This study, which is the largest analysis of SARS-CoV-2 in pregnancy, analysed the findings of 86 studies from all over the world that reported on 2567 pregnant women diagnosed with SARS-CoV-2.

More than one third (38%) of these women were obese and 33% had pre-existing medical conditions, such as diabetes, heart or lung problems. As in non-pregnant individuals with this infection, the most common symptoms were fever (63%) and cough (71%).

The risk of premature birth before 37 weeks’ gestation (22%) was increased, usually medically indicated due to the infection, rather than due to the woman going into premature labour. Almost half (48%) were delivered by caesarean section.

Around 7% of women were admitted to intensive care units, half of whom required treatment on a ventilator; and around 1 in 100 women died. These figures are very similar to those for non-pregnant women of similar age. Only 1.4% of babies had a positive swab in the newborn period.

This study, published in EClinicalMedicine at the Lancet, provides reassurance that SARS-CoV-19 infection is no worse in pregnant women than in non-pregnant women of the same age. It is probable that the virus can pass from mother to baby in the womb, but in a very small proportion of cases, and the effects on those babies are usually minimal. It seems likely that BAME women are at higher risk of COVID-19, mirroring the findings in the non-pregnant population.

Professor Asma Khalil, Study Lead and Consultant in Obstetrics and Maternal Fetal Medicine at St George’s, said: “This meta-analysis presents data from the largest number of pregnancies with SARS-CoV-2 reported to date. We hope that the findings would inform better counselling of women during the pandemic. Even though the risk of pre-term birth and Caesarean section is increased, the data does not suggest that pregnant women are at higher risk of severe COVID complications than non-pregnant women of a similar age.”

Notes to editors

Watch a video presentation from Professor Khalil on Twitter.

Interviews with Professor Khalil are also available. Please contact Pippa Harper, Media Manager, via philippa.harper@stgeorges.nhs.uk