The Royal College of Obstetricians and Gynaecologists has welcomed a new study which sheds light on the association between COVID-19 and pregnancy outcomes.
The study by the National Maternity and Perinatal Audit found that pregnant women who tested positive for COVID-19 in England at the time of birth had higher rates of stillbirth or a preterm birth; however, the actual increases remain low.
Data were analysed from more than 340,000 births in England, in which around 3,500 women had tested positive for COVID-19 around the time of birth, between May 2020 and January 2021.
The study published in the American Journal of Obstetrics and Gynecology found:
- Women who tested positive for COVID-19 around the time of birth were twice as likely to have a stillbirth (8.5 in every 1000 births, compared with 3.4 in every 1000 births)
- The rate of premature birth was twice as high when the mother had COVID-19 at the time of birth
- Women who tested positive for COVID-19 were more likely to have an emergency caesarean birth compared with those who didn’t have COVID-19 at birth
- No other adverse neonatal outcomes were seen, other than those related to preterm birth
- It was more common for women who had COVID-19 at the time of birth to be younger and from a Black, Asian or minority ethnic background.
Professor Asma Khalil, professor of obstetrics and maternal fetal medicine at St George’s, University of London, consultant at St George’s Hospital, obstetric lead of the National Maternity and Perinatal Audit and co-lead author on the paper, said: “This study is the largest yet in England to describe the pregnancy outcomes in pregnant women who had tested positive for COVID-19 around the time of birth.
"While it is reassuring that the overall increases in the rate of stillbirth and preterm birth remain low, this study does show that the risk of stillbirth or premature birth may be increased in women who have the infection around the time of birth. This highlights the importance of COVID-19 vaccination for pregnant women; it reduces the risk not just to themselves, but also to their babies”
Professor Jan van der Meulen, professor of clinic epidemiology at the London School of Hygiene and Tropical Medicine and co-lead author on the paper, said: “It’s important we interpret these findings with caution, as we only have information about COVID-19 infection at the time of birth. It is possible that our results can be partly explained by differences in infection rates during different periods of pregnancy: women towards the end of their pregnancy may have been less likely to catch the virus than women earlier in pregnancy, as advice to women and to their employers has focused on the risks of COVID in late pregnancy after 28 weeks gestation."
Dr. Pat O’Brien, consultant obstetrician and vice president at the Royal College of Obstetricians and Gynaecologists, said: “These findings are important. While they do show that the rates of stillbirth and preterm birth were higher for mothers testing positive for COVID-19 at the time of birth compared with those who didn’t have the virus, we want to reassure women that the numbers are still very low.
“However, every stillbirth is a tragedy and prematurity can have serious consequences for some babies, so this study highlights the importance of protecting pregnant women from this virus, as it also helps to protect their babies.
“We’re very pleased that pregnant women are now being offered either the Pfizer-BioNTech or Moderna vaccine when their age group is called, in line with the national rollout. This study shows the importance of women being offered protection from the virus. We would encourage pregnant women to use the RCOG’s decision aid to discuss the benefits and risks of vaccination with a healthcare professional so they can make an informed choice.”
The full study can be found here: https://www.ajog.org/article/S0002-9378(21)00565-2/fulltext