September 1, 2020

expert reaction to study looking at COVID-19 in pregnancy

Research, published in the BMJ, looked at COVID-19 in pregnancy.

Dr Edward Morris, President of the Royal College of Obstetricians and Gynaecologists, said:

“This living systematic review study is a welcome and comprehensive synthesis of the available research on COVID-19 in pregnancy, at a time when our knowledge is still evolving.

“While overall risks to pregnant women from coronavirus are low, the findings of this study highlight the particular risks to pregnant women, especially those in the third trimester of pregnancy, should they become unwell with coronavirus.  Pregnant women are included in the list of people at moderate risk as a precaution and pregnant women should therefore continue to follow the latest government guidance on social distancing and avoiding anyone with symptoms suggestive of coronavirus.

“We already know that emerging evidence has suggested that women of Black, Asian and ethnic minority backgrounds, including pregnant women, are at higher risk of developing severe complications of COVID-19.  RCOG/RCM guidance recommends that women of BAME background should be advised by healthcare professionals that they may be at higher risk of complications of COVID-19 and they should be encouraged to seek advice without delay if they are concerned about their health.

“This research also synthesises evidence that has shown that having co-morbidities, being older or overweight in pregnancy also increases the risk of experiencing poorer outcomes if the virus is contracted.  However, it is important that pregnant women are aware that the absolute risks to their health from coronavirus are low.

“This study highlights a possible increase in the need for intensive care among pregnant women with coronavirus.  This is also true for pregnant women should they contract flu.  This year, it is particularly important that pregnant women take up the offer of the free flu vaccine, which is safe in all trimesters of pregnancy, to protect them from becoming seriously unwell with flu.

“The findings of this paper highlight the need for more research into the effects of the virus on pregnant women and their babies in order for health services to better respond to their needs during this time.

“The RCOG is committed to supporting the delivery of high-quality women’s healthcare, during and beyond the COVID-19 pandemic.”

Prof Marian Knight, Professor of Maternal and Child Population Health, Nuffield Department of Population Health, University of Oxford, said:

“Reviews such as this can only be as good as the studies they summarise and it is important to note that a high proportion of the included studies have a substantial risk of bias.  Many studies are from single hospitals and it is unclear whether the information reported includes all affected pregnant women, or only a subset.  Importantly, the reported findings concerning intensive care largely come from a single study from a large US dataset which has information on pregnancy status for only 28% of women included.  There is thus a high risk of misclassification.  Comparing findings from two UK studies, both published earlier in the year in the BMJ does not suggest that pregnant women with COVID-19 in the UK are at higher risk of intensive care admission or of dying compared with non-pregnant women with COVID-19.

“It is also important to recognise that, whilst this review reports high preterm birth rates, a number of women affected by COVID-19 in pregnancy are still pregnant, and thus are not included in the study data.  This may make preterm birth rates appear artificially high.  Preterm birth rates are likely to be lower once all women have given birth and their information is included.  Nevertheless, some pregnant women affected by COVID-19 may have a subsequent preterm birth and preventing infection remains essential.  Pregnant women should thus continue to pay attention to hand washing and social distancing measures to reduce their risk of coronavirus.”

Prof Andrew Shennan, Professor of Obstetrics, King’s College London, said:

“This is a large, well conducted summary of the evidence concerning the effects of COVID19 in pregnancy.  It includes 77 studieds in over 11000 women.

“It confirms that COVID19 is not serious for the vast majority of women in pregnancy.  Only 1 in 1000 affected women died and this is likely to be an overestimate, as this data tends to report higher risk women and includes deaths from causes other than COVID-19.

“Early labour is also not increased but early delivery to help manage the sick woman maybe needed.  Pregnant women are slightly more likely to be admitted to intensive care.

“Like non-pregnant individuals, age, weight, high blood pressure and diabetes are significant risk factors.  Pregnant women were less likely to have high temperature and muscle pains, possibly because they are routinely tested rather than present with symptoms.”

Dr Edward Mullins, NIHR Academic Clinical Lecturer, Imperial College, said:

“This living systematic review is a useful resource for the healthcare community.  The review’s findings confirm the increased risk of pre-term delivery, but not spontaneous pre-term labour with SARS-CoV-2 infection and that women in pregnancy have comparable outcomes to women who are not pregnant – which is different to the worse outcomes seen in women in pregnancy with other pandemic respiratory viruses.

“The findings of the review support ongoing social distancing measures for women in the latter stages of pregnancy to reduce the risk of pre-term delivery.  There are unanswered questions on the impact of SARS-CoV-2 infection in early pregnancy and on transmission from mother to baby in the womb which need to be addressed to further understand how this virus affects women in pregnancy.

“The study used robust methodology to identify all relevant studies and minimise duplication of women included.  Its limitation is in the relatively low number of women in pregnancy with some of the reported outcomes, which will increase over time.”

‘Clinical manifestations, risk factors, and maternal and perinatal outcomes of coronavirus disease 2019 in pregnancy: living systematic review and meta-analysis’ by John Allotey et al. was published in the BMJ at 23:30 UK time on Tuesday 1 September 2020.

DOI: 10.1136/bmj.m3320

Declared interests

Prof Marian Knight: “I run national surveillance of COVID-19 in pregnancy in the UK and was an advisor to the systematic review group.”

Prof Andrew Shennan: “I have no conflicts with this subject matter.”

Prof Edward Mullins: “I run a global registry of pregnancy and COVID-19 (PAN-COVID) funded by NIHR.”

None others received.