Pregnant women are not at greater risk of severe COVID-19 than other women | University of Oxford

Pregnant women are not at greater risk of severe COVID-19 than other women

11 May 2020

  • 4.9 pregnant women per 1000 were admitted to hospital in the UK with COVID-19, around 1 in 10 of whom received intensive care, suggesting that pregnant woman are at no greater risk of severe illness than the non-pregnant population.
  • Pregnant women from black and other minority ethnic groups were more likely to be admitted to hospital with COVID-19.
  • Older pregnant women, those who were overweight or obese, and pregnant women with pre-existing conditions such as high blood pressure and diabetes were also more likely to be admitted to hospital.

Researchers from the University of Oxford, in collaboration with the Royal College of Obstetricians and Gynaecologists, the Universities of Leeds and Birmingham, Kings and Imperial Colleges London, have published new research that suggests pregnant women are no more likely to become ill with severe COVID-19 than non-pregnant woman. However, the majority of women who did become severely ill were in their third trimester of pregnancy, emphasising the importance of social distancing for this group.

The study, published today as a pre-print, looked at 427 pregnant women admitted to hospitals in the UK between 1 March and 14 April 2020 with confirmed COVID-19 (4.9 women out of every 1000 pregnant women, suggesting pregnant women are not at a higher risk of experiencing severe illness). Information for the study was collected from all 194 hospitals in the UK with a consultant-led maternity unit.

Pregnant women from black and ethnic minority backgrounds were more likely to be admitted to hospital for COVID-19. This inequality persisted even when women from London, the West Midlands and the North West were excluded from the analysis, meaning the difference cannot be explained by higher rates of COVID-19 infection in those areas.

The analysis also showed that older pregnant women, those who were overweight or obese, and pregnant women who had pre-existing medical problems, such as high blood pressure and diabetes, were more likely to be admitted to hospital with the infection. Women who were admitted to hospital with COVID-19 in pregnancy were less likely to smoke than a group of comparison pregnant women.

Other important findings from the study include:

  • One in five babies born to mothers hospitalised with COVID-19 were born pre-mature and were admitted to a neonatal unit
  • One in twenty babies born had a positive test for COVID-19, but only half of them immediately after birth

Sixty percent of the women admitted to hospital have now given birth, while the remaining forty percent have ongoing pregnancies. Most women have now been discharged home. Around one in 10 women required intensive care, and sadly five women have died.

Outcomes for babies born to mothers with COVID-19 were mostly good. Although almost one in five were born prematurely and were admitted to a neonatal unit, fewer than twenty babies were born very premature (when their mothers were less than 32 weeks pregnant). One in twenty babies born had a positive test for COVID-19, but only half of these babies had positive test immediately after birth, suggesting that transmission of infection from mother to baby is low.

Professor Marian Knight, Professor of Maternal and Child Population Health at the Nuffield Department of Population Health, University of Oxford and lead investigator for the study, said: ‘A very small number of pregnant women do become severely ill with COVID-19 and sadly some women have died. Our thoughts must remain with their families. It is concerning that more pregnant women from black and minority ethnic groups are admitted with COVID-19 in pregnancy and this needs urgent investigation.

‘Most pregnant women who were admitted to hospital were more than six months pregnant, which emphasises the importance of continued social distancing measures in the later stages of pregnancy. Following the current guidance about careful social distancing will help prevent infection.’

Edward Morris, President of the Royal College of Obstetricians and Gynaecologists and an author on the study, said: ‘Admission with infection in pregnancy is also associated with older maternal age, overweight and obesity, and the presence of pre-existing medical conditions. Awareness of these factors is important for both women and their doctors and midwives to help ensure women receive appropriate advice about prevention and complications of COVID-19 are recognised early. Detailed advice and guidance for women is available on the RCOG website.’

Gill Walton, Chief Executive of the Royal College of Midwives, said: ‘During this current crisis, pregnancies have continued, babies have been born, and, throughout it all, midwives have been at their side, supporting and caring for them. It’s absolutely vital that women continue to attend antenatal appointments to ensure that they and their babies are well. Staying in touch with their maternity services team will help put any concerns at ease and enable them to act quickly when necessary.’

Information for the study was collected using a research system called the UK Obstetric Surveillance System (UKOSS). The study was funded by the National Institute for Health Research in 2012 in preparation for the possibility of a pandemic, to ensure we could collect accurate information to advise pregnant women, their midwives and doctors. It was activated in March and the information has been being used to guide the ongoing response. This study is one of a number of COVID-19 studies that have been given urgent public health research status by the Chief Medical Officer/ Deputy Chief Medical Officer for England.

For interview requests or a copy of the study, contact:

Notes to editors

About the University of Oxford
Oxford University has been placed number 1 in the Times Higher Education World University Rankings for the third year running, and at the heart of this success is our ground-breaking research and innovation. Oxford is world-famous for research excellence and home to some of the most talented people from across the globe. Our work helps the lives of millions, solving real-world problems through a huge network of partnerships and collaborations. The breadth and interdisciplinary nature of our research sparks imaginative and inventive insights and solutions. Through its research commercialisation arm, Oxford University Innovation, Oxford is the highest university patent filer in the UK and is ranked first in the UK for university spinouts, having created more than 170 new companies since 1988. Over a third of these companies have been created in the past three years.

About the Nuffield Department of Population Health, University of Oxford
The Nuffield Department of Population Health (NDPH) is a world-leading research institute which investigates the causes and prevention of disease. NDPH has over 500 staff working in a number of world-renowned population health research groups, including the Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), the Cancer Epidemiology Unit (CEU), the National Perinatal Epidemiology Unit (NPEU), and other groups working on public health, health economics, ethics, disease prevention, and health record linkage. It is also a key partner in the Oxford University Big Data Institute.

About the Royal College of Obstetricians and Gynaecologists
The Royal College of Obstetricians and Gynaecologists (RCOG) is a medical charity that champions the provision of high quality women’s healthcare in the UK and beyond. It is dedicated to encouraging the study and advancing the science and practice of obstetrics and gynaecology. It does this through postgraduate medical education and training and the publication of clinical guidelines and reports on aspects of the speciality and service provision.

About the Royal College of Midwives
The RCM is the only trade union and professional association dedicated to serving midwifery and the whole midwifery team. We provide workplace advice and support, professional and clinical guidance and information, and learning opportunities with our broad range of events, conferences and online resources. For more information visit the RCM website at https://www.rcm.org.uk/.

About the National Institute of Health Research
Please visit https://www.nihr.ac.uk/covid-19/ to learn about other studies that have been given urgent public health status and the single, national prioritisation process that has been established to prevent duplication of effort and to ensure that the resources and capacity of the health and care system to support COVID-19 research are not exceeded.

The National Institute for Health Research (NIHR) is the nation's largest funder of health and care research. The NIHR:

  • Funds, supports and delivers high quality research that benefits the NHS, public health and social care
  • Engages and involves patients, carers and the public in order to improve the reach, quality and impact of research
  • Attracts, trains and supports the best researchers to tackle the complex health and care challenges of the future
  • Invests in world-class infrastructure and a skilled delivery workforce to translate discoveries into improved treatments and services
  • Partners with other public funders, charities and industry to maximise the value of research to patients and the economy

The NIHR was established in 2006 to improve the health and wealth of the nation through research, and is funded by the Department of Health and Social Care. In addition to its national role, the NIHR commissions applied health research to benefit the poorest people in low- and middle-income countries, using Official Development Assistance funding.