COVID-19 risks to pregnant women and their babies outlined in global research review

Pregnant women with COVID-19 are at increased risk of severe COVID-19, particularly if they are from ethnic minority backgrounds, or if they have pre-existing conditions like obesity, high blood pressure and diabetes, concludes the research led by the University of Birmingham and World Health Organization (WHO).

Their research, published today (March 11) in the BMJ, is part of a unique and ongoing living systematic review and meta-analysis of data, which began in April 2020, and follows the researchers' first publication in the BMJ last August.

This latest publication details the researchers' analysis of the results of 192 studies -- an additional 115 studies than were included in their August publication -- into the impact of COVID-19 on pregnant women and their babies.

The review found that one in 10 pregnant and recently pregnant women attending or admitted to hospital for any reason were diagnosed with confirmed COVID-19. Overall, 339 pregnant women with confirmed COVID-19 died from any cause (0.02% of a total 41,664 women involved in 59 studies). The overall rates of stillbirth and neonatal death are low in women with suspected or confirmed COVID-19, the review found.

The most common clinical symptoms of COVID-19 in pregnant women were fever (40%) and cough (41%), although compared to non-pregnant women of reproductive age, pregnant and recently pregnant women with COVID-19 were more likely to by asymptomatic.

Increased maternal age, high body mass index, non-white ethnicity, and pre-existing comorbidity including chronic hypertension and diabetes were identified as risk factors for pregnant women developing severe COVID-19. While there is emerging evidence from the review that pregnancy specific conditions such as pre-eclampsia and gestational diabetes may be associated with severe covid-19, the authors state that more data are needed to robustly assess the association between pregnancy specific risk factors and COVID-19 related outcomes.

First Author Dr John Allotey, of the University of Birmingham-based WHO Collaborating Centre for Global Women's Health, said: "Pregnant women should be considered a high risk group, particularly those identified to have risk factors, for severe COVID-19 based on our findings. Mothers should also be reassured that the risks to their babies is very low."

Professor Shakila Thangaratinam, corresponding author and Co-Director of the WHO Collaborating Centre for Global Women's Health at the University of Birmingham, added: "In the current situation, where evidence is rapidly produced, our living systematic review -- underpinned by robust methods and continually updated at regular intervals -- is crucial to address important research questions and to shape healthcare policy and clinical decision-making.

"Pregnant women and healthcare professionals will need to take into account the additional risks faced by pregnant women with COVID-19 in making decisions such as taking-up of vaccines if offered to prevent COVID-19, and plan management in pregnancy."