Covid-19 in Pregnancy: a French Population-based Cohort of Women and Newborns

In the overall context of uncertainty about the morbidity associated with COVID-19 infection and its optimal management, knowledge is urgently required on infection during pregnancy.

First, pregnant women and newborns can have specific and severe reactions to infectious diseases, as seen in previous pandemics which justifies targeted surveillance. Second, optimal management must minimize the health risks of transmission to the newborn. While initial studies did not provide evidence for transmission in utero or during delivery, more recent data suggest that transmission is possible. The virus is present in vaginal secretions and stool, making vertical contamination possible during vaginal delivery. Similarly, transmission may occur during breastfeeding. These risks, which remain theoretical, must be weighed against known harmful consequences of mitigating strategies such as systematic caesarean (increase in maternal morbidity) and separating the child from the mother and contraindicating breastfeeding (negative impact on maternal-child bonding and optimal nutrition). In the absence of reliable data, some maternity hospitals have adopted a maximum precautionary principle, recommending caesarean for all COVID-19 positive women and imposing immediate mother-child separation after childbirth. These approaches are strongly debated in France. Third, optimal management of COVID-19 during pregnancy requires balancing maternal and newborn risks. Risks of maternal deterioration in the event of continuing pregnancy must be weighed against those to the child resulting from indicated preterm birth. This tradeoff is even more complex as evidence-based interventions to protect preterm infants, such as antenatal corticosteroid, may aggravate maternal infection. Finally, childbirth is not an elective procedure and requires managing large numbers of healthy women and newborns in a hospital setting where they are exposed to risks of infection.

Population-based research that captures the diversity of organizational structures and practices within maternity units is needed to guide management during the current epidemic and draw lessons for future infectious pandemics.

Principal innovative features are:

• A population-based approach: Current data systems will include a limited number of pregnant women, principally from university hospitals with specific patient populations and management strategies. Because all maternity hospitals care for COVID-19+ pregnant women, a population-based approach is needed to calculate reliable incidence rates, assess practice variability and measure the impact of differences in management on maternal and newborn infection rates and health.
• The inclusion of infected pregnant women who are not hospitalized and who recover before delivery will provide comprehensive data and measure early fetal in-utero exposure.
• Immediate feedback to clinicians on their practices will inform current controversies about optimal management.
• Joint follow-up of mother and child to 12 weeks after delivery, and longer if indicated, will document the medium-term impact of infection.
• Inclusion of regions with time-varying exposure to the epidemic will provide information to evaluate public health policies.