COVID-19 and pregnancy: An umbrella review of clinical presentation, vertical transmission, and maternal and perinatal outcomes

Abstract

Background We conducted an overview of systematic reviews (SRs) summarizing the best evidence regarding the effect of COVID-19 on maternal and child health following Cochrane methods and PRISMA statement for reporting (PROSPERO-CRD42020208783). Methods We searched literature databases and COVID-19 research websites from January to October 2020. We selected relevant SRs reporting adequate search strategy, data synthesis, risk of bias assessment, and/or individual description of included studies describing COVID-19 and pregnancy outcomes. Pair of reviewers independently selected studies through COVIDENCE web-software, performed the data extraction, and assessed its quality through the AMSTAR-2 tool. Discrepancies were resolved by consensus. Each SR’s results were synthesized and for the most recent, relevant, comprehensive, and with the highest quality, by predefined criteria, we presented GRADE evidence tables. Results We included 66 SRs of observational studies out of 608 references retrieved and most (61/66) had "critically low" overall quality. We found a relatively low degree of primary study overlap across SRs. The most frequent COVID-19 clinical findings during pregnancy were fever (28–100%), mild respiratory symptoms (20–79%), raised C-reactive protein (28–96%), lymphopenia (34–80%), and pneumonia signs in diagnostic imaging (7–99%). The most frequent maternal outcomes were C-section (23–96%) and preterm delivery (14–64%). Most of their babies were asymptomatic (16–93%) or presented fever (0–50%), low birth weight (5–43%) or preterm delivery (2–69%). The odds ratio (OR) of receiving invasive ventilation for COVID-19 versus non-COVID-19 pregnant women was 1.88 (95% Confidence Interval [CI] 1.36–2.60) and the OR that their babies were admitted to neonatal intensive care unit was 3.13 (95%CI 2.05–4.78). The risk of congenital transmission or via breast milk was estimated to be low, but close contacts may carry risks. Conclusion This comprehensive overview supports that pregnant women with COVID-19 may be at increased risk of adverse pregnancy and birth outcomes and low risk of congenital transmission.

Perinatal COVID-19

“…A high rate of asymptomatic infection among pregnant women with COVID-19 has been demonstrated wherever universal perinatal screening has been implemented. 1 …”

“… 2 , 3 Additionally, older age, higher body mass index and pre-existing comorbidities, mainly diabetes, hypertension and lung disease, seem to predispose to severe COVID-19 during pregnancy. 1 , 3…”

“…Nationwide lockdowns, disruption of health-care services and fear of attending health-care facilities might have affected the wellbeing of pregnant women and their babies, probably accounting, for instance, for the substantial increase of stillbirths observed in a few studies during the pandemic. 1 , 2 …”

“… 7 When it occurs, it seems that neonatal COVID-19 is largely horizontally acquired during postnatal period due to close contact by droplet or airborne transmission. 1 , 5 Vertical transmission from mother to infant does not seem common but remains possible based on available reporting. 1 Moreover, the risk of transmission via breast milk is estimated to be low to very low.…”

“… 1 , 5 Vertical transmission from mother to infant does not seem common but remains possible based on available reporting. 1 Moreover, the risk of transmission via breast milk is estimated to be low to very low. 1 …”