Introduction: Evidence about COVID-19 and pregnancy has rapidly increased since December 2019, making it difficult to make rigorous evidence-based decisions. The objective of this overview of systematic reviews is to conduct a comprehensive analysis of the current evidence on prognosis of COVID-19 in pregnant women.
Material and methods: We used Living OVerview of Evidence (L·OVE) platform for COVID-19, which continually retrieves studies from 46 data sources (including Pubmed/MEDLINE, Embase, other electronic databases, clinical trials registries, preprint repositories, among other sources relevant to COVID-19), mapping them into PICO questions. The search covered the period from the inception date of each database to September 13, 2020. We included systematic reviews assessing outcomes of pregnant women with COVID-19 and/or their newborns. Two authors independently screened the titles and abstracts, assessed full-texts to select the studies that met the inclusion criteria, extracted data, and appraised the risk of bias of each included systematic review. We measured the overlap of primary studies included among the selected systematic reviews by building a matrix of evidence, calculating the corrected covered area, and assessing the level of overlapping for every pair of systematic reviews.
Results: Our search yielded 1132 references. 52 systematic reviews met inclusion criteria and were included in this overview. Only one review had a low risk of bias, three had an unclear risk of bias, and 48 had a high risk of bias. Most of the included reviews were highly overlapped among each other. In the included reviews, rates of maternal death varied from 0% to 11.1%, admission to intensive care from 2.1% to 28.5%, preterm deliveries before 37 weeks from 14.3% to 61.2%, and cesarean delivery from 48.3% to 100%. Regarding neonatal outcomes, neonatal death varied from 0% to 11.7% while the estimated infection status of the newborn varied between 0% and 11.5%.
Conclusions: Only one of 52 systematic reviews had a low risk of bias. Results were heterogenous and the overlap of primary studies was frequently very high between pairs of systematic reviews. High quality evidence syntheses of comparative studies are needed to guide future clinical decisions.