Preterm birth is not associated with asymptomatic/mild SARS-CoV-2 infection per se: pre-pregnancy state is what matters

Cosma, Stefano, University of Turin, https://orcid.org/0000-0003-0563-0071

Carosso, Andrea Roberto, University of Turin

Cusato, Jessica, University of Turin

Borella, Fulvio, University of Turin

Carosso, Marco, University of Turin

Gervasoni, Fiammetta, University of Turin

Stura, Ilaria, University of Turin

Preti, Mario, University of Turin

Ghisetti, Valeria, University of Turin

Di Perri, Giovanni, University of Turin

Benedetto, Chiara, University of Turin

stefano.cosma@unito.it, andrea88.carosso@gmail.com, jessica.cusato@unito.it, fulvio.borella87@gmail.com, marco.carosso94@gmail.com, fiammetta.gervasoni@gmail.com, ilaria.stura@unito.it, mario.preti@unito.it, valeria.ghisetti@gmail.com, giovanni.diperri@unito.it

Published Aug 04, 2021 on Dryad. https://doi.org/10.5061/dryad.9ghx3ffhf

Cite this dataset

Cosma, Stefano et al. (2021). Preterm birth is not associated with asymptomatic/mild SARS-CoV-2 infection per se: pre-pregnancy state is what matters [Dataset]. Dryad. https://doi.org/10.5061/dryad.9ghx3ffhf

Abstract

Evidence for the real impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on preterm birth is unclear, as available series report composite pregnancy outcomes and/or do not stratify patients according to disease severity.The purpose of the research was to determine the real impact of asymptomatic/mild SARS-CoV-2 infection on preterm birth not due to maternal respiratory failure.

This case-control study involved women admitted to a hospital for delivery between 20 September 2020 and 9 January 2021 in northern Italy. The cumulative incidence of Coronavirus disease-19 was compared between preterm birth (case group, n = 102) and full-term delivery (control group, n = 127). Only women with spontaneous or medically-indicated preterm birth because of placental vascular malperfusion (pregnancy-related hypertension and its complications) were included. Current or past SARS-CoV-2 infection was determined by nasopharyngeal swab testing and detection of IgM/IgG antibodies in blood samples. A significant difference in the cumulative incidence of Coronavirus disease-19 between the case (21/102, 20.5%) and the control group (32/127, 25.1%) (P= 0.50) was not observed, although the case group was burdened by a higher prevalence of three known risk factors (body mass index > 24.9, asthma, chronic hypertension) for severe Coronavirus disease-19. Logistic regression analysis showed that asymptomatic/mild SARS-CoV-2 infection was not an independent predictor of spontaneous and medically-indicated preterm birth due to pregnancy-related hypertension and its complications (0.77; 95% confidence interval, 0.41-1.43).

Pregnant patients without comorbidities need to be reassured that asymptomatic/mild SARS-CoV-2 infection does not increase the risk of preterm delivery. Preterm birth and severeCoronavirus disease-19 share common risk factors (i.e., body mass index > 24.9, asthma, chronic hypertension), which may explain the high rate of indicated preterm birth due to maternal conditions reported in the literature.