As per the outcomes of a novel study issued in PloS One, preterm birth and severe COVID-19 share some mutual risk factors, i.e., body mass index (BMI) more than 24.9, chronic hypertension, or high blood pressure, asthma, which may imply a high rate of indicated preterm birth due to maternal conditions. This real-world, case-control study studied the effect of asymptomatic or mild COVID infection on preterm birth not because of maternal respiratory failure.

Women admitted to the hospital from 20 September 2020 to 9 January 2021 were considered. The occurrence of SARS-CoV-2 was compared between preterm birth (known as the case group comprising of 102 women) and full-term delivery (known as the control group comprising of 127 women) on an aggregate. Just the women with spontaneous or medically-indicated preterm birth due to fetal vascular malperfusion (pregnancy-associated high blood pressure and its problems) were counted in.

History of COVID infection or existing infection was determined via nasopharyngeal swab testing and the presence of IgM/IgG antibodies in the blood samples. No profound difference was witnessed between the groups. However, the case group was saddled by a higher rate of 3 known risk factors (i.e. BMI > 24.9, asthma, chronic high blood pressure or hypertension) for severe COVID disease.

Asymptomatic or mild SARS-CoV-2 was not found to be an independent predictor of the indicated preterm birth. Therefore, mild or asymptomatic SARS-CoV-2 infection does not elevate the risk of preterm delivery in pregnant women.