SARS-CoV-2 During Pregnancy—Emerging Evidence of Uncommon Complications

By
George L. Anesi
Arturo Casadevall
May 7, 2026

Jama Network Open

Overview

Revise to emphasize the lack of statistical significance and its implications for vaccination strategies.

Background

Expand on the inconclusive evidence regarding congenital anomalies and the biological plausibility.

Data Highlights

Outcome	Maternal SARS-CoV-2 Cohort	Uninfected Cohort	Rate Ratio (95% CI)
Any Congenital Anomaly	32.5 per 1000 live births	31.1 per 1000 live births	1.04 (0.87-1.24)
Cardiac Anomalies	10.7 per 1000 live births	8.8 per 1000 live births	1.22 (0.88-1.66)

Key Findings

1.4 additional congenital anomalies per 1000 live births were observed in the maternal SARS-CoV-2 infection cohort.
The rate ratio for any congenital anomaly was 1.04, indicating no statistical significance.
Cardiac anomalies were reported at a rate of 10.7 per 1000 live births in the infected cohort versus 8.8 in the uninfected cohort.
The study utilized a large, diverse population sample from Ontario, Canada.
Exclusion of stillbirths may bias results toward the null regarding congenital anomalies.
Statistical significance was not achieved despite trends suggesting potential harm associated with maternal SARS-CoV-2 infection.

Clinical Implications

Healthcare providers should remain vigilant regarding the potential risks associated with maternal SARS-CoV-2 infection, particularly concerning congenital anomalies. Vaccination against COVID-19 in pregnant individuals is strongly recommended to mitigate risks of severe illness and potential adverse outcomes. Clinicians should also consider the implications of asymptomatic infections when interpreting study results.