Long COVID After Acquisition of the Omicron Variant of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) During Pregnancy Compared With Outside of Pregnancy
COVID-19 infection during pregnancy did not increase long COVID risk compared with infection outside pregnancy.
*Multicenter observational cohort; Level 2 (OCEBM).
Citation
Metz TD, Reeder HT, Clifton RG, et al. Long COVID After Acquisition of the Omicron Variant of Severe Acute Respiratory Syndrome Coronavirus 2 During Pregnancy Compared With Outside of Pregnancy. Obstetrics & Gynecology. 2026;147(3):404-414. doi:10.1097/AOG.0000000000006067
Background
Long COVID can cause lasting symptoms after COVID-19 infection. Pregnancy changes immune and hormone function, so it was unclear whether infection during pregnancy changes later long COVID risk.
Patients
Adults assigned female at birth, aged 18 to 45 years, with a first COVID-19 infection on or after December 1, 2021, enrolled at 79 United States sites. Exclusions included unknown pregnancy status at infection and enrollment more than 4.5 months after infection.
Intervention
COVID-19 infection during pregnancy, at any gestational age.
Control
COVID-19 infection outside pregnancy in similar-aged individuals.
Outcome
Long COVID at 6 months, defined by the RECOVER Adult Long COVID Research Index score (0 to 30; 11 or higher classified as long COVID).
Follow-up Period
Primary: 6 months. Secondary: 9 and 12 months.
Results
The study included 2,423 participants; 580 were pregnant at infection. Most participants with known vaccination status were fully vaccinated.
After adjustment, long COVID at 6 months occurred in 10.2% of those infected during pregnancy and 10.6% of those infected outside pregnancy. There was no significant difference in risk: adjusted risk ratio 0.96, 95% confidence interval 0.63 to 1.48.
Findings were similar at 9 months and 12 months. Among participants with long COVID, chronic cough, shortness of breath, and thirst were more common after infection during pregnancy, while brain fog, worsening symptoms after activity, and chest pain were more common after infection outside pregnancy.
No established patient-centered minimally important difference exists for the research index used.
Limitations
Observational design limits causal conclusions. Results mainly apply to the Omicron era and a highly vaccinated cohort. About one quarter lacked the 6-month symptom score. Most pregnancies ended in live birth, limiting conclusions after pregnancy loss. The research score may not match clinical diagnosis in all patients.
Funding
United States National Institutes of Health; funder had no study role.
Clinical Application
Pregnancy alone should not change long COVID counseling after Omicron-era infection; evaluate persistent postpartum symptoms as possible long COVID.
Discussion
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In this multicenter observational cohort, SARS-CoV-2 acquisition during pregnancy was not associated with long COVID at 6 months (adjusted RR 0.96, 95% CI 0.63–1.48); given propensity matching but nonrandomized design, how valid and applicable are these findings for counseling pregnant patients? In this observational cohort, the adjusted risk ratio for long COVID at 6 months among participants infected during pregnancy versus outside pregnancy was 0.96 with a 95% CI of 0.63–1.48. What is the best interpretation of this result?