A new meta-analysis of 11 studies reveals a 3.4% estimated prevalence of respiratory syncytial virus (RSV) infection during pregnancy, but with a wide range in estimates, according to a study published yesterday in The Journal of Infectious Diseases.
The analysis comes during a year in which RSV has been the target of new vaccines and monoclonal antibody therapies. Though a mild respiratory illness in most adults, the virus can be severe in infants under 6 months of age, the elderly, and pregnant women.
The meta-analysis, which looked for studies of reparatory illnesses in pregnancy, included 11 studies with pregnant women recruited from 2010 to 2022, for a total of 8,126 patients.
The proportion of pregnant women with respiratory infections who tested positive for RSV ranged from 0.9% in a study in South Africa to 10.7% in a study conducted in Thailand, with a meta-estimate of 3.4% (95% confidence interval [CI], 1.9% to 54%).
Few hospitalizations, no deaths
The estimated incidence rate of prenatal RSV infection was 2.1 (95% CI, 1.3 to 3.0) per 1,000 person-months or 26.0 (95% CI, 15.8 to 36.2) per 1,000 person-years, the authors said.
Hospitalizations were uncommon, and no RSV-associated deaths were observed.
“Hospitalizations were uncommon, and no RSV-associated deaths were observed. Based on limited data from three studies, the odds of stillbirths, miscarriage, low birth weight, and small for gestational age did not differ between pregnant individuals who had antenatal RSV infection compared to those who did not,” the authors wrote.
Some studies, however, showed increased odds of preterm delivery in pregnancies affected by RSV (3.6; 95% CI, 1.3 to 10.3).
More studies should be conducted, the authors said, especially as maternal RSV vaccines are rolled out later this year.