- Pregnant women with severe influenza during the 2009 H1N1 pandemic were likely to have adverse birth outcomes.
Why this matters
- Influenza vaccination and timely administration of antiviral medications are essential to prevent adverse infant outcomes.
- 490 singleton infants born to mother with confirmed/probable influenza, 1451, 1446 matched by same, prior conception year, respectively.
- Infants born to women with 2009 H1N1 were likelier to be preterm vs prior year (adjusted relative risk [aRR], 1.4; 95% CI, 1.1-1.9), same year (aRR, 1.7; 95% CI, 1.3-2.2) comparisons and have low Apgar scores (aRR, 2.3; 95% CI, 1.2-3.9) vs prior year (aRR, 4.0; 95% CI, 2.1-7.6), same year comparisons.
- Women with severe 2009 H1N1 influenza were likelier to have poor infant outcomes, especially if they were admitted to the ICU (e.g., preterm deliveries [aRR, 3.9; 95% CI, 2.7-5.6], low-birthweight infants [aRR, 4.6; 95% CI, 2.9-7.5], with Apgar scores ≤6 at 5 minutes [aRR, 8.7; 95% CI, 3.6-21.2]), vs same year comparison groups.
- Retrospective matched cohort study linking data on pregnant women with confirmed or probable 2009 H1N1 influenza and their infants to understand influenza effects during pregnancy.
- Funding: CDC.
- Missing maternal confounders.