Table 2.

Incidence Rates and Adjusted Incidence Rate Ratios For Adverse Obstetric Events Occurring Within 42 Days of Receiving Trivalent Inactivated Influenza Vaccine

Outcome	42-Day Events Number of events (Rates per 1000 pregnancies)			Multivariable Analyses*
	Vaccinated	Unvaccinated	P	Adjusted Incidence Rate Ratio (95% CI)	P
Vaccinated in first trimester	n=21,107	n=40,738
Hyperemesis	427 (20.2)	907 (22.3)	.10	.88 (.79–0.99)	.03
Chronic hypertension †‡	11 (.5)	30 (.7)	.32	.67 (0.34–1.34)	.26
Vaccinated at 20 weeks or greater	n=38,038	n=74,192
Gestational hypertension†‡	504 (13.2)	973 (13.1)	.85	.99 (.89–1.11)	.89
Gestational diabetes‡	868 (22.8)	1908 (25.7)	.003	.89 (.82–.96)	.004
Vaccinated in any trimester	n=74,292	n=144,597
Proteinuria†	58 (.80)	153 (1.1)	.048	.73 (.54–.99)	.04
Urinary tract infection	609 (8.2)	1305 (9.0)	.049	.92 (.84–1.02)	.10

CI, confidence interval.

^*All outcomes adjusted for receipt of medical care in the first trimester, hospitalization prior to vaccination or index date, and poverty; additional adjustments were outcome specific

^†Also adjusted for diabetes, gestational diabetes

^‡Also adjusted for obesity