Adverse events following administration to pregnant women of influenza A (H1N1) 2009 monovalent vaccine reported to the Vaccine Adverse Event Reporting System

Am J Obstet Gynecol. 2011 Nov;205(5):473.e1-9. doi: 10.1016/j.ajog.2011.06.047. Epub 2011 Jun 21.

Abstract

Objective: The objective of the study was to evaluate and summarize reports to the Vaccine Adverse Event Reporting System (VAERS), a spontaneous reporting system, in pregnant women who received influenza A (H1N1) 2009 monovalent vaccine to assess for potential vaccine safety problems.

Study design: We reviewed reports of adverse events (AEs) in pregnant women who received 2009-H1N1 vaccines from Oct. 1, 2009, through Feb. 28, 2010.

Results: VAERS received 294 reports of AEs in pregnant women who received 2009-H1N1 vaccine: 288 after inactivated and 6 after the live attenuated vaccines. Two maternal deaths were reported. Fifty-nine women (20.1%) were hospitalized. We verified 131 pregnancy-specific outcomes: 95 spontaneous abortions (<20 weeks); 18 stillbirths (≥20 weeks); 7 preterm deliveries (<37 weeks); 3 threatened abortions; 2 preterm labor; 2 preeclampsia; and 1 each of fetal hydronephrosis, fetal tachycardia, intrauterine growth retardation, and cleft lip.

Conclusion: Review of reports to VAERS following H1N1 vaccination in pregnant women did not identify any concerning patterns of maternal or fetal outcomes.

MeSH terms

  • Adverse Drug Reaction Reporting Systems
  • Female
  • Humans
  • Influenza A Virus, H1N1 Subtype / immunology*
  • Influenza Vaccines / adverse effects*
  • Influenza, Human / immunology
  • Influenza, Human / prevention & control*
  • Patient Safety
  • Pregnancy
  • Vaccines, Attenuated / adverse effects

Substances

  • Influenza Vaccines
  • Vaccines, Attenuated