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

Immunization Safety Office, Division of Healthcare Quality Promotion, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA.
American journal of obstetrics and gynecology (Impact Factor: 4.7). 06/2011; 205(5):473.e1-9. DOI: 10.1016/j.ajog.2011.06.047
Source: PubMed


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.
We reviewed reports of adverse events (AEs) in pregnant women who received 2009-H1N1 vaccines from Oct. 1, 2009, through Feb. 28, 2010.
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.
Review of reports to VAERS following H1N1 vaccination in pregnant women did not identify any concerning patterns of maternal or fetal outcomes.

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Available from: Pedro L Moro, Dec 24, 2013
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    • "Studies of over 1000 women from Italy, France, Scotland, and the United Kingdom reported no serious adverse events among pregnant women or their neonates, with no significant differences in adverse birth outcomes and congenital anomaly rates compared with the background rates in the general population.53–56 A published review of reports to VAERS also concluded that there was no concerning pattern of maternal or fetal outcomes among women who were vaccinated during pregnancy or their children.57 "
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    • "In fact, because of potential impact on the fetus, in our specialty, safety concerns can be amplified both for patients and providers for immunizations recommend during pregnancy [5–7]. We have seen that data generated from VAERS is able to reinforce the safety profile for recommending vaccines during pregnancy, including H1N1 and Tdap [8–10]. With increased reporting to VAERS, the data base will become more robust. "
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