Safety of influenza vaccination during pregnancy.
OBJECTIVE
The purpose of this study was to evaluate the safety of influenza vaccine that is administered in the second or third trimester of gestation.


METHODS
A retrospective electronic database search of 5 influenza seasons (July 1, 1998, to June 30, 2003) was performed at a large multispecialty clinic in Houston, Texas. Immunization rates were calculated, and outcomes of pregnancy were compared between a cohort of healthy women who received influenza vaccine and a control group of healthy unvaccinated women who were matched by age, month of delivery, and type of medical insurance.


RESULTS
Among 7183 eligible mother-infant pairs, only 252 pregnant women (3.5%) received the influenza vaccine. Women with medical insurance were more likely to be vaccinated, although the rates for women with chronic underlying conditions were similar to those of healthy women, regardless of insurance status. The mean gestational age at the time of influenza vaccination was 26.1 weeks (range, 14-39 weeks). No serious adverse events occurred within 42 days of vaccination, and there was no difference between the groups in the outcomes of pregnancy (including cesarean delivery and premature delivery) and infant medical conditions from birth to 6 months of age.


CONCLUSIONS
Influenza vaccine that was administered in the second or third trimester of gestation was safe in this study population.
Munoz
Flor M
FM
Baylor College of Medicine, Department of Pediatrics and Molecular Virology, Houston, TX 77030, USA. florm@bcm.tmc.edu
Greisinger
Anthony J
AJ
Wehmanen
Oscar A
OA
Mouzoon
Melanie E
ME
Hoyle
James C
JC
Smith
Frances A
FA
Glezen
W Paul
WP
D000328:Adult; D016022:Case-Control Studies; D016001:Confidence Intervals; D005069:Evaluation Studies as Topic; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007229:Infant Welfare; D007231:Infant, Newborn; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000009:adverse effects; D007251:Influenza, Human / Q000517:prevention & control*; D008429:Maternal Welfare; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000517:prevention & control*; D011256:Pregnancy Outcome; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D011336:Probability; D012189:Retrospective Studies; D018570:Risk Assessment; D014611:Vaccination / Q000592:standards / Q000639:trends
D007252:Influenza Vaccines