Evaluation of preterm births and birth defects in liveborn infants of US military women who received smallpox vaccine.
BACKGROUND
Women serving in the US military have some unique occupational exposures, including exposure to vaccinations that are rarely required in civilian professions. When vaccinations are inadvertently given during pregnancy, such exposures raise special concerns. These analyses address health outcomes, particularly preterm births and birth defects, among infants who appear to have been exposed to maternal smallpox vaccination in pregnancy.


METHODS
This retrospective cohort study included 31,420 infants born to active-duty military women during 2003-2004. We used Department of Defense databases to define maternal vaccination and infant health outcomes. Multivariable regression models were developed to describe associations between maternal smallpox vaccination and preterm births and birth defects in liveborn infants.


RESULTS
There were 7,735 infants identified as born to women ever vaccinated against smallpox, and 672 infants born to women vaccinated in the first trimester of pregnancy. In multivariable modeling, maternal smallpox vaccination in pregnancy was not associated with preterm or extreme preterm delivery. Maternal smallpox vaccination in the first trimester of pregnancy was not significantly associated with overall birth defects (OR 1.40; 95% CI: 0.94, 2.07), or any of seven specific defects individually modeled.


CONCLUSIONS
Results may be reassuring that smallpox vaccine, when inadvertently administered to pregnant women, is not associated with preterm delivery or birth defects in liveborn infants.
Ryan
Margaret A K
MA
US Department of Defense Center for Deployment Health Research, Naval Health Research Center, San Diego, California 92106, USA.
Gumbs
Gia R
GR
Conlin
Ava Marie S
AM
Sevick
Carter J
CJ
Jacobson
Isabel G
IG
Snell
Katherine J
KJ
Spooner
Christina N
CN
Smith
Tyler C
TC
D000328:Adult; D000013:Congenital Abnormalities / Q000453:epidemiology*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D016015:Logistic Models; D008889:Military Personnel / Q000706:statistics & numerical data*; D016017:Odds Ratio; D011159:Population Surveillance; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D047928:Premature Birth / Q000453:epidemiology*; D012900:Smallpox Vaccine / Q000008:administration & dosage / Q000009:adverse effects*; D014611:Vaccination / Q000009:adverse effects*; D014615:Vaccinia / Q000517:prevention & control*; D014930:Women
D012900:Smallpox Vaccine