Vaccine, Poliovirus Inactivated in Pregnancy and Breastfeeding
Fetal Risk Summary
Poliovirus vaccine inactivated (Salk vaccine, IPV) is an inactivated virus vaccine administered by injection (1,2). Animal reproduction studies have not been conducted with the vaccine.
Although fetal damage may occur when the mother contracts the disease during pregnancy, the risk to the fetus from the vaccine is unknown (1). No adverse effects attributable to the use of the inactivated vaccine have been reported (2,3). Both the American College of Obstetricians and Gynecologists and the Immunization Practices Advisory Committee (ACIP) recommend use of the vaccine during pregnancy only if an increased risk of exposure exists (1,3). If immediate protection against poliomyelitis is needed, the ACIP states that either the inactivated or oral vaccine may be used in accordance with the recommended schedules for adults (see Reference for specific details) (3). The inactivated vaccine, however, was preferred over the oral form because of a lower risk of vaccine-associated paralysis.
The Collaborative Perinatal Project monitored 50,282 mother-child pairs, 6,774 of whom had 1st-trimester exposure to the vaccine (4, p. 315). Congenital malformations were observed in 461 (standardized relative risk [SRR] 1.03). In general, no associations (SRR >1.5) were found (4, p. 318). Specific malformations with SRR >1.5 were: craniosynostosis, 6 (SRR 2.1); atrial septal defect, 6 (SRR 4.0); cleft lip with or without cleft palate, 9 (SRR 1.6); omphalocele, 5 (SRR 2.4); and any malignant tumors, 7 (SRR 3.3) (4, pp. 473474). For use anytime in pregnancy, 18,219 mother-child pairs were exposed (4, p. 436). A total of 374 newborns had anomalies (SRR 1.08). Specific malformations with SRR >1.5 were: hypoplasia of limb or part thereof, 24 (SRR 1.6); malformations of thoracic wall, 9 (SRR 2.4); anomalies of the teeth, 8 (SRR 2.0); corneal opacity, 5 (SRR 3.5); and central nervous system tumors, 7 (SRR 17.9) (4, pp. 486487). The authors of this study cautioned that these data are uninterpretable without independent confirmation from other studies and that any positive or negative association may have occurred by chance (4).
Breast Feeding Summary
No data are available.
- American College of Obstetricians and Gynecologists. Immunization during pregnancy. Technical Bulletin. No. 160, October 1991.
- Linder N, Ohel G. In utero vaccination. Clin Perinatol 1994;21:66374.
- Centers for Disease Control and Prevention. Poliomyelitis prevention in the United States: introduction of a sequential vaccination schedule of inactivated poliovirus vaccine followed by oral poliovirus vaccine. Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR 1997;46(No. RR-3):125.
Heinonen OP, Slone D, Shapiro S. Birth Defects and Drugs in Pregnancy. Littleton, MA: Publishing Sciences Group, 1977.