Risk of pregnancy among adolescent schoolgirls participating in a measles mass immunization program.

A large measles vaccination program in the Albuquerque, New Mexico public schools in 1981, conducted according to US Public Health Service guidelines, was studied to determine rates of pregnancy among adolescent vaccinees. Pre-vaccination counseling of 1,922 clinic attendees prevented seven pregnant girls from being vaccinated. Despite counseling, of 1,913 female vaccinees age 13-18 years old, two were pregnant at the time of vaccination (1.05 pregnancies per 1,000 vaccinees) and an additional four girls became pregnant in the three months after vaccination (2.1 pregnancies per 1,000 vaccinees). Data supporting low or absent fetal risks from measles and rubella vaccine, combined with the low pregnancy rate among vaccinees documented in this study, support the reasonableness of the recommended strategy for measles and rubella vaccination of secondary schoolgirls.