HPV vaccine and pregnancy

A pooled analysis of five randomised phase III trials of Merck’s quadrivalent human papillomavirus vaccine Gardasil has found no evidence of an increased risk of neonatal complications (Obstet Gynecol 2009;114:1179–88).

Of 20 551 trial participants, pregnancy was reported in 1796 women exposed to the vaccine and 1824 assigned to receive placebo. There were no significant differences in the incidence of live births, fetal loss or spontaneous abortion. A diverse range of congenital anomalies consistent with patterns in the general population was reported in 40 children born to vaccinated women and 30 born to women given placebo; this difference was not statistically significant.

Supporting evidence comes from a smaller analysis of Merck’s postmarketing data, in which 517 pregnancies with known outcome were recorded (Obstet Gynecol 2009;114:1170–78). There were 451 (87 per cent) live births and 454 neonates, of whom 97 per cent had no anomalies. The prevalence of major birth defects among live born infants was 2.2 per cent. The overall rate of spontaneous abortion was 6.9 per cent. There were seven fetal deaths (1.5 per cent).