Vaccination against human papillomavirus – an impact on preterm delivery? Estimations based on literature review

Abstract

Cervical cone excision increases the risk of preterm deliveries. Vaccination against human papillomavirus 16/18 (HPV16/18) will probably prevent development of high grade cervical intraepithelial neoplasia and thereby reduce the need for cervical cone excisions. An HPV16/18 vaccination programme may therefore also prevent some preterm deliveries. We identified the parameters influencing the effect of a HPV16/18 vaccination programme on preterm deliveries, and estimated a possible range of preventable deliveries before the 37th week of pregnancy. The number of preterm deliveries prevented by HPV16/18 vaccination programme would depend on the number of preterm deliveries related to cervical cone excision (extent of the health problem), and the proportion of this health problem that could be prevented by a vaccination programme. We obtained values on the parameters used in the estimations from the scientific literature. If 2% of childbearing women are treated with cervical cone excision, between 60 and 220 preterm deliveries/100 000 births may be related to such treatment. Close to 60% (between 35 and 128 preterm deliveries) could be prevented by an HPV16/18 vaccination programme, if the programme coverage was 90%. If 4% of women are treated with cone excision, between 70 and 257 preterm deliveries/100 000 births could be prevented. HPV16/18 vaccination programmes may reduce the number of preterm deliveries through reducing the need for cone excision.