Susan E. Yuill (Australia)
Cancer Council NSW Cancer Research DivisionPresenter of 2 Presentations
PREDICTED IMPACT OF HPV VACCINATION AND PRIMARY HPV SCREENING ON ADVERSE PREGNANCY OUTCOMES IN AUSTRALIA 2005-2070: MODELLING IN A HIGH INCOME, HIGH VACCINATION COVERAGE COUNTRY (ID 710)
Webcast
HAS HPV VACCINATION PREVENTED ADVERSE PREGNANCY OUTCOMES? POPULATION LEVEL ANALYSIS AFTER EIGHT YEARS OF A NATIONAL HPV VACCINATION PROGRAM IN AUSTRALIA (ID 696)
Abstract
Introduction
HPV infection, and its sequelae of precancerous cervical lesions and their subsequent treatment, have been linked with an increased risk of adverse pregnancy outcomes (APOs), including an increased risk of preterm births (PTBs) and small for gestational age (SGA) infants. Publicly-funded HPV vaccination of adolescent females commenced in Australia in 2007 with initial catch-up to age 26 years. Vaccination has been shown to reduce rates of HPV infections, anogenital warts, and cervical precancerous lesions.
Methods
Using aggregated data from the Australian Institute of Health and Welfare National Perinatal Data Collection, we compared rates of PTBs and SGA infants born in Australia between 2000 and 2015. We used generalised linear models (GLMs), assuming a Poisson distribution and log link function, with single-year categories of infant birth year, maternal age, and age-year-specific HPV vaccination coverage as independent variables.
Results
For every 20% increase in HPV vaccination coverage in the maternal cohort, there was a relative incidence rate reduction of 1.0% (95%CI: 0.4%-1.5%) for PTBs and 1.8% (95%CI: 1.2%-2.4%) for SGA births, after adjusting for infant’s birth year and maternal age. In the maternal cohorts with 60-80% HPV vaccination coverage achieved in Australia, the vaccination program within this period is estimated to have resulted in a reduction of 3.2% (95%CI: 1.1%-5.3%) in PTB and 9.8% (95%CI: 8.2%-11.4%) in SGA infants. We estimated that about 370 PTBs and over 1000 SGA births may have been prevented in Australia in 2015.
Conclusions
Although data were aggregated and we were unable to fully adjust for potential confounding by smoking behaviour and other factors, this study provides preliminary population-level evidence of a reduction in APOs in cohorts of women who have been offered HPV vaccination. These findings from Australia, the first country to introduce HPV vaccination, indicate broader benefits than have been documented to date.