The association between cervical inflammation and histologic evidence of HPV in PAP smears and adverse pregnancy outcome in low risk population

Objective: Recent studies suggest an association between Human Papilloma Virus (HPV) infection, cervical inflammation and obstetric complications (i.e. spontaneous preterm parturition and cervical insufficiency). It has been proposed that viral inflammation of the placenta causes changes in the mother's immune reaction to bacterial pathogens, which leads to enhanced inflammatory reaction and preterm delivery. Therefore, the aim of this population-based study was to determine the association between abnormal cervical cytology prior to pregnancy and obstetric outcomes. Study design: A Retrospective population-based cohort study was designed, including all women who had a Pap smear up to two years prior to delivery or during first trimester of pregnancy (n = 15,357). Women were divided into the following groups, according to Pap smear results: group 1 – Normal PAP smear (n = 11,261); group 2 – Pap smear with evidence of an inflammatory process (n = 3895); and group 3 – Pap smear with evidence of HPV infection (n = 201). Obstetrical outcomes, gestational age at delivery, and pregnancy complications were compared among the groups. Results: The rate of HPV infection in our study population was 1.3%. The rate of preterm delivery (group 1 – 8.5%, group 2 – 8.5%, group 3 – 7%, p = 0.7), preterm PROM (group 1 – 1.7%, group 2–1.6%, group 3 – 2%, p = 0.66) and cervical insufficiency (group 1 – 0.5%, group 2 – 0.7%, group 3 – 1.5%, p = 0.11) did not differ significantly among the study groups. There was no statistical difference in the rate of premature rapture of membranes, newborn small-for-gestational-age, preeclampsia or placental abruption. Women with abnormal cervical cytology, either due to inflammation or HPV infection, had similar obstetric outcome in comparison to those with a normal cervical cytology. Conclusion: This population-based retrospective cohort study indicates no association between positive HPV testing with Pap smear and obstetric complications such as preterm delivery, cervical insufficiency, placental abruption, PROM, Preterm PROM, neonatal SGA and preeclampsia, in a population with low prevalence HPV infection.