Human papillomavirus infections during pregnancy and adverse pregnancy outcomes: a Scandinavian prospective mother-child cohort study.

Background: Human papillomaviruses are common in the urogenital tract amongst women of childbearing age. A few studies indicate a possible association between human papillomavirus infections in pregnancy and adverse pregnancy outcomes whilst other studies find no such association. We aimed to investigate the association between human papillomavirus infections during pregnancy and adverse pregnancy outcomes linked to placental dysfunction, including hypertensive disorders of pregnancy, gestational diabetes mellitus and newborns small for gestational age.

Materials and methods: Pregnant women from the general population in Norway and Sweden were enrolled at the time of routine mid-gestational ultrasound examination. Urine samples collected at mid-gestation in 950 and at delivery in 753 participants, were analyzed for 28 human papillomavirus genotypes, including 12 high-risk genotypes. Participants completed electronic questionnaires at enrollment and medical records were reviewed for background characteristics and for the following adverse pregnancy outcomes: hypertensive disorders of pregnancy including gestational hypertension, preeclampsia, superimposed preeclampsia, eclampsia and Hemolysis Elevated Liver enzymes and Low Platelets (HELLP) syndrome, gestational diabetes mellitus, and newborns small for gestational age. Associations between adverse pregnancy outcomes and (a) any human papillomavirus, high-risk human papillomavirus and human papillomavirus genotype 16 infection at mid-gestation, (b) multiple genotype infections at mid-gestation, and (c) persisting infections during pregnancy were assessed with univariable and multivariable logistic regression models. Missing covariates were imputed using multiple imputation.

Results: At mid-gestation, 40% (377/950) of women were positive for any of the 28 genotypes, 24% (231/950) for high-risk genotypes and human papillomavirus 16 was found in 6% (59/950) of the women. Hypertensive disorders of pregnancy was observed in 9% (83/950), gestational diabetes mellitus in 4% (40/950) and newborns small for gestational age in 7% (67/950). Human papillomavirus infection with any genotype, high-risk or human papillomavirus genotype 16 at mid-gestation was not associated with adverse pregnancy outcomes. No associations were found for multiple genotype infections at mid-gestation or persisting infections.

Conclusion: In a general population of pregnant women, we found no evidence of human papillomavirus infections during pregnancy being associated with hypertensive disorders of pregnancy, gestational diabetes mellitus, or newborns small for gestational age.

Trial registration: Trial registration The study is registered at ClincialTrials.gov; NCT02449850 on May 19th, 2015.