Research article

Human Papillomavirus (HPV) infection in pregnant women and mother-to-child transmission of genital HPV genotypes: a prospective study in Spain

Xavier Castellsagué^1,8 , Teresa Drudis² , Maria Paz Cañadas³ , Anna Goncé⁴ , Ramón Ros⁵ , José M Pérez⁴ , M Jesús Quintana⁶ , Jesús Muñoz¹ , Ginesa Albero^1,7,8 , Silvia de Sanjosé^1,8 and F Xavier Bosch¹

¹Unit of Infections and Cancer (UNIC), Cancer Epidemiology Research Program (CERP), IDIBELL – Institut Català d'Oncologia (ICO), Hospitalet de Llobregat, Barcelona, Spain

²Department of Pathology, European Institute of Oncology, Milan, Italy

³Molecular Biology, General Lab, Barcelona, Spain

⁴Institut Clínic de Ginecologia Obstetricia i Neonatologia (ICGON), Casa Maternitat, Barcelona, Spain

⁵Servei de Ginecologia y Obstetricia, Hospital de Sant Joan de Déu, Martorell, Spain

⁶Department of Epidemiology, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain

⁷Program in Public Health and the Methodology of Biomedical Research, Universitat Autónoma de Barcelona (UAB), Cerdanyola del Vallès, Barcelona, Spain

⁸CIBER en Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain

author email corresponding author email

BMC Infectious Diseases 2009, 9:74doi:10.1186/1471-2334-9-74

Published:	27 May 2009

Abstract

Background

Studies on HPV infection in pregnant women and HPV transmission to the child have yielded inconsistent results.

Methods

To estimate mother-to-child HPV transmission we carried out a prospective cohort study that included 66 HPV-positive and 77 HPV-negative pregnant women and their offspring attending a maternity hospital in Barcelona. To estimate HPV prevalence and genotype distribution in pregnancy we also carried out a related screening survey of cervical HPV-DNA detection among 828 pregnant women. Cervical cells from the mother were collected at pregnancy (mean of 31 weeks) and at the 6-week post-partum visit. Exfoliated cells from the mouth and external genitalia of the infants were collected around birth, at the 6-week post-partum visit, and around 3, 6, 12, and 24 months of age. All samples were tested for HPV using PCR. Associations between potential determinants of HPV infection in pregnant women and of HPV positivity in infants were also explored by logistic regression modelling.

Results

Overall cervical HPV-DNA detection in pregnant women recruited in the HPV screening survey was 6.5% (54/828). Sexual behavior-related variables, previous histories of genital warts or sexually transmitted infections, and presence of cytological abnormalities were statistically significantly and positively associated with HPV DNA detection in pregnant women recruited in the cohort. At 418 infant visits and a mean follow-up time of 14 months, 19.7% of infants born to HPV-positive mothers and 16.9% of those born to HPV-negative mothers tested HPV positive at some point during infants' follow-up. The most frequently detected genotype both in infants and mothers was HPV-16, after excluding untyped HPV infections. We found a strong and statistically significant association between mother's and child's HPV status at the 6-week post-partum visit. Thus, children of mothers' who were HPV-positive at the post-partum visit were about 5 times more likely to test HPV-positive than children of corresponding HPV-negative mothers (p = 0.02).

Conclusion

This study confirms that the risk of vertical transmission of HPV genotypes is relatively low. HPV persistence in infants is a rare event. These data also indicate that vertical transmission may not be the sole source of HPV infections in infants and provides partial evidence for horizontal mother-to-child HPV transmission.