New study links HPV to pregnancy complications

HPV is considered the most common sexually-transmitted infection in the world. Photo / iStock

A landmark New Zealand study has linked human papilloma virus with several pregnancy complications including the potentially fatal disorder pre-eclampsia.

University of Otago researchers found that human papilloma virus (HPV) can infect placentas and could be linked to pregnancy complications.

Researchers used techniques to show that HPV had infected three-quarters of the placentas studied.

A placenta infected with HPV led to delivery about one week earlier than expected, and in a quarter of positive cases, this meant a premature delivery.

Ten per cent of infected placentas also developed another infection of the membranes called acute chorioamnionitis.

Dr Noelyn Hung said the research showed not every placenta infected with HPV would have problems.

The study was not geared to prove that an HPV infection in a placenta caused pregnancy complications, Dr Hung said, but the links between the two suggested an HPV infection in a placenta could contribute to complications.

"While further investigation is required into this link, our study provides additional evidence to support HPV vaccination.

"If pre-eclampsia, which is estimated to affect around 5 per cent of deliveries, is indeed caused or compounded by HPV then vaccination becomes an important pregnancy protection measure."

The research showed that 78 per cent of the HPV-infected placentas showed "high risk" types of the cancer-causing virus.

All of the 20 women in the study who had pre-eclampsia, a dangerous disorder that involves maternal high blood pressure and organ damage, were found to be infected with high-risk HPV.

One pattern of infection, which was in 15 per cent of infected placentas, was also associated with lowered foetal birth weight (foetal growth restriction), in addition to prematurity and acute chorioamnionitis.

The research, newly published in the US journal Modern Pathology, was based on a study of 339 of 720 placentas collected through the 2009-2014 Otago Placenta Study.

What is HPV?

• HPV is considered the most common sexually-transmitted infection in the world.

•There are no symptoms for an HPV infection.

•HPV comes in over 100 different forms.

•Some HPV types infect the genital area and may cause warts.

•Other types of HPV can cause abnormal cell changes in the cervix and high-risk types cause cancer.

•Girls and young women aged 9 to 20 can receive Gardasil vaccine free under the Ministry of Health's HPV Immunisation Programme.

Source: The New Zealand HPV Project