The mode of childbirth has no affect on whether a child catches hepatitis C from their mother, a new Irish study shows, writes Claire O'Connell
PAMELA ANDERSON has it, along with around 170 million other people around the world. Hepatitis C - a blood-borne infection which in severe cases can lead to liver failure - infects around 3 per cent of the global population. And now a major Irish study has shed new light on how the hepatitis C virus can pass "vertically" from a pregnant mother to her child.
"If a mother has hepatitis C, the chance of the baby getting it is about 4 per cent," says researcher Fionnuala McAuliffe, a consultant obstetrician and gynaecologist at the National Maternity Hospital (NMH) in Dublin and professor of obstetrics and gynaecology at University College Dublin. "We found a rate 0.7 per cent of hep C transmission, so it is a significant enough problem."
Unlike other viruses, such as HIV and hepatitis B, there's no medication to prevent the hepatitis-C virus transferring to the child, and the focus has been on managing the delivery to minimise the risk, explains McAuliffe.
"With HIV in pregnancy, you can give medication to prevent transmission to the baby, and for hepatitis B if you vaccinate the baby at birth that seems to prevent the baby getting [the infection]," she says.
"But for hepatitis C, we don't have any treatment, so people have been looking at the mode of delivery, was there anything we could do there."
The theory goes that during pregnancy the baby is in a protective amniotic sac, but when this ruptures at delivery the baby comes into contact with secretions from the mother and the hepatitis-C virus could be passed on, explains McAuliffe.
But the jury has been out as to whether planning a section gets around the issue, she says. "There's controversy in the literature; some papers have come out saying that a Caesarean section protects, and others say it doesn't."
Now one of the largest studies of its kind has found that the mode of delivery doesn't alter the risk of passing the virus. The review of mothers and babies at the NMH and the Rotunda Hospital in Dublin, published in the American Journal of Obstetrics and Gynaecology, spanned nearly 75,000 births over five years.
Around one third of the pregnant mothers were considered to be at risk of carrying hepatitis C, which can be spread between adults through needle sharing or sexual contact. They were screened during pregnancy for the virus and 545 mothers came up positive.
Analysis of these mothers and their babies found that having a planned Caesarean section, instead of a normal delivery, made no difference to the risk of the baby picking up the blood-borne virus, says Prof McAuliffe.
"In Ireland we haven't tended to do elective C-sections for hepatitis C, and we were looking to see should we change, should we offer a section. But I think the evidence shows that we shouldn't, because it offers no benefit."
Instead, it seems the hepatitis-C virus appears to infect the child while still in the womb, she notes. "That's probably why we didn't find a difference in delivery - the transmission of hepatitis C is happening during pregnancy."
But what does appear to increase the risk of transmission is the presence of the hepatitis-C virus in the mother's bloodstream, and knowing this could help inform doctors when counselling women in pregnancy.
"Some people clear the virus and some people don't," says Prof McAuliffe. "We found that in the women where there was no virus evident in the blood, none of those had babies with hepatitis C. That was an important factor - so you should probably look for the virus [in blood samples] in early and late pregnancy, and if you find none then you can reassure the mother that the chances of the baby getting the virus is really remote."
A pilot study is now assessing whether it is feasible to screen all pregnant women for hepatitis C. "I think we should look towards [routine] antenatal screening," she says.
"It is beneficial for the woman to know because she can use barrier methods with her partner, and hep C is also associated with liver cancer and cirrhosis, so they should be referred to the liver service."