Hepatitis C increases the risk of premature delivery for pregnant women with HIV

Hepatitis C increases the risk of premature delivery for pregnant women with HIV

Karolina Nowicka at HIV Glasgow 2018. Image credit: HIV Glasgow

Co-infection with hepatitis C greatly increases the risk of pre-term delivery for pregnant women with HIV, Polish researchers reported this week at the International Congress on Drug Therapy in HIV Infection (HIV Glasgow 2018). Women with hepatitis C and HIV co-infection were at least four times more likely to have a premature birth compared to women with HIV alone, Karolina Nowicka of the Medical University of Warsaw reported.

Premature delivery is a major risk factor for poor infant health and survival, especially in infants born prior to 28 weeks.

Chronic hepatitis C infection is a risk factor for pre-term delivery and some studies have found that antiretroviral treatment increases the risk of pre-term delivery.

Glossary

boosting agent

Booster drugs are used to ‘boost’ the effects of protease inhibitors and some other antiretrovirals. Adding a small dose of a booster drug to an antiretroviral makes the liver break down the primary drug more slowly, which means that it stays in the body for longer times or at higher levels. Without the boosting agent, the prescribed dose of the primary drug would be ineffective.

nucleoside

A precursor to a building block of DNA or RNA. Nucleosides must be chemically changed into nucleotides before they can be used to make DNA or RNA. 

prospective study

A type of longitudinal study in which people join the study and information is then collected on them for several weeks, months or years. 

sample

Studies aim to give information that will be applicable to a large group of people (e.g. adults with diagnosed HIV in the UK). Because it is impractical to conduct a study with such a large group, only a sub-group (a sample) takes part in a study. This isn’t a problem as long as the characteristics of the sample are similar to those of the wider group (e.g. in terms of age, gender, CD4 count and years since diagnosis).

sample size

A study has adequate statistical power if it can reliably detect a clinically important difference (i.e. between two treatments) if a difference actually exists. If a study is under-powered, there are not enough people taking part and the study may not tell us whether one treatment is better than the other.

Polish researchers looked at the outcomes of all pregnancies in women receiving care at the HIV Out-Patient Clinic at Warsaw Hospital for Infectious Diseases between 2006 and 2017 to identify the prevalence and risk factors for pre-term birth (before 37 weeks).

One hundred and fifty-nine pregnancies were identified, of which 19 resulted in pre-term delivery (11.9%). Mothers had a median age of 31 years and 27% had chronic infection with hepatitis C at the time of pregnancy. Thirty-one per cent reported drug use during pregnancy and 13% were receiving methadone as opioid substitution therapy.

Fifty-two per cent were taking antiretroviral treatment prior to conception, the remainder started antiretroviral treatment during pregnancy and just over 20% had a detectable viral load at the time of delivery. The predominant form of treatment was a boosted protease inhibitor (89.9%) and the most common nucleoside combinations used during pregnancy were tenofovir plus lamivudine or emtricitabine (44.6%) or zidovudine and lamivudine (44%). Five per cent received abacavir and lamivudine. Three women received dolutegravir during pregnancy.

The median gestation period at the time of delivery in women who delivered prematurely was 36 weeks (interquartile range 34-36), compared to 38 weeks in the normal delivery group (p < 0.001).

Although the risks associated with pre-term delivery are much greater if a baby is born prior to 32 weeks, and especially if born prior to 28 weeks, infants born between 32 and 37 weeks of pregnancy may suffer complications such as low blood pressure, breathing difficulties, low blood sugar and weakness in feeding. Babies born at this stage may need specialised care to help them feed.

In a univariate analysis, pre-term birth was associated with an NRTI backbone of abacavir/lamivudine, use of dolutegravir, hepatitis C infection or drug use during pregnancy.

But after adjustment for demographic factors, the only variable that was a significant predictor of pre-term birth was chronic hepatitis C infection (adjusted odds ratio 4.31, 95% confidence interval 1.32 -14.1, p = 0.016).

The investigators said that the small sample size means that any association between dolutegravir and pre-term birth needs to be treated with caution and investigated in larger datasets with prospective follow-up.

References

Nowicka K et al. HCV co-infection is a strong risk factor for pre-term birth among HIV-positive women on cART – data from the HIV Out-Patient Clinic in Warsaw. International Congress on Drug Therapy in HIV Infection (HIV Glasgow), Glasgow, 2018, abstract P005.

View the abstract in the Journal of the International AIDS Society abstract supplement.