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PrEP during pregnancy: safety findings provides further reassurance

Hester Phillips

22 February 2023

South African study finds no link between PrEP use during pregnancy and preterm births or small infant size at birth

A pregnant woman cradling her bump with another woman
Photos are used for illustrative purposes. They do not imply health status or behaviour. Credit: iStock/liderina

Evidence on whether PrEP is safe for pregnant women to take has been slow to emerge. But findings from South Africa provide further reassurance.

What is the research about?

Whether it is safe for pregnant women to take PrEP.

The trial took place in Durban, South Africa. It involved 540 women who were all between 14–28 weeks pregnant when the study started. Half of the women started taking daily PrEP pills straight away, the other half took PrEP after they had given birth and stopped breastfeeding.

Why is this research important?

In sub-Saharan Africa, pregnant and breastfeeding women are at increased risk of HIV due to biological changes that happen during pregnancy and having condomless sex. If a woman gets HIV when she is pregnant or breastfeeding she can pass HIV on to her baby unless she is diagnosed as HIV-positive and both her and her baby get treatment.

Since 2017, the World Health Organization has recommended PrEP for pregnant women at high risk of HIV. This is based on various evidence. But there is still limited data on PrEP use in pregnancy, and many countries have been slow to adopt this as policy. In South Africa, for example, pregnant and breastfeeding women could not get PrEP until December 2019. This study took place between 2017 and 2019, before the policy change happened.

What did they find out?

Taking PrEP did not increase incidents of preterm birth (birth at less than 37 weeks) or small birth sizes.

The trial stopped early due to the PrEP policy change. This resulted in a lack of data on other events, such as births at less than 34 weeks, stillbirths and low birthweights. But overall, 15% of participants had at least one bad pregnancy outcome (defined as any of the following: preterm birth, low birthweight, stillbirth or small birth size). There was no difference between groups on this measure.

More women who took PrEP during pregnancy had pre-eclampsia or haemorrhage than women in the other group. But these are common conditions for pregnant women in sub-Saharan Africa so this was not a significant finding.

PrEP adherence among women who started PrEP during pregnancy was between 87% and 95%. Around 17% of participants missed doses during the first 2–4 of taking PrEP. Having nausea and vomiting, headaches or forgetting to take their pills were the main reasons for this. Women who took PrEP while pregnant were more likely to get nausea and vomiting than women in the other group. But this side-effect went away after a month of taking PrEP.

There were two miscarriages and 17 stillbirths across the two groups. The proportion of foetal deaths (4%) among the group of women taking PrEP during pregnancy was similar to the rate among the general population of women (3·6%).

There was no difference in kidney function between the two groups.

What does this mean for HIV services?

The most pressing issue is to raise people’s awareness that PrEP is safe for pregnant women to take. This includes men as well as women, as men are likely to influence their partner’s decisions.

One of the biggest challenges will be to support women to accurately self-assess their HIV risk. This may be particularly difficult if their partner is unwilling to test for HIV or if the woman is doing something that is criminalised or stigmatised, such as selling sex, taking drugs or having transactional sex.

Another big issue is whether PrEP is available, and this really depends on location. Even in places where pregnant women can get PrEP, people may link it to promiscuity which can stop women from taking it. Working with peers who can speak to other women about taking PrEP, and setting up women-only PrEP support groups, can help to address misconceptions and stigma. Support groups are also a good way to deal with the sickness pregnant women may experience when they first take PrEP.

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