Malaria kills hundreds of thousands of people every year, especially young children. It’s also exceptionally dangerous to another at-risk group: pregnant women.

Researchers have estimated that 10 to 20 percent of maternal mortality in countries where malaria is endemic is malaria-related. That’s almost 30,000 women every year. Pregnancy loss, and long-term disability caused by exposure to malaria in utero, are even more common. And many drugs that are used to save people dying of malaria are not safe to use during pregnancy, or are not widely used even though they are safe.

A new study published in The Lancet: Child and Adolescent Health offers a comprehensive account of just how much this deadly disease affects pregnant women — and suggests that changing treatment options could significantly improve the situation.

Malaria is caused by parasites that are transmitted to people from mosquito bites. Last year, there were more than 200 million cases of malaria, and at least 400,000 deaths, mostly among young children. It is still one of the world’s deadliest killers.

The good news is that public health efforts have made a big difference in reducing malaria deaths: Insecticide-treated bed nets and seasonal preventative malaria treatment both have a strong, well-supported track record, and have saved hundreds of thousands of lives. Addressing malaria is one of the world’s most cost-effective giving opportunities, and one we’ve often recommended here at Vox.

But the official numbers may underestimate malaria’s toll, because they mostly do not include stillbirths, neonatal deaths from low birth weight, and late-term pregnancy loss.

And while most people who live in malaria-endemic areas have acquired immunity to malaria by the time they are adults, this immunity doesn’t fully transfer to the fetus. The result is that when women contract malaria while pregnant, they face a significantly elevated risk of miscarriage.

Read the full article about malaria treatment for pregnant women by Kelsey Piper at Vox.