Overview

In the world’s first attempt, a group of research doctors in the United States and Canada successfully treated a baby while she was still a fetus for a rare and often fatal genetic disease that caused the deaths of two of her sisters. The toddler is now 16 months old and doing well, though she still requires follow-up treatments.

The science and other stuff to know

Doctors have been treating fetuses for years, often through surgeries and blood transfusions. However, they hadn’t managed to treat genetic disease conditions with medicine, until now.

In a case study published in the New England Journal of Medicine, a team of doctors treated a fetus with the deadly Pompe disease while it was still in the womb. This disease is a rare genetic disorder characterized by abnormal buildup in cells of a complex sugar molecule called glycogen, impairing the workings of different organs and tissues.

To introduce the medicines to the fetus, researchers delivered crucial enzymes through a needle inserted through the mother’s abdomen and guided into a vein in the umbilical cord. The baby, named Ayla Bashir, received six biweekly drug infusions that started at about 24 weeks of gestation. Thankfully, the treatment worked.

“The innovation here wasn’t the drug and it wasn’t accessing the fetal circulation,” Pranesh Chakraborty, a metabolic geneticist at Children’s Hospital of Eastern Ontario, told AP News. “The innovation was treating earlier and treating while still in utero.”

So what?

The baby is now one and a half years old and she’s an active, happy toddler who has met her developmental milestones, according to her parents. She previously lost two of her older sisters to Pompe disease but the in-utero treatment gave her a chance at life. The hope is that Ayla’s early treatment will reduce the severity of the disorder.

“It holds a glimmer of hope for being able to treat [diseases] in utero instead of waiting until the damage is already well-established,” said Karen Fung-Kee-Fung, a maternal-fetal medicine specialist at The Ottawa Hospital who gave the treatment and delivered Ayla.

The baby currently receives ongoing enzyme infusion treatments to suppress her immune system. She’ll likely receive the infusions for the rest of her life unless a new treatment emerges.

What’s next?

It’s too early to know whether this fetus therapy will become an accepted treatment for Pompe disease. But the future looks promising, according to Christina Lam, interim medical director of biochemical genetics at the University of Washington and Seattle Children’s Hospital in Seattle.

“It’s going to take some time to establish the evidence to definitively show that the outcomes are better,” she said.