France: In Utero Treatment for Rare Vascular Tumor in Fetus

A baby with a rare vascular tumor (Kasabach-Merritt syndrome) received in utero treatment in France, a pioneering approach for this condition.

The tumor was detected in the seventh month of pregnancy at a maternity clinic in Mulhouse. Doctors administered the drug Sirolimus to the mother, which passed to the fetus through the placenta, inhibiting tumor growth.

On November 14, 2025, Issa was born by Cesarean section. Dr. Alexandra Speeg-Bouvant, a hematologist, stated that the treatment allowed for the stabilization of the dysplasia. Today, Issa is 3 months old and is regularly monitored.

His mother, Vivian, reported that despite the tumor, Issa is a normal child who eats and grows well.