France: First successful treatment for a fetus with a rare intrauterine tumor

In an unprecedented medical achievement described by experts as a "world first," a French medical team successfully saved the life of a fetus suffering from a rare and life-threatening vascular tumor while still in its mother's womb. This complex procedure, performed at a hospital in Mulhouse, eastern France, opens new horizons in the field of fetal medicine and the treatment of rare diseases before birth.

Accurate diagnosis at a critical stage

The story began in the late seventh month of pregnancy when doctors discovered that the fetus had Kasabach-Merritt syndrome. This syndrome is a rare disorder characterized by a rapidly growing hemangioma, which consumes platelets and clotting factors, posing a serious threat to the fetus's life.

According to Dr. Chris Minella, speaking at a press conference held at the Mother and Child Hospital in Mulhouse, tests revealed a tumorous mass at the level of the fetus's neck. The tumor was growing so rapidly that it had begun to extend into the fetus's face, threatening to obstruct the airway and cause immediate suffocation—a highly complex medical situation requiring urgent and unconventional intervention.

A therapeutic innovation as an alternative to surgery

Faced with this medical challenge, and instead of resorting to traditional surgical interventions that could carry high risks to both mother and fetus, coordination was established with a specialized center for rare diseases in Lyon. Professor Laurent Guibault, who was overseeing the case, proposed an innovative treatment protocol based on medication.

The treatment involved administering sirolimus to the mother. Sirolimus is an immunosuppressant drug typically used to prevent organ transplant rejection, but it has also proven effective in treating certain vascular malformations. The ingenious aspect of this approach was the drug's ability to cross the placental barrier and reach the fetus via the mother's bloodstream. This allowed for the suppression of the hemangioma's growth and the reduction of the new blood vessels that supplied it, all without the need for any direct surgical intervention in the uterus.

Successful delivery and stable condition

Thanks to this delicate medical intervention, the efforts were successful, and baby Issa was born on November 14, 2025, via cesarean section. His mother, Vivian (34 years old), confirmed that her son, now three months old, is doing well, saying, "Despite the tumor, he eats and grows well." The infant is currently under regular medical supervision and continues to receive treatment with sirolimus to ensure complete control of the condition.

The importance of achievement and its future impact

This success represents a turning point in fetal medicine for several reasons:

• Avoid complex surgeries: This achievement proves that fetal tumors can be treated medically via the mother, reducing the need for open fetal surgeries or endoscopies that carry the risks of miscarriage or premature birth.
• Hope for rare diseases: This treatment gives new hope to families facing prenatal diagnoses of diseases that were previously considered fatal or untreatable.
• Medical collaboration: The event highlights the importance of collaboration between public hospitals and research centers specializing in rare diseases to reach innovative solutions.

This event is further evidence of the rapid development of healthcare in France and the ability of medical staff to handle the most complex cases, setting new standards for fetal care worldwide.