Infantile hemangiomas may grow rapidly much earlier than previously thought, new research shows.

According to the new study, the most rapid hemangioma growth of superficial hemangiomas occurs between 5.5 and 7.5 weeks of age. Previously, physicians believed that the tumors grew during the first 5 months of life.

The study, which appears online in the journal Pediatrics, suggests that babies with complication-causing hemangiomas should be immediately referred to dermatologists for further evaluation, preferably by 4 weeks old. Potential complications include permanent disfigurement of the face or functional compromise of vital organs.

“Our goal was to try to figure out when this actual period of rapid growth happened,” says Megha Tollefson, MD, a Mayo Clinic Children’s Center researcher and pediatric dermatologist in a press release. “Then we could potentially intervene if we had to.” Drug treatment and laser therapy are potential treatments.“Depending on where the hemangioma is located, it could potentially have long-term impact,” Tollefson says. “We now have the possibility of preventing a lot of that.”