Nicole Shore had enough to worry about when she and her husband Ari found out they were having twins. New car, maybe even a new house; the logistical challenges of going suddenly from one kid to three. She worried about what would happen after she delivered, not before.

“We just thought we were having a natural pregnancy,” she says.

But when the contractions came on hard at 22 weeks, she worried. She went to her doctor, who ordered an ultrasound. “I went to get the results and they said, you need to make an appointment with Timothy Crombleholme [M.D.] immediately. Like, don’t mess around,” she says.

Within the two weeks since her previous ultrasound, Nicole’s twins had developed twin-to-twin transfusion syndrome (TTTS). Mila, the larger of the two, was getting an overwhelming share of amniotic fluid and placental blood, causing her system to work overtime to process it; the smaller, Ciela, lacking fluid and blood, had withered. “Ciela was wrapped in the amniotic sac like cellophane,” says Nicole.

The problem is vascular connections in the placenta that allow the twin fetuses to share blood. It’s these connections that let the imbalance develop. “The mortality rate for this condition is extraordinarily high without treatment, approaching 100 percent for both twins,” says Dr. Crombleholme, director of the Colorado Fetal Care Center at Children’s Hospital Colorado.

The most effective treatment method, Dr. Crombleholme told Nicole, was also potentially the riskiest: fetoscopic laser ablation, in which the surgical team uses a laser to eliminate the vascular connections between twins.

Dr. Crombleholme and his team begin by mapping out, one by one, the hundreds of vessels on the placenta, marking each spot they intersect — typically between three and 60 connections. Then Dr. Crombleholme inserts a fetoscope into the amniotic cavity through a three-millimeter incision, zaps each connection with a laser, and seals it off.

The process is astonishingly meticulous. If Dr. Crombleholme’s laser overlooks even a single vessel, the TTTS persists. The operation fails. Success demands both precision and speed. When Dr. Crombleholme started doing the operation 20 years ago, it took about 10 to 20 minutes to complete. Not long, but survival has everything to do with timing. A procedure of under five minutes results in a 92 percent survival rate for the donor twin — the smaller of the two, and the one less likely to survive. At 10 minutes that rate falls to 78 percent. Today, Dr. Crombleholme averages two and a half minutes. The CFCC’s survival rates are 97 percent survival of one or both twins and 85 percent survival of both twins (without intrauterine growth restriction).

“Our survival rates are the best in the world,” he says.

Whether to do the surgery or not wasn’t hard for Nicole and Ari to decide.

“My husband and I didn’t even talk about it,” Nicole says. “We just looked at each other and knew we had to get it done.”

It worked. Mila and Ciela were born at 32 weeks gestation. Weighing less than three pounds, both spent about a month in the Neonatal Intensive Care Unit at Children’s Colorado for stabilization and management.

Now two years old, they’re thriving — nothing about them suggests the life-threatening trauma they went though before they were born. “Healthy, happy,” Nicole says. “They”re great.”

Jef Otte

Jef Otte is a copywriter at Children’s Hospital Colorado.