In Utero Laser Surgery Saves Twins

Eighteen weeks pregnant with twin girls, Shelby Scanlon sensed something might be wrong when her ultrasound technician left the room during a routine scan. When the technician returned, this time with multiple doctors, Scanlon, 27, took a deep breath.  

The doctors suspected a rare condition called twin-to-twin-transfusion syndrome (TTTS). It’s a problem that occurs only in identical twins who share a placenta. It means the blood flow through the shared placenta is unequal between the two fetuses. If left untreated, advanced stages of TTTS are fatal for one or both of the unborn babies in more than 80 percent of cases.

Scanlon was instructed to go to the Yale Medicine Fetal Care Center immediately. With no time to process what was happening, the stay-at-home mother left the University of Connecticut Health Center office in Farmington and drove herself to New Haven.

“I knew a little about twin-to-twin-transfusion syndrome from researching the risks of having twins. But I never thought I’d be part of the 10 percent of identical twin cases that it affects,” says Scanlon, who lives in Waterbury with her fiancé and children (ages 5, 3, and 2). “There are terrifying thoughts that race through your mind at a time like that. It was all very overwhelming.”

When she arrived at the Fetal Care Center that Friday afternoon, she had another ultrasound, which confirmed the diagnosis. Scanlon was referred to Mert Ozan Bahtiyar, MD, medical director of the Fetal Care Center, and a leader in treating twin-to-twin-transfusion syndrome.

He explained her condition in depth.

In about 80 to 90 percent of identical twins (in which they share a placenta), blood distribution between the two babies is fairly equal. “But if there are abnormal blood vessel connections in the placenta, the blood transfusion is imbalanced,” Dr. Bahtiyar says. “One twin gets more blood than the other, which can lead to twin-to-twin-transfusion syndrome.”

When this happens, one twin, who is called the “donor twin,” pumps blood to the “recipient twin.” The extra blood causes the recipient’s kidneys to produce more urine, which creates a large bladder. This, in turn, can lead to too much amniotic fluid (polyhydramnios), prenatal heart failure, or excessive swelling (hydrops).  

The syndrome, which has no known genetic cause, occurs in 10 to 15 percent of identical twin pregnancies in which there is a shared placenta. It typically develops between weeks 16 and 26 of a woman’s pregnancy, and action should be taken immediately to stop the progression in advanced stages.

In Scanlon’s case, because the donor twin’s bladder could not be seen as “filled” with urine during the ultrasound examination, her TTTS was considered advanced, Dr. Bahtiyar explains. Fortunately, there were no heart problems.

“I was told that usually, at this point, issues with the heart can start, but luckily, there were no signs of swelling or anything like that,” says Scanlon, who had no complications in her other three pregnancies. “But I was right on the border of something very bad happening, which made it nerve-racking.” 

Scanlon really had only one option.

“The published research shows us that for advanced-stage TTTS, if no intervention is made, in more than 80 percent of cases, there is a fetal fatality, for one or both of the twins,” Dr. Bahtiyar says.

Based on a large study published in Europe in 2004, laser fetoscopy, an in utero procedure, is shown to be the best treatment for advanced stages of TTTS.

Luckily, Dr. Bahtiyar was familiar with the procedure. He performed the first-ever laser fetoscopy (called selective laser photocoagulation) in Connecticut at Yale New Haven Hospital in 2005. Since that time, the Fetal Care Center has become a referral center for the specialized surgery, treating patients throughout Connecticut, New England, and beyond. The Fetal Care Center is one of only about three dozen centers that offers the procedure in the U.S.

With laser fetoscopy, Dr. Bahtiyar makes a small incision in the mother’s abdomen and inserts a tiny instrument equipped with a laser, which burns the unequal blood vessel connections to correct the imbalanced blood flow. He then drains the excessive amniotic fluid around the recipient twin. The biggest risk, Dr. Bahtiyar explains, is rupturing the amniotic sac, which could lead to premature labor.

After speaking with Dr. Bahtiyar, Scanlon decided to move forward with the surgery, which was scheduled for two days later at Yale New Haven Hospital. “I really had no choice,” she says. “I kept saying to myself, ‘This is really happening.’ It was weird, since the pregnancy had been going so perfectly.”

Still, she says she felt confident with her decision and was eager to get the surgery over with. The morning of the laser fetoscopy, she was given local anesthesia and partial sedation. The procedure took about 15 minutes and was a success. She spent one night in the hospital.

“I didn’t feel any pain during or after surgery, and later had only a few minor contractions,” she says. “The next morning, an ultrasound showed that one baby had already regained her bladder back. The other twin was fine. The doctors did another ultrasound before I was discharged, and then a follow-up one a week later and everything looked good. They saw me once more, and then I went back to my normal routine with ultrasounds at UConn.”

Unsurprisingly though, Scanlon says she was nervous throughout the rest of her pregnancy. “The waiting was hard, and I was going to see my Ob/Gyn two times a week from 32 weeks on, just so they could keep checking me,” she says. “But thankfully, everything was always perfectly fine.”

In November 2017, Scanlon delivered the twins (Sarah and Savannah) at 36 weeks. Both girls are now home and doing well. On an early spring day in their home, the busy parents—and a set of grandparents—juggled keeping the three older kids busy while Mike Spielman, Scanlon’s fiancé, bounced Savannah, and Scanlon cradled a dozing Sarah.

“They are both happy babies and even though this was a lot to take in, we are all doing great,” Scanlon says. “Words cannot describe how grateful we are that the surgery worked.”

To learn more about the Yale Medicine Fetal Care Center, click here.