In the last post, I talked about Emily and Brett Robinson and their twin daughters with Twin-Twin Transfusion Syndrome (TTTS). The condition affects about 10-20% of monochorionic twin pregnancies, and it is one of the primary reasons that these pregnancies are followed more closely than dichorionic twins.
When is treatment needed?
We measure monochorionic fetuses for growth every 2-3 weeks. If the measurements are more than 15-20% different from each other, or if there is discordance in the amount of amniotic fluid around each fetus, we begin to suspect TTTS. Some cases are so subtle that they are recognized only after delivery, when one twin is slightly smaller or paler.
Other cases are recognized during the pregnancy, but are so mild that no treatment is needed.
In the case of the Robinson twins, the diagnosis was unmistakable. Rosalie, the larger twin, had a markedly increased amount of amniotic fluid. Violet, the smaller baby, had very little amniotic fluid, and blood flow through her umbilical cord was reduced. Emily and Brett were stunned. They were a young couple, newly married and far from their families. The pregnancy that began as such a blessing had now taken a frightening turn.
Treatment option 1: Amnioreduction
I explained that there are several options for treating TTTS. One of the most common treatments is called amnioreduction. This is an amniocentesis procedure, where a needle is placed into the larger amniotic sac, and excess fluid is removed around the larger fetus. Since babies make amniotic fluid around the clock, this fluid tends to reaccumulate, and we may repeat the procedure as often as once or twice a week. Some studies have shown an improvement in outcomes with this approach. In more severe cases, however, a more effective therapy is preferred – laser ablation.
Treatment option 2: Laser ablation
Laser ablation surgery addresses the cause of TTTS: the blood vessel communications between the fetuses. In this procedure, the surgeon enters the uterus with a tiny scope and, using a laser, interrupts the blood vessels that travel between the babies.
This treatment is not available in all areas of the country, and it is only offered in cases of severe TTTS. The surgery itself carries some risk to mom and babies (infection, ruptured membranes, preterm labor, fetal death), so it is only performed when the risk of fetal death without treatment outweighs the risk of fetal death with this treatment. Results vary, because these babies are sick before the laser surgery is performed, but laser ablation has shown great promise in improving outcomes for both donor and recipient twins.
Treatment for the Robinson twins
In my area, the closest fetal surgery center is located in Houston. After my first visit with Emily and Brett, I contacted Dr. Ken Moise and Dr. Anthony Johnson at The Fetal Center at Memorial Hermann Hospital in Houston.
I described the Robinson twins, and Dr. Moise agreed that they might be candidates for laser ablation treatment. Arrangements were made for Emily and Brett to travel to Houston the following day. Everything was happening quickly now. On Tuesday, they were having a routine ultrasound in my office. Wednesday, they were traveling to Houston and contemplating surgery for their sick babies.
An ultrasound was repeated in Houston when they arrived, and amniocentesis was performed to assure that the babies’ chromosomes were normal (the surgery is not performed if chromosomes are abnormal, because outcomes are not good in that setting). The Robinsons were counseled extensively about the benefits and potential risks of the laser surgery. The couple elected to proceed with the procedure.
The following week, they were back in my office for ultrasound. There was still a difference in amniotic fluid volume between the two fetuses, but Violet’s umbilical cord blood flow had improved, and both babies were active. I saw them weekly for ultrasounds for fetal growth and well-being.
At about 28 weeks, Violet’s growth and blood flow became concerning again.
Emily was hospitalized for close surveillance of her babies, and they were delivered at 32 weeks, when their growth essentially stopped. The babies were admitted to the neonatal intensive care nursery, where Rosalie grew rapidly and went home within four weeks. Violet had a slower start, and was in the NICU for eight long weeks before joining her family at home. Emily practically lived at the hospital for all that time.
I receive holiday pictures of the girls now from year to year; how lively and happy they are! Violet remains smaller than her sister, but they have the same dark hair and the same smile. They look as though they are wondering what all the fuss was about. I should have trusted them from the beginning!
You can read more about Texas Fetal Center here.
Twin-Twin Transfusion Syndrome or TTTS has many treatment options and in many cases isn’t a condition that is even noticed until after birth. Twinning can happen in several ways. When twins share a placenta but have separate amniotic sacs problems can arise. When TTTS is diagnosed, treatment options can be a complex and sometimes even carry high risk.
If you are pregnant with monochorionic with TTTS, take encouragement from Bret, Emily, Violet, and Rosalie. And be sure to talk to your doctor about all of your options and do as much research as possible.