A retrospective study from September 2017 compares laser surgery for Twin to Twin Transfusion Syndrome (TTTS) performed before and after 17 weeks of gestation. The results were published in Ultrasound in Obstetrics & Gynecology. That is the official journal of the International Society of Ultrasound in Obstetrics & Gynecology (ISUOG). The twins included in the study were all diagnosed with severe stages of TTTS. 53 women pregnant with monochorionic diamniotic (mo-di) twins were included in the study. They all had laser surgery before 17 weeks. They were compared to a control group of 91 women who had laser surgery between 17 and 26 weeks.
Higher risk of delivering preterm
The median gestational age* of the babies who were treated before 17 weeks of gestation was 16+1 weeks – ranging from 15+0 weeks to 16 +6 weeks. The study found that the women who had laser surgery before 17 weeks of gestation were more likely to have a shorter intervention time – 17 minutes. That’s compared to 24 minutes for the control group with women who underwent surgery later in the pregnancy. The women who had laser surgery early on also had a higher risk of delivering extremely preterm before 28 weeks.
The median gestational age is the value for which 50 percent of the babies are above, and 50 percent are below.
Laser surgery is best option
The researchers concluded that it is possible to perform laser surgery before 17 weeks of gestation. However, it seems to be associated with an increased risk of extreme preterm birth compared to surgery later in the pregnancy. Regardless, they did stress that in early severe cases of TTTS, laser surgery may be the best option. They recommend, that parents should be counselled that – in the majority of cases – the outcome after birth is favorable.