The article aims to present the results of an investigation comparing fetoscopic laser surgery with the aid of darkfield microscope and amniodrainanage in cases of twin-to-twin transfusion syndrome or TTTS. The patients involved in these study-included pregnancies diagnosed after 26 weeks of gestation.

Twin to twin transfusion syndrome happens in pregnancies of identical twins who share a placenta. They are called monochorionic twins. These twins most often share a balanced exchange of blood through communicating blood vessels. In such case, that one twin will act, as the blood donor at one time and the other will be the recipient. In TTTS one twin always donates blood to the other twin. This results to an unbalanced exchange.
In cases of TTTS, the donor twin develops anemia. This will be the result of the ongoing blood loss to the other twin. The donor twin is often smaller. It is because of the increased work required to pump blood for both twins. This leaves this twin less energy to grow. The donor twin also produces less amniotic fluid and may become nearly wrapped in the amniotic membrane because there is so little fluid. The donor twin is often the sicker of the two and the one at higher risk of dying inside the womb.
The recipient twin on the other hand in cases of TTTS is usually larger and overloaded with extra blood. This twin produces too much amniotic fluid because of the excess blood volume. Polyhydramnios is expected and this may cause premature rupture of the membranes and premature labor. The excess fluid may also cause other complications in the recipient twin. This includes cases such as retention of fluid around the lungs or pleural effusion, around the heart or pericardial effusion, in the abdomen or as cites or under the skin.
The study was conducted in Leiden University Medical Centre. It is a tertiary referral hospital for fetal therapy. There were 21 TTTS cases diagnosed and treated after 26 weeks of gestation that was investigated. The treatment options for the TTTS cases in the study consisted of either amniodrainage or fetoscopic laser coagulation of vascular anastomoses. Primary outcomes or adverse outcomes including possible intrauterine or neonatal death, major neonatal morbidity or severe cerebral injury were noted. Secondary outcome involving the gestational age at birth was also observed.

The results of the study were enumerated in the article. Of all the cases, eleven TTTS cases were treated with amniodrainage and then with laser surgery in the study. The results showed that the median gestational age at birth in the amniodrainage group and in the laser surgery group was 29 and 31 weeks respectively. All infants, in both treatment groups, were born alive. The study also showed and compared the morbidity level of the twins in both gestational groups. Major neonatal morbidity occurred more often in the amniodrainage group than in the laser surgery group with 27 percent and 0 percent respectively. It also noted that severe cerebral injury in the amniodrainage group and in the laser surgery group occurred in 23 percent and 15 percent of infants respectively. Neonatal mortality in the amniodrainage group and in the laser surgery group was 14 percent and 0 percent respectively. The overall adverse outcome was 36 percent in the amniodrainage group and 15 percent in the laser surgery group. The authors of the study concluded that in TTTS diagnosed after 26 weeks of gestation, amniodrainage and laser surgery both result in 100 percent survival rate. However, infants born after laser surgery have less major neonatal morbidity. Original article