*3.3.2. Management of TAPS*

There is no optimal treatment for TAPS. Options include expectant management and early delivery; intrauterine transfusion (IUT) in the donor, with or without partial exchange transfusion (PET) in the recipient; selective feticide; and fetoscopic laser surgery.

Expectant management is made with closing ultrasound monitoring with serial MCA-PVS evaluation and an early delivery when necessary. It leads to a 75 to 83% survival rate [111, 118].

Another kind of treatment is IUT that can be performed intravascularly or intraperitoneal. It seems the latter may be superior to intravascular intrauterine transfusions because it is technically easier and can be performed as early as 15 weeks [119]. Although this method is commonly used, it is a palliative option, since it temporarily meliorates the donor anemia. Furthermore, the raise in blood viscosity in the recipient twin can lead to embolic complications [67]. These complications can be managed by partial exchange transfusion (PET) that decreases the viscosity of the blood of the polycythemic recipient. The perinatal survival rate in some studies is generally good, reaching 85–100% [111, 118].


\*Critically abnormal Doppler is defined as absent or reversed end-diastolic flow in umbilical artery, pulsatile flow in the umbilical vein, and increased pulsatility index or reversed flow in ductus venosus.

**Table 3.** Antenatal TAPS classification. Adapted from Ultrasound Obstet Gynecol. Slaghekke et al. [111].

The only causal treatment for both spontaneous and post-laser TAPS is laser surgery. It is technically more difficult because of the absence of polyhydramnios and a stuck twin, which makes the visualization of the vascular equator more challenging as well as the size of anastomoses, which is difficult to visualize during fetoscopy [111]. The results in small studies are satisfactory, with a survival rate of 94–100% [111, 118, 120, 121] and an apparent improvement in perinatal outcome by prolonging pregnancy and reducing respiratory distress syndrome [117].

The TAPS management should be made after evaluation of different factors, including TAPS stage, gestational age, and the clinician experience in the different types of treatments. In early stages, TAPS can be managed expectantly. If gestational age is below 26–28 weeks, laser treatment should be considered [113]. When laser treatment is not possible, IUT should be considered. When repeated IUT is expected or in case of severe polycythemia in the recipient, PET of the recipient can be done.
