Monochorionic twins with selective intrauterine growth restriction and intermittent absent or reversed end-diastolic flow (Type III): feasibility and perinatal outcome of fetoscopic placental laser coagulation.

OBJECTIVES

To assess the feasibility and impact on perinatal outcome of fetoscopic laser coagulation of placental anastomoses in monochorionic twins with selective intrauterine growth restriction (sIUGR) and intermittent absent or reversed end-diastolic flow (iAREDF) in the umbilical artery (Type III), in comparison with expectant management.

METHODS

This is a descriptive study of the outcome of 18 cases of monochorionic twins with Type III sIUGR treated with laser, and 31 pregnancies managed expectantly over the same period. All newborns underwent neonatal brain ultrasound scans. Perinatal outcome and the incidence of neurological damage were compared between the two groups.

RESULTS

Laser coagulation could be performed in only 88.9% (16/18) of cases owing to technical difficulties, and in 12.5% (2/16) a second procedure was required to achieve complete coagulation of the large artery-to-artery anastomosis. Mean gestational age at delivery was 31.0 (range, 26-33) weeks in the expectant management group and 32.6 (range, 23-38) weeks in the laser group (P = 0.32). Overall perinatal survival was 85.5% (53/62) and 63.9% (23/36), respectively (P = 0.02). Intrauterine demise of the smaller twin occurred in 19.4% (6/31) and 66.7% (12/18), respectively (P = 0.001), and was associated with death of the cotwin in 50% (3/6) and 0% (0/12) of these cases, respectively (P = 0.02). The prevalence of periventricular leukomalacia in the larger fetus was 4/28 (14.3%) in the expectant management group and 1/17 (5.9%) in the laser group (P = 0.63).

CONCLUSIONS

Laser coagulation in sIUGR-iAREDF pregnancies is technically difficult and not always feasible. Placental dichorionization significantly increases the proportion of fetuses with intrauterine death of the growth-restricted twin, but it protects the normal twin from its cotwin's death in the event of demise of the growth-restricted twin.