Amniotic septostomy for the treatment of the stuck twin sequence

OBJECTIVE: To report our experience of intentional puncture of the intervening membrane ("septostomy") and subsequent pregnancy outcome for twin gestations complicated by the stuck twin sequence. STUDY DESIGN: Nine patients were diagnosed with a stuck twin sequence based on polyhydramnios in the larger twin and severe oligohydramnios and discordant growth in the smaller twin. A 22 gauge spinal needle was used to perform a diagnostic and limited reduction amniocentesis of the polyhydramniotic sac followed by selective puncture of the membrane between the twins. Immediate and long-term observations were made regarding subsequent fetal growth and pregnancy outcomes. RESULTS: Amniotic septostomy was performed in 5 second trimester and 4 third trimester pregnancies (median gestation: 21.6 weeks, range: 16.9-27.0 weeks). The median discordance based on ultrasound estimates of fetal weight was 34% (10-12%). Immediate decompression of the "stuck twin" occurred in all cases followed by increased fetal movement, and improved umbilical artery velocimetry. Three of the 18 fetuses (17%) died in utero in two of the affected pregnancies. Delivery occurred at a median of 34 weeks' gestation (21.6-3.5.0). The median discordance at delivery as 31.5% (19-44%) suggesting no worsening of growth discrepancy after the septostomy was performed. No incidences of cord entanglement were encountered. CONCLUSIONS: Anmiotic septostomy may be utilized to treat the stuck twin sequence with a perinatal survival of up to 83%.