MRI diagnosis of preterm prelabor rupture of membranes and uterine puncture site-amniotic cavity fistula following fetoscopic laser photocoagulation.

Preterm prelabor rupture of membranes (PPROM) following fetoscopic laser photocoagulation (FLP) is a rare but potentially life-threatening complication. The occurrence of PPROM with a uterine puncture site–amniotic cavity fistula and localized fluid collection in the vesicouterine pouch has not been previously reported, and its diagnosis and management present significant clinical challenges. A 27-year-old primiparous woman with monochorionic diamniotic (MCDA) twin pregnancy was diagnosed at 17 weeks of gestation with Quintero stage I twin–twin transfusion syndrome (TTTS) complicated by type I selective fetal growth restriction (sFGR), an adherent donor twin, and velamentous cord insertion. Following multidisciplinary consultation and comprehensive counseling, she underwent FLP using the SOLOMON technique at 17 weeks and 1 day of gestation. Routine postoperative ultrasound surveillance at 19 weeks and 6 days revealed a slit-like defect in the anterior uterine wall with an adjacent fluid collection, initially raising suspicion of amniotic sac prolapse. Fetal MRI at 20 weeks confirmed PPROM with uterine puncture site–amniotic cavity fistula, localized amniotic fluid accumulation in the vesicouterine pouch, and intracranial abnormalities in both fetuses—including right lateral ventriculomegaly and, in the recipient twin, focal parenchymal atrophy and abnormal signal intensity in the right cerebral hemisphere. Serial ultrasound examinations demonstrated progressive enlargement of the uterine wall defect, increasing fluid accumulation in the vesicouterine pouch, and worsening oligohydramnios. After repeated multidisciplinary discussions and thorough counseling, the patient elected termination of pregnancy. Post-induction laparoscopic exploration confirmed a healed puncture scar on the anterior uterine wall with no overlying amniotic membrane. This case highlights a rare but serious fistulous complication after FLP for stage I TTTS with sFGR. It underscores the importance of systematic postoperative imaging surveillance and the critical role of MRI in definitive diagnosis. The report also prompts reflection on the timing of intervention in borderline-indication cases and the need for individualized counseling that includes expectant management as a potential alternative.