Design: This is an IRB-exempt case report. Systematic literature review found no other reports describing post frozen embryo transfer (FET) RPOC in an isthmocele with postoperative fertility follow up.

Setting: Academic tertiary referral center. Patient positioned in dorsal lithotomy with Trendelenburg.

Patients or Participants: A 31-year-old G1P1001 with a history of peritoneal factor infertility and prior low transverse cesarean section. Second pregnancy was achieved via FET. At 6 weeks, ultrasound confirmed missed abortion, which was treated with misoprostol, resulting in downtrending bHCG but persistent vaginal bleeding. Ultrasound showed RPOC in the anterior uterine segment and MRI confirmed a 5.4 x 6.0 x 5.8 cm heterogeneous mass within the cesarean scar defect.

Interventions: After failed methotrexate treatment, with consideration for preserving fertility, the patient opted for minimally invasive evacuation of RPOC and isthmoplasty. Surgical resection began hysteroscopically with laparoscopic guidance, where RPOC were removed using the MyoSure. Robotically, using hysteroscopic transillumination to delineate the supra-vesical isthmocele borders, the defect was excised to healthy margins. The endometrium was then closed using a 2-0 Monocryl barbed suture, and myometrium closed using 2-0 PDS unidirectional barbed suture in two layers. The patient was discharged home same day with an uncomplicated recovery.

Measurements and Main Results: The patient was able to conceive spontaneously 13 weeks post-op, resulting in an intrauterine pregnancy. Patient underwent a repeat low transverse cesarean section at 37 weeks’ gestation to a healthy newborn without complications.

Conclusion: This is the first reported case of combined excision of RPOC within an isthmocele and isthmoplasty after FET with postoperative spontaneous pregnancy.