Pregnancy outcomes after hysteroscopic surgery in women with cesarean scar syndrome

Cesarean scar defect often causes postmenstrual abnormal uterine bleeding, dysmenorrhea, chronic pelvic pain, and infertility, which are collectively known as cesarean scar syndrome (CSS). Several studies have reported that hysteroscopic surgery can restore fertility in women with CSS. The study aimed to identify factors that influence subsequent pregnancy following hysteroscopic surgery. Therefore, we studied 38 women with secondary infertility due to CSS who underwent hysteroscopic surgery at Shiga University of Medical Hospital between July 2014 and July 2019. Our hysteroscopic procedure included inferior edge resection and superficial cauterization of the cesarean scar defect under laparoscopic guidance. Patients were followed up for 3 to 40 months after surgery. Surgery was successful in all cases and no complications were observed. Twenty-seven patients (71%) became pregnant (pregnant group), while 11 (29%) did not (non-pregnant group). Baseline characteristics of age, body mass index, gravidity, parity, previous cesarean section, presence of endometriosis, retroflex uterus, and preoperative residual myometrial thickness were not significantly different between the groups. However, the median residual myometrium thickness was significantly higher after surgery than before surgery in the pregnant group (1.9 [1.1-3.6] vs 4.9 [3.4-6.6] mm, P<0.0001), whereas this difference was not significant in the non-pregnant group. Of those who became pregnant, 85% conceived within 2 years of surgery. Although three pregnancies resulted in abortion and one is ongoing at the time of writing, 23 pregnancies resulted in healthy babies at 35-38 gestational weeks by scheduled cesarean sections with no obstetrical complications due to hysteroscopic surgery. The average birth weight was 3,076 g. Our findings support that hysteroscopic surgery is a safe and effective treatment for secondary infertility due to CSS. The thickness of the residual myometrium may be a key factor that influences subsequent pregnancy in women with CSS.