Decrease in high human chorionic gonadotropin in twin-twin transfusion syndrome following fetoscopic laser surgery.

Introduction: The purpose of this study was to investigate the concentration of maternal serum human chorionic gonadotropin (hCG) in twin-twin transfusion syndrome (TTTS) before and after fetoscopic laser surgery and to clarify the association between TTTS and hCG.

Material And Methods: The concentration of maternal serum hCG was measured before fetoscopic laser surgery and 2 and 4 weeks after laser surgery in 120 patients diagnosed with TTTS.

Results: The preoperative serum concentration of hCG was 6.34 multiples of the median (MoM; interquartile range 3.52-9.86). The concentration of hCG was higher in TTTS of Quintero stage III or IV (7.17 MoM, range 4.21-11.0) compared to stage I or II (3.37 MoM, range 2.35-7.74). When laser surgery for TTTS was effective, hCG gradually decreased to less than half the preoperative concentration 2 weeks after laser surgery, and the concentration was further reduced to within the normal range at 4 weeks. However, the concentration of hCG in 3 cases with TTTS recurrence did not decrease.

Discussion: A close association was observed between the concentration of hCG and the condition of TTTS. A change in the concentration of hCG after laser surgery could be a useful marker to judge the effectiveness of laser surgery in TTTS.