The risk factors of miscarriage and obstetrical outcomes of intrauterine normal pregnancy following heterotopic pregnancy management

To investigate the clinical characteristics and risk factors for miscarriage of intrauterine normal pregnancy of patients with a heterotopic pregnancy (HP) after treatment. This was a retrospective study of medical records from CHA Bundang Medical Center. Sixty-four patients who were diagnosed with a HP between February 2006 and July 2017 were included in this study. All analyses were performed using SAS software, version 9.4 (SAS Institute, Inc., Cary, NC). P values < .05 were considered statistically significant. Forty-eight patients had tubal ectopic pregnancies (EP), 10 patients had cornual EPs, 1 patient had a cesarean section scar EP, 4 patients had an ovarian EP, and 1 patient had bilateral tubal EP. Among the 64 patients, 14.1% (9/64) miscarried before 10 weeks of gestation after management. Mean gestational age (GA) at treatment was 5.97 ± 0.50 weeks and 6.80 ± 1.04 weeks for miscarriage and nonmiscarriage group, respectively (P = .008). Significant differences were observed between 2 groups in terms of ultrasonographic features at the time HP was diagnosed (P = .040) Logistic regression models indicated that gestational age at treatment showed significant differences between 2 groups (OR: 0.003, 95% CI: 0.001–0.604). Immediate management after diagnosis could expect favorable prognosis of HP. GA at treatment was the only independent risk factor for miscarriage in patients with HP regardless of treatment methods.