Heterotopic Interstitial Pregnancy: Early Ultrasound Diagnosis of 179 Cases After In Vitro Fertilization-Embryo Transfer

Objectives: What is the role of transvaginal sonography (TVS) in the early diagnosis of hectopic interstitial pregnancy (HIP) after in vitro fertilization-embryo transfer (IVF-ET)?

Methods: A retrospective observational study was conducted from January 2005 to December 2018. Routine two-dimensional and three-dimensional TVS were used to confirm clinical pregnancy. Women were diagnosed with HIP when an intrauterine gestational sac was combined with an extrauterine chorionic sac, which was at least 1 cm away from the uterine cavity and surrounded by a thin myometrial layer (<5 mm). Surgery and pathology results were the gold standard for diagnosing interstitial pregnancy. Non-surgical patients were excluded from the study. The performance of TVS and the pregnancy outcomes of intrauterine pregnancies (IUPs) were evaluated.

Results: A total of 97,161 women underwent IVF treatment and TVS examinations in our hospital during this study. Of these, 194 patients were diagnosed with HIP, with an incidence of 0.2% (194/97,161). Surgical and pathological findings confirmed 179 interstitial pregnancies, of which 174 were diagnosed by TVS, 4 were missed, and 1 was misdiagnosed. The sensitivity of TVS diagnosis was 97.8% and the positive predictive value was 99.4%. The mean time to diagnosis was 31 days after transplantation. One hundred and thirty-nine cases of HIP (77.7%) were diagnosed at the time of initial TVS examination. In 132 patients (73.7%), IUPs resulted in live births.

Conclusions: In our practice, most HIPs following IVF-ET can be accurately diagnosed by TVS, which facilitates early management of interstitial pregnancies and enables high live birth rates for IUPs.