Ultrasound Features and Outcomes of Assisted Reproductive Technology-Conceived Heterotopic Pregnancies.

Objective: To investigate ultrasound characteristics and pregnancy outcomes in heterotopic pregnancy (HP) following assisted reproductive technology (ART), specifically comparing in vitro fertilisation and embryo transfer (IVF-ET) and ovulation induction with intercourse. Methods: A retrospective analysis was conducted of 21 patients with HP treated at the Reproductive Medicine Centre, First Affiliated Hospital of Suzhou University (Jan 2017-Jan 2023). The patients were divided into intervention (IP, n = 11) and expectant management (EM, n = 10) groups. The treatment modality, ultrasound features and pregnancy outcomes were analysed using appropriate statistical tests with effect estimates and 95% confidence intervals (CIs). Multivariate logistic regression was performed to adjust for potential confounding factors. Results: The IP group demonstrated significantly lower vascular indices compared to the EM group (RI: 0.55±0.01 vs 0.61±0.04; PI: 0.85±0.06 vs 1.04±0.11; S/D: 2.23±0.09 vs 2.63±0.24; all P<0.05). The presence of free fluid strongly predicted intervention necessity (OR: 5.83; 95% CI: 1.08-31.42). Multivariate analysis identified two key predictors: decreased RI independently correlated with EM success (adjusted OR: 0.14 per 0.1 unit decrease; 95% CI: 0.03-0.62; P=0.01), while cornual implantation predicted higher pregnancy loss risk (adjusted OR: 3.42; 95% CI: 1.18-9.94). Treatment outcomes diverged significantly - the IP group had 2 miscarriages (18.2%) and 9 healthy term infants (37-42 weeks gestation) (81.8%), whereas all EM-managed patients delivered healthy term infants (37-42 weeks gestation) without complications. Conclusion: An HP diagnosis requires vigilance during initial vaginal ultrasound, and there is an increased need for repeat scans. Lower RI/PI/S/D values correlate with instability requiring intervention, whereas small masses without free fluid may permit EM with excellent outcomes. Clinicians should maintain high vigilance for ectopic pregnancy in patients receiving ART to enable early diagnosis and appropriate treatment selection (expectant vs surgical).