Retrospective Analysis of Conception Rates After Tubal Flushing With Saline at Hysterosalpingo‐Contrast Sonography ( HyCoSy )

BACKGROUND: Hysterosalpingo-contrast sonography (HyCoSy) with saline tubal flushing is widely used for fallopian tube assessment, but evidence regarding fertility outcomes remains limited. This study aimed to quantify conception outcomes within 12 months following HyCoSy with saline tubal flushing and identify clinical factors associated with conception. METHODS: This retrospective observational study included individuals undergoing HyCoSy with saline tubal flushing at Pacific Radiology Canterbury between December 2013 and December 2023 with 12-month fertility follow-up. Primary outcomes were spontaneous and post-assisted reproductive technology (ART) conception within 12 months, livebirth or ongoing pregnancy and time to spontaneous conception. Multivariate logistic regression identified factors associated with conception, and time to conception was assessed using Kaplan-Meier analysis. RESULTS: Among 313 participants, 178 (56.9%) conceived within 12 months. Spontaneous conception occurred in 45.8% of participants not undergoing ART and 74.3% of those undergoing ART. Livebirth or ongoing pregnancy occurred in 42.2%. Median time to spontaneous conception was 3.0 months (IQR 1.9-7.0). Longer infertility duration (aOR 0.987/month, 95% CI: 0.976-0.998), unilateral versus bilateral tubal patency (aOR 0.49, 95% CI: 0.24-0.998), Māori/Pasifika ethnicity (aOR 0.26, 95% CI: 0.08-0.87) and Asian (aOR 0.36, 95% CI: 0.18-0.70) versus European ethnicity were associated with reduced odds of conception. DISCUSSION: Saline HyCoSy is a low-cost, non-radiating diagnostic investigation, with favourable spontaneous and ART conception outcomes observed in this cohort. These findings support its value in routine fertility assessment, whereas highlighting the importance of timely referral, tubal assessment and equitable access to fertility services.