Ultrasound-guided Lipiodol® hysterosalpingography: A prospective study on pregnancy and complication rates

BACKGROUND: Fluoroscopic hysterosalpingography (HSG) with Lipiodol® is safe and has a therapeutic effect on fertility: transient in endometriosis-related infertility and sustained in unexplained infertility. Ultrasound is replacing fluoroscopy as the preferred imaging modality for HSG due to comfort and radiation safety (no ionising radiation). The safety of ultrasound-guided Lipiodol® HSG is uncertain. AIMS: Prospectively observe pregnancy and complication rates after ultrasound-guided Lipiodol® HSG. MATERIALS AND METHODS: A single-centre prospective study of women with unexplained infertility undergoing ultrasound-guided Lipiodol® uterine bathing and tubal flushing after tubal patency confirmed with ExEm® Foam HyFoSy (hysterosalpingo-foam-sonography). Pregnancy outcomes at six months and serum and urinary thyroid function at one, three and eight weeks were recorded. Pain scores were recorded during and immediately after HSG. Descriptive statistics are reported. RESULTS: Fifty-two participants were enrolled between July 2019 and April 2021, median age 33 years (range 21-45). Only 45 (87%, 45/52) completed the Lipiodol® HSG; 5/7 experienced intravasation during initial HyFoSy. Of 30 women at follow-up, 57% had biochemical (17/30, 95% CI 37%-75%), 53% clinical (16/30 95% CI 34%-72%) and 35% ongoing pregnancies (11/30, 95% CI 20%-56%). The rate of subclinical hypothyroidism (SCH) at two months was 41% (7/17). One intravasation event occurred during Lipiodol® HSG (2%, 1/45). Median pain score was 5/10 (range 0-9, interquartile range 2.5-7). No anaphylaxis, infection or oil embolism was observed. CONCLUSION: Outpatient ultrasound-guided Lipiodol® HSG was safe, with pregnancy rates comparable to previous studies of fluoroscopic guidance. Rates of intravasation and SCH were also similar, confirming the need to monitor thyroid function.