Doppler Ultrasonography Findings Before and After Progesterone Therapy in Abortus Imminens

To evaluate the effect of vaginal micronised progesterone on uteroplacental haemodynamics in first-trimester pregnancies complicated by abortus imminens.

A descriptive study. Place and Duration of the Study: Department of Obstetrics and Gynaecology, University of Health Sciences, Bursa City Hospital, Bursa, Turkiye, from October to December 2024.

This retrospective study included 27 women with singleton first-trimester pregnancies diagnosed with abortus imminens. Patients received vaginal micronised progesterone 400 mg/day for 14 days. Uterine and spiral artery Doppler ultrasound (DUS) indices, including pulsatility index (PI) and resistive index (RI), were measured before treatment, at 48 hours, and on Day 14 post-treatment. A paired-samples t-test was used to compare DUS indices, analysed in SPSS (version 26.0).

The mean age of the mothers was 30.30 ± 5.36 years; the mean body mass index was 24.51 ± 3.55 kg/m2. Mean gestational age was 9.4 ± 3.5 weeks. Significant decreases were observed in the spiral artery PI and RI and the right uterine artery indices at Assessments 2 and 3 compared with the pre-treatment values. High intra-observer agreement was observed for the uterine arteries (p <0.0001). Clinical follow-up showed successful term live births in 24 (88.9%) patients, while late miscarriage occurred in 3 (11.1%).

Vaginal micronised progesterone therapy for first-trimester abortus imminens produces a rapid, significant reduction in uterine and spiral artery Doppler indices within 48 hours, persisting at 14 days, indicating acute and sustained improvement in uteroplacental perfusion.

Progesterone, Uteroplacental circulation, Doppler velocimetry, Abortus imminens, Vaginal progesterone.