Oral Contraceptive Pills Versus Levonorgestrel-Releasing Intrauterine System for Niche-Related Abnormal Uterine Bleeding

After eligibility and consenting, participants were randomized in a 1:1 ratio using a computer-generated block randomization list (block size of six). Allocation concealment was maintained using sequentially numbered, opaque, sealed envelopes, which were opened after consent.

All participants had a transvaginal ultrasound-confirmed uterine niche ≥2 mm in depth. Residual myometrial thickness, niche depth, length, and width were assessed.

• OCP group: Participants received a monophasic combined oral contraceptive pill containing 0.03 mg ethinyl estradiol and 3 mg drospirenone (Technospiron® 0.03/3 mg, Technopharm, Egypt), taken for 21 days starting on day 2 of menstruation for six consecutive cycles.
• LNG-IUS group: Participants received a 52 mg levonorgestrel-releasing intrauterine system (Mirena®, Bayer, Oy Finland), inserted under transvaginal ultrasound guidance within the first three days of menstruation for 6 months.

Both treatments were provided free of charge. Participants could switch to the alternative method upon study completion. Because of the nature of the interventions, blinding was not feasible; hence, the trial was open-label. Assessments were performed at baseline and at 1, 3, and 6 months. Participants recorded:

• Number of days of postmenstrual/intermenstrual spotting
• Total bleeding duration per cycle
• Pelvic pain and dysmenorrhea scores (10-point visual analogue scale)
• Sexual well-being (FSFI-6 score)
• Treatment satisfaction (satisfied/very satisfied vs. other responses)
• Adverse events, complications, and reasons for discontinuation (including LNG-IUS expulsion) At 6 months, transvaginal ultrasonography was repeated to assess residual myometrial thickness, niche depth, length, and width.

Inclusion criteria

• women with at least one previous cesarean section.
• presenting with postmenstrual or intermenstrual bleeding for ≥3 consecutive cycles lasting ≥2 days, and a total bleeding duration >7 days per cycle.
• All participants had a transvaginal ultrasound-confirmed uterine niche ≥2 mm in depth.

Exclusion criteria

• pregnancy
• malignancy
• other identifiable causes of abnormal uterine bleeding
• abnormal cervical cytology
• cervicitis
• pelvic inflammatory disease
• endometrial polyps
• uterine fibroids
• contraindications to either combined oral contraceptive pill or levonorgestrel-releasing intrauterine system
• desire for pregnancy
• refusal to participate