Hormonal therapies for post-abortion uterine recovery: Comparison of estradiol ± dydrogesterone, transdermal estradiol gel and combined oral contraceptives

Background: Induced abortion can impair endometrial repair, increasing risks for infertility. This study directly compared three hormonal regimens for enhancing post-abortion uterine recovery. Objectives: This study aimed to compare the efficacy and safety of different hormonal regimens on uterine recovery following surgically induced abortion. Methods: In this randomized controlled trial, 320 patients undergoing induced abortion at Leshan People's Hospital (May 2021 to January 2023) were allocated a computer-generated random number sequence into four groups (n=80 each): Group A received estradiol tablets/estradiol and dydrogesterone tablets, Group B received estradiol gel, Group C received drospirenone and ethiny lestradiol tablets (II) and Group D was a blank control. Primary outcomes included duration of vaginal bleeding, postoperative endometrial thickness, time to first menstruation and incidence of intrauterine adhesions and adverse events. Results: The duration of vaginal bleeding was significantly shorter in the treatment groups (Group A: 4 days [IQR 2-6]; Group B: 4 days [IQR 2-7]; Group C: 3 days [IQR 2-6.5]) compared to the control group (6 days [IQR 4-7]; P<0.05). Endometrial thickness was significantly greater in Group B (0.6 cm [IQR 0.5-0.8]) than in Groups A (0.5 cm [IQR 0.4-0.7]), C (0.4 cm [IQR 0.3-0.5]) and D (0.4 cm [IQR 0.4-0.6]; P<0.05). The time to menstrual resumption was shorter in Groups A (33 days [IQR 31-37]) and C (32 days [IQR 29-35]) compared to Groups B (36 days [IQR 33.5-42]) and D (38 days [IQR 35-44]; P<0.05). No significant differences were observed in postoperative infection or adhesion rates. The incidence of irregular bleeding was higher in Group C (44.4%) than in Group D (13.0%; P<0.05), but all adverse events were self-limiting. Conclusion: This study provides direct comparative evidence that specific hormonal regimens offer distinct benefits for post-abortion recovery. For women seeking contraception through drospirenone and ethinyl estradiol tablets are valuable for shortening bleeding and promoting menstrual regularity. For those with future fertility goals, estradiol gel is valuable for significantly enhancing endometrial regeneration. All regimens demonstrated good safety, enabling personalized clinical decision-making to improve patient outcomes after induced abortion.