Effect of extended hormonal suppression in patients with adenomyosis undergoing embryo transfer

Adenomyosis is an estrogen-dependent uterine disorder increasingly recognized as a major cause of infertility and adverse obstetric outcomes, yet optimal medical preparation before embryo transfer (ET) remains uncertain. Adenomyotic lesions create a hyperestrogenic, inflammatory, and architecturally distorted uterine environment that may impair endometrial receptivity and increase miscarriage risk, compromising assisted reproductive technology (ART) success. This review summarizes current evidence on extended hormonal suppression in patients with adenomyosis undergoing <i>in vitro</i> fertilization and ET. We examine the rationale, protocols, and reproductive outcomes of ultra-long gonadotropin-releasing hormone agonist (GnRHa) regimens, intensified suppression with GnRHa plus aromatase inhibitors, levonorgestrel-releasing intrauterine systems, oral dienogest, and continuous combined oral contraceptives. Available data suggest that prolonged GnRHa pretreatment, particularly in freeze-all strategies with frozen ET, may improve implantation and reduce miscarriage, with additional benefit from deeper suppression in selected severe cases. Progestin-based approaches appear promising but remain less well studied, while combined oral contraceptives mainly provide symptom control. The review highlights the heterogeneity and methodological limitations of existing studies and underscores the need for well-designed trials to define the optimal regimen, duration, and patient selection criteria for extended hormonal suppression before ET in women with adenomyosis.