Analgesic Effect of TENS-WAA Combined With Tramadol Hydrochloride During Oocyte Retrieval Surgery

Inclusion Criteria: * Females aged between 21 and 42 years. * Patients diagnosed with infertility requiring oocyte retrieval for in vitro fertilisation-embryo transfer. * Body Mass Index (BMI) 18.5 ≤ BMI ≤ 29.9 kg/m². * Regular menstrual cycles with ultrasound monitoring demonstrating dominant follicle development and ovulation during the natural cycle; good ovarian reserve: follicle-stimulating hormone (FSH) \< 10 IU/L, antral follicle count (AFC) \> 6, anti-Müllerian hormone (AMH) \> 1.5 ng/ml. * Undergoing ovarian stimulation therapy using follicle-stimulating hormone (FSH) or gonadotropin protocols. * Electing tramadol hydrochloride injection for analgesia during oocyte retrieval. * Voluntary participation with signed written informed consent. Exclusion Criteria: * History of other chronic pain conditions, or prolonged use of opioid medications, history of anaesthetic drug addiction, or chronic alcohol abuse. * Severe pelvic adhesions. * Presence of pacemakers or other implanted medical electronic devices. * Concurrent use of high-frequency surgical equipment, artificial heart-lung machines, medical shortwave therapy, or microwave therapy devices. * Presence of scarring or skin lesions at electrode application sites. * Severe anxiety, depression, or other psychiatric conditions impairing accurate description of sensations, or any other disorders potentially affecting pain perception. * Conditions contraindicating or affecting oocyte retrieval, such as coagulation disor…