The goal of this observational study is to learn about how weight loss surgery (also called bariatric surgery) affects sexual function and sex hormone levels in women with severe obesity. It will also look at how the surgery affects mood, quality of life, body image, and the partner's sexual health.

The main questions it aims to answer are:

• Does sexual function improve after weight loss surgery?
• Do sex hormone levels change after weight loss surgery?
• Are these changes linked to improvements in mood and quality of life?
• Does the partner also experience changes in sexual function?

Researchers will compare each participant's results before surgery to their results 6 months after surgery. This helps show how things change over time.

This study will include about 40 women who:

• Are between 18 and 45 years old
• Have severe obesity and are scheduled for weight loss surgery at Cairo University Hospital
• Have a stable, sexually active partner relationship

What participants will do:

• Complete questionnaires about sexual function, mood, quality of life, and body image (twice: before surgery and 6 months after)
• Provide a blood sample to measure sex hormone levels (before surgery and 6 months after)
• Their partners will complete a short questionnaire about their own sexual function

This research is important because sexual health is a key part of quality of life that is often overlooked in obesity care. Understanding how weight loss surgery affects sexual function, hormones, and mood can help doctors better counsel patients about what to expect after surgery. This is one of the first studies in Egypt to examine these questions and the first to include partner assessment.

The study will start in January 2026. Results will be available by late 2026.

BACKGROUND:

Obesity is associated with significant physiological and psychological morbidity. While the metabolic effects of bariatric surgery are well-documented, its impact on female sexual health remains understudied, particularly in Middle Eastern populations. Sexual function is regulated by complex interactions between sex hormones (estrogen, testosterone, SHBG), psychological status (depression, anxiety), and body image. Obesity disrupts the hypothalamic-pituitary-gonadal axis through increased aromatase activity in adipose tissue, leading to hormonal imbalances. Weight loss following bariatric surgery may restore hormonal homeostasis and improve psychological well-being, potentially enhancing sexual function. However, the mediating pathways linking these changes have not been systematically examined.

OBJECTIVES:

Primary: To assess changes in female sexual function (FSFI scores) and sex hormone levels (total testosterone, free testosterone, estradiol E2, SHBG, and calculated Free Androgen Index) from baseline to 6 months after bariatric surgery.

Secondary: (1) To assess changes in depressive symptoms (Beck Depression Inventory-II) and anxiety symptoms (Beck Anxiety Inventory); (2) To assess changes in quality of life (Bariatric Quality of Life Index); (3) To assess body image satisfaction at 6 months; (4) To assess changes in partner sexual function (International Index of Erectile Function); (5) To explore mediating pathways linking weight loss, hormonal changes, mood improvement, and sexual function improvement;

METHODS:

Design: Prospective single-center observational cohort study. Setting: Department of General Surgery (Bariatric Surgery Unit), Kasr Al-Ainy Faculty of Medicine, Cairo University, Egypt.

Population: 40 morbidly obese female patients aged 18-45 years with stable, sexually active partner relationships, scheduled for primary bariatric surgery (sleeve gastrectomy or gastric bypass).

Procedures:

Eligible participants provide informed consent at baseline. Assessments occur at two time points: pre-operatively (within 2 weeks before surgery) and 6 months post-operatively.

At each assessment, participants undergo:

1. Clinical evaluation: height, weight, BMI, smoking history, marital status, menstrual history (cycle regularity, last menstrual period), medication review

2. Psychometric assessments:

   • Arabic Female Sexual Function Index (ArFSFI) - 19 items, 6 domains
   • Beck Depression Inventory-II (BDI-II) - 21 items
   • Beck Anxiety Inventory (BAI) - 21 items
   • Bariatric Quality of Life Index (BQL) - 30 items
   • Post-bariatric body image satisfaction questionnaire (6 months only)

3. Hormonal assessment: Fasting morning blood sample (8:00-11:00 AM) during luteal phase for measurement of total testosterone, free testosterone, estradiol E2, and SHBG using electrochemiluminescence immunoassay. Free Androgen Index (FAI) is calculated as (total testosterone [nmol/L] × 100)/SHBG [nmol/L].

4. Partner assessment: International Index of Erectile Function (IIEF) completed by partner

Significance:

This study will provide comprehensive, mechanistic insights into the multi-dimensional improvements in female sexual health following bariatric surgery. By including hormonal, psychological, and partner assessments, it addresses critical gaps in the literature and provides culturally-relevant data for Middle Eastern populations. Findings may inform pre-operative counseling and post-operative care for women undergoing bariatric surgery.

Inclusion Criteria:

• Female gender
• Age 18-45 years (childbearing period)
• Body Mass Index (BMI) ≥40 kg/m² or ≥35 kg/m² with obesity-related comorbidities, meeting international criteria for bariatric surgery
• Scheduled for primary bariatric surgery (sleeve gastrectomy or Roux-en-Y gastric bypass)
• Presence of a stable, sexually active intimate partner relationship
• Sexually active
• Willingness to participate and provide informed consent
• Ability to complete Arabic-language questionnaires

Exclusion Criteria:

• Women who are not sexually active
• Post-menopausal women (amenorrhea ≥12 months without other cause)
• Current pregnancy or lactation
• History of medication use that can interfere with sexual function, including:
• Antidepressants
• Antipsychotics/psychotropic drugs
• Beta-blockers
• Spironolactone
• Hormonal contraceptives (unless stable for ≥3 months and continued throughout study)
• Hormone replacement therapy
• Major uncontrolled medical conditions:
• Chronic heavy smoker (smoking index ≥400 pack-years)
• History of pelvic floor surgery or gynecological malignancy
• Partner with known erectile dysfunction or use of erectile dysfunction medications
• Previous bariatric surgery (revisional procedures)
• Inability or unwillingness to provide informed consent

Morbidly obese female patients of childbearing age (18-50 years) with stable, sexually active intimate partner relationships, scheduled for primary bariatric surgery (sleeve gastrectomy or Roux-en-Y gastric bypass) at Cairo University Hospital, Egypt. Participants are recruited from the bariatric surgery clinic during routine pre-operative assessment.