Optimizing the first-line fertility treatment

Area of Science:

• Reproductive Medicine
• Sperm Analysis
• Assisted Reproductive Technologies

Background:

• Intrauterine insemination (IUI) is a common fertility treatment.
• Clomiphene citrate (CC) is frequently used for controlled ovarian stimulation in IUI cycles.
• Identifying optimal sperm parameters is crucial for maximizing IUI success rates.

Purpose of the Study:

• To establish sperm score thresholds for satisfactory clinical pregnancy rates (CPR) in CC-stimulated IUI cycles.
• To investigate the influence of ovarian response to CC on these sperm thresholds.
• To minimize confounding factors by focusing on women aged 35 years or younger.

Main Methods:

• Analysis of 1,194 CC/IUI cycles in women ≤35 years old.
• Evaluation of semen parameters including volume, concentration, motility, and morphology.
• Calculation of clinical pregnancy rates (CPR) based on different sperm thresholds.
• Stratification of analysis based on ovarian response to CC (number of dominant follicles and endometrial thickness).

Main Results:

• Semen volume, concentration, and motility significantly influenced CPR.
• Normal sperm morphology (≥4%) showed comparable CPR across different percentages.
• A threshold of total motile spermatozoa (TM) ≥20 × 10⁶ was associated with a significantly higher CPR (17.8%) compared to <20 × 10⁶ (4.6%).
• The TM threshold for satisfactory outcomes was lower (10 × 10⁶) in patients with an optimal CC response (≥2 dominant follicles, endometrium ≥7mm) versus suboptimal response (40 × 10⁶).

Conclusions:

• The ovarian response to CC superovulation dictates the necessary total motile spermatozoa (TM) threshold for successful IUI.
• Patients with TM below their respective threshold may require enhanced stimulation (e.g., gonadotropins) or alternative treatments like in vitro fertilization (IVF).
• These findings aid in personalized treatment strategies for infertility.