What is the average reduction in Follicle-Stimulating Hormone (FSH) levels after varicocele repair?

FSH Reduction After Varicocele Repair

After varicocele repair, FSH levels typically decrease, with significant reductions observed particularly in patients with higher-grade varicoceles, showing an average reduction that varies based on baseline levels and varicocele severity.

Hormonal Changes After Varicocelectomy

• FSH levels typically decrease after varicocele repair, with changes becoming evident after approximately 3-6 months (two spermatogenic cycles) 1
• The decrease in FSH levels parallels improvements in semen parameters, which also typically take 3-6 months to show enhancement 1
• The reduction in FSH is more pronounced in patients with higher-grade varicoceles (grade 3) compared to those with lower-grade varicoceles 2

Factors Affecting FSH Reduction

• Baseline FSH levels significantly influence the degree of reduction after varicocele repair:

  • Patients with elevated baseline FSH (>10.06 mIU/mL) show less significant reductions 3
  • Patients with baseline FSH levels <10.06 mIU/mL show more significant reductions and better outcomes in terms of sperm appearance in previously azoospermic men 3

• Varicocele grade correlates with FSH reduction:

  • Higher-grade varicoceles (grade 3) with testicular hypotrophy and grade 4 spermatic vein reflux show significantly higher baseline FSH levels and greater post-operative reductions 2
  • The post-operative/pre-operative ratio of sperm density is significantly higher in patients with higher-grade varicoceles, correlating with FSH reduction 4

Quantitative Changes in FSH

• In one study, the peak/base ratio of FSH after luteinizing hormone-releasing hormone (LH-RH) stimulation was significantly decreased after varicocelectomy (p = 0.007) 4
• Another study demonstrated that patients with grade 3 varicocele, testicular hypotrophy, and grade 4 spermatic vein reflux had higher baseline FSH levels and showed significant FSH reduction after surgery 2
• In hypogonadal patients (testosterone <280 ng/dL), there was a decrease in mean FSH level after varicocelectomy, though this decrease was not statistically significant in all studies 5

Clinical Implications

• FSH reduction after varicocele repair is associated with improved fertility outcomes:
  • The pregnancy rate in partners of varicocelectomized patients (60%) was significantly higher than in conservatively treated groups (28%) in long-term follow-up studies 4
  • In non-obstructive azoospermic men with varicocele, baseline FSH <10.06 mIU/mL predicted the appearance of ejaculated spermatozoa after treatment with 81.8% specificity and 83.3% sensitivity 3

Important Caveats and Considerations

• Treatment should be targeted to men with clinical varicoceles and abnormal semen parameters, as treatment of men with normal semen analysis or subclinical varicoceles is not recommended regardless of hormonal status 1
• FSH reduction may not be significant in all patients, particularly those with normal baseline testosterone levels (eugonadal patients) 5
• The European Association of Urology strongly recommends treating infertile men with clinical varicoceles and abnormal semen parameters to improve fertility rates 6
• Monitoring of hormonal parameters should continue for at least 3-6 months post-surgery, as improvements typically take up to two spermatogenic cycles to become evident 1