Natural Conception with Elevated FSH Levels
Yes, natural conception can still occur in individuals with elevated Follicle-Stimulating Hormone (FSH) levels, although the probability may be reduced depending on the degree of elevation and other factors. 1, 2, 3
Understanding FSH and Fertility
Elevated FSH is typically considered a marker of diminished ovarian reserve (DOR) or testicular dysfunction, but it does not necessarily mean complete infertility:
- In women, FSH levels rise as ovarian reserve declines, but this primarily reflects a quantitative rather than qualitative decline in ovarian function 2
- Case reports document successful pregnancies in women with extremely high FSH levels (as high as 143 mIU/ml) 3
- In men, elevated FSH often indicates abnormal spermatogenesis but does not preclude fertility 4
Fertility Potential in Women with High FSH
Impact on Conception Chances:
- Women with elevated FSH can still conceive naturally, though success rates decline as FSH levels increase 2
- Even women with very high FSH levels have achieved pregnancy through natural conception 3
- Spontaneous resumption of menses might not accurately reflect fertility potential, as natural conception has been reported despite post-treatment amenorrhea and low anti-Müllerian hormone (AMH) levels 1
Age as a Critical Factor:
- Younger women (<35 years) with elevated FSH have significantly better live birth rates compared to older women with normal FSH 2
- A study showed that younger women with elevated FSH had a 21.2% live birth rate compared to 12.1% in older women with normal FSH 2
Cumulative Success Rates:
- The cumulative live birth rate after three cycles in younger patients with elevated FSH levels was reported to be 49.3% 2
Fertility Potential in Men with High FSH
- Men with FSH levels >4.5 IU/L show increased risk of abnormal semen parameters, particularly affecting sperm concentration and morphology 5
- Despite elevated FSH, many men maintain sufficient sperm production for natural conception 4
- The testosterone/FSH ratio may be a better predictor of semen quality than FSH alone 5
Practical Considerations
For Women:
- Contraception remains necessary even for those with elevated FSH or amenorrhea, as spontaneous conception can still occur 1
- The relationship between urinary FSH levels and natural fertility appears to be nonlinear, with both very low (<7 mIU/mg cr) and elevated (≥12 mIU/mg cr) levels potentially associated with reduced fertility 6
For Men:
- Even with abnormal semen parameters associated with high FSH, natural conception remains possible, though potentially at reduced rates 4, 5
Common Pitfalls to Avoid
Assuming infertility based solely on FSH levels: High FSH alone should not be used to exclude patients from attempting natural conception 2
Overlooking age as a factor: Age significantly impacts fertility potential even with elevated FSH 2
Neglecting contraception: Individuals with elevated FSH who do not desire pregnancy should still use contraception, as natural conception remains possible 1
Focusing only on FSH: Other markers like AMH and antral follicle count in women, or testosterone/FSH ratio in men, may provide additional insights into fertility potential 1, 5
Single test reliance: Repetitive FSH testing appears to be of little benefit in predicting fertility, as within-person variance is relatively low 6