A couple has unexplained infertility for 2 years. Semen analysis: volume 2.5 mL, count 18 million/mL, total motility 40%, morphology 3% normal forms (strict Kruger criteria). The morphology result:
- A Is normal — WHO reference limit is 2%
- B Is normal — Kruger strict criteria lower limit is 5%
- C Is borderline — WHO 2021 lower reference limit is 4%; 3% is below normal ✓
- D Is severely abnormal (teratozoospermia cutoff is 14%)
Correct answer: C. Is borderline — WHO 2021 lower reference limit is 4%; 3% is below normal
Explanation
The WHO 2021 (6th edition) semen analysis reference values set the 5th centile lower reference limit for normal morphology at 4% using strict Kruger criteria. A value of 3% is therefore below the lower reference limit, indicating teratozoospermia. The WHO 2010 (5th edition) also set 4% as the lower limit. Earlier texts cited 2% which is outdated. This morphology result is abnormal and contributes to unexplained infertility.
Reference: Shaw's Textbook of Gynaecology, 17th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.