A couple has been investigated for infertility. Post-coital test (PCT) shows < 5 motile sperm per high-power field in cervical mucus taken at mid-cycle. Semen analysis is normal. The next MOST appropriate investigation is:
- A Repeat PCT in next cycle
- B Hysteroscopy
- C Anti-sperm antibody testing ✓
- D Serum progesterone on Day 21
Correct answer: C. Anti-sperm antibody testing
Explanation
A poor PCT (< 5 motile sperm/HPF) with normal semen analysis raises suspicion of immunological infertility — anti-sperm antibodies (ASA) in cervical mucus or on sperm surface impair sperm-mucus penetration. ASA testing (SpermMar test or immunobead test) is the next logical step. Hysteroscopy is not indicated for cervical factor investigation. Day 21 progesterone confirms ovulation but does not address cervical factor. Repeating PCT without further investigation is low yield if the index test was performed correctly.
Reference: Shaw's Textbook of Gynaecology, 17th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.