Which progesterone-only contraceptive method works PRIMARILY by thickening cervical mucus rather than inhibiting ovulation?

• A Depot medroxyprogesterone acetate (DMPA) 150 mg IM every 3 months
• B Progestogen-only pill (POP) with desogestrel 75 µg (Cerazette)
• C Etonogestrel implant (Nexplanon)
• D Levonorgestrel-releasing IUS (LNG-IUS, Mirena) ✓

Explanation

The LNG-IUS (Mirena) releases 20 µg/day levonorgestrel locally, which primarily acts by thickening cervical mucus and causing endometrial atrophy, rather than systemic ovulation inhibition (ovulation occurs in ~75–80% of cycles). DMPA and the etonogestrel implant work mainly by inhibiting ovulation. Cerazette (desogestrel 75 µg) also inhibits ovulation reliably in >97% of cycles, making it different from traditional POPs.

Reference: Shaw's Textbook of Gynaecology, 17th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.