All of the following mechanisms might account for a reduce-risk of upper genital tract infection in users of progestin - releasing lUDs, except:: (A) Reduced retrograde menstruation, (B) Decreased ovulation, (C) Thickened cervical mucus, (D) Decidual changes in the endometrium
Answer is B. Decreased ovulation does not protect from upper genital tract infection. Also it doesn't inhibit ovulation in all women. THE TEXTBOOK OF GYNAECOLOGY SHEILA BALAKRISHNAN SECOND EDITION PAGE NO 379