An Intrauterine Device Works to Prevent Pregnancy by _____

Question

An intrauterine device works to prevent pregnancy by _____.  
A) changing the pH of the uterus so sperm cannot live
B) changing the chemistry of the uterus so sperm cannot live
C) interfering with sperm movement or implantation
D) killing sperm
E) preventing ovulation

Accepted Answer

An intrauterine device (IUD) works by interfering with sperm movement or implantation. It prevents fertilization by either creating a hostile environment for the sperm or by stopping the fertilized egg from attaching to the uterus. An IUD does not change the pH or chemistry of the uterus, nor does it kill sperm or prevent ovulation (which is the primary mode of action for hormonal contraceptives such as the pill or the patch).