NBCSN Nationally Certified School Nurse Practice Exam 2026 - Free School Nurse Certification Practice Questions and Study Guide

The birth control pill is recognized for having the lowest failure rate among the various contraceptive methods when used correctly. The effectiveness of hormonal contraceptives, like the birth control pill, is typically over 99% with perfect use, meaning that fewer than 1 in 100 women will become pregnant in a year if they take the pill consistently and as directed. This high level of effectiveness is attributed to the hormonal regulation of the reproductive cycle, which prevents ovulation, thickens cervical mucus to block sperm, and alters the uterine lining to prevent implantation.

In contrast, other methods have higher failure rates due to factors that can influence their effectiveness. The diaphragm and condom rely more heavily on correct and consistent use, which can lead to higher rates of unintended pregnancies if not used properly. Emergency contraception is intended for use after unprotected intercourse and is not a regular contraceptive method, hence its effectiveness is not comparable in terms of long-term use.