It's estimated that as many as 13 out of 100 women who use the minipill will get pregnant in a year of use. The failure rate of the minipill is thought to be higher than that of other hormonal contraceptive methods. In addition, the minipill won't protect you from sexually transmitted infections.
If you become pregnant while taking the minipill, there appears to be a slightly higher chance that the pregnancy will be ectopic — when the fertilized egg implants outside the uterus, usually in a fallopian tube. However, there doesn't appear to be an increased risk of birth defects in babies born to women taking the minipill in pregnancy.
Side effects of the minipill may include:
Nov. 26, 2014
- Irregular menstrual bleeding
- Breast tenderness
- Decreased libido
- Ovarian cysts
- Weight gain or loss
- Hatcher RA, et al. Contraceptive Technology. 20th ed. New York, N.Y.: Ardent Media; 2011:249.
- Cunningham FG, et al. Williams Obstetrics. 23rd ed. New York, N.Y.: The McGraw-Hill Companies; 2010. http://www.accessmedicine.com/resourceTOC.aspx?resourceID=46. Accessed Sept. 27, 2014.
- Kaunitz AM. Progestin-only pills (POPs) for contraception. http://www.uptodate.com/home. Accessed Sept. 27, 2014.
- Espey E, et al. Effect of progestin vs. combined oral contraceptive pills on lactation: A double-blind randomized controlled trial. Obstetrics and Gynecology. 2012;119:5.
- Harms RW (expert opinion). Mayo Clinic, Rochester, Minn. October 16, 2014.