Determining the Rate of Oral Contraceptive Pills Failure in Unintended Pregnancies

Document Type : Original Article


1 Assistant Professor of Obstetrics & Gynecology, Women's Health Research Center, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran

2 Medical Student, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran


Introduction: Unintended pregnancy leads to unpleasant physical and psychological outcomes in both infant and mother. Unfortunately, many of these pregnancies are seen in women who use reliable contraceptive methods such as oral contraceptive pills. The aim of current study was to investigate the prevalence of oral contraceptive pills (OCP) in unintended pregnancies and the factors associated with its failure.
Methods: This descriptive-analytical study was conducted on 1000 pregnant women who referred to the obstetrics ward of Imam Reza hospital in Mashhad for labor from 2007 to 2008. A questionnaire was used for obtaining the demographics and type of contraception. Then mothers who had used oral contraceptive pills were asked for their applied methods. Data were analyzed by SPSS 11.5 software.
Results: 34.5% of studied women had unintended pregnancy that 3.91% had used contraceptive methods. The main method used in unintended pregnancies was OCP (40.3%). In OCP consumers, just 19.7% used OCP correctly. Fear of complications was the most prevalent cause of wrong use (42.2%). Other factors associated with OCP failure were age, education level and economic state which had significant relationship with failure (p<0.05).
Conclusion: Since OCP use is the most common contraception method and fear of complications is the most important cause of failure, training the correct method of OCP use and informing consumers about complications should be emphasized.


1. Cunningham FG, Leveno KJ, Bloom SL, Hauth JC, Gilstrap III LC, Wenstrom KD. Williams obstetrics. 22nd ed. New York McGraw­Hill;2005:725­50.
2. Stubblefeild  PG, Carr­Ellis S, Kapp  N. Family planning. In: Berek JS. Novak's  gynecology. 14th  ed. Philadelphia:Lippincott Williams & Wilkins;2007:247­312 .
3. Speroff L, Fritz MA. Clinical gynecologic endocrinology and  infertility. 7th  ed. Philadelphia:Lippincott
Williams & Wilkins;2005:861­942.
4. Geelhoed D, Nayembil D, Asare K, van Leeuwen JH, van Roosmalen J.  Gender and unwanted pregnancy: a community­based study in rural Ghana. J Psychosom Obstet Gynecol. 2002 Dec;23(4):249­55.
5. Leathers SJ, Kelley MA. Unintended pregnancy and depressive symptoms  among first­time mothers  and 
fathers. Am J Orthopsychiatry  2000 Oct;70(4):523­31.
6. Kost, K, Singh, S, Vaughan  B, Trussell J, Bankole A. Estimates of contraceptive failure from the 2002 
National Survey of Family Growth. Contraception 2008 Jan;77(1):10­21.
7. Hulsey TM, Laken M, Miller V, Ager J. The influence of attitudes about unintended pregnancy on use of
prenatal and postpartum care. J Perinatol. 2000 Dec;20(8 Pt 1):513­9.
8. Kasule  OH. Social and religious  dimensions of unwanted  pregnancy: an  Islamic perspective. Med  J 
Malaysia  2003 Mar;58 Suppl A:49­60.
9. Finer LB, Henshaw SK. Disparities in rates of unintended pregnancy in the United States, 1994 and 2001. Perspect Sex Reprod Health 2006 Jun;38(2):90­6.
10. Orr ST, Miller CA, James  SA, Babones S. Unintended pregnancy and  preterm birth. Pediatr Perinat
Epidemiol 2000 Oct;14(4):309­13.
11. Eggleston E, Tsui AO, Kotelchuck M. Unintended pregnancy and low birthweight in Ecuador. Am J Public  Health 2001 May;91(5):808­10.
12. Crosby RA, DiClemente  RJ,  Wingood  GM, Rosr E, Lang D. Correlates of unplanned and  unwanted 
pregnancy among African­American female teens. Am J Prev Med 2003 Oct;25(3):255­8.
13. Shaaban  OM, Glasier AF. Pregnancy during breastfeeding in  rural Egypt. Contraception  2008 
14. Gartner LM, Morton J, Lawrence RA, Naylor AJ, O'Hare D, Schanler RJ, et al. Breastfeeding and the use of human milk. Pediatrics 2005 Feb;115(2):496­506.
15. Myhrman  A, Olsen  P, Rantakallio P, Laara E. Does the  wantedness  of a  pregnancy predict a child's  educational attainment?. Fam Plann Perspect 1995 May­Jun;27(3):116­9.
16. Speroff L, Fritz MA. Clinical gynecologic endocrinology and  infertility. 7th  ed. Philadelphia:Lippincott
Williams and Wilkins;2008:61­942.
17. Faghihzadeh S, Babaee Rochee G, Lmyian  M,  Mansourian F, Rezasoltani P. Factors associated with  unwanted pregnancy. J Sex Marital Ther 2003 Mar­Apr;29(2):157­64.
18. Saberifard I, Safaian S, Khorashizadeh T. Processus program of contraception.1381:2­6. [In Persian]; کتاب است
19. Lete I, Bermejo R, Coll C, Dueñas JL, Doval JL, Martinez­Salmeán J, et al. Spanish population at risk of unwanted pregnancy: results of a national survey. Eur J Contracept Reprod Health Care. 2003 Jun; 8(2):75­9.
20. Cheng Y, Zhu W, Li Z, Zhang Y, Wang A. Contraceptive practices of women requesting termination of
pregnancy: a study erom china. Contraception. 1997 Jan;55(1):15­7.
21. Denton AB, Scott KE. Unintended and unwanted pregnancy in Halifax: the rate and associated factors. Can  J Public Health 1994 Jul­Aug;85(4):234­8.
22. Ministry of Education. Khorasan province jeography, second year of middle school. 1380:22. [In Persian] است کتاب
23. Rosenberg MJ, WaughMSm Long S. Unintended pregnancies and use, misuse and discontinuation of oral contraceptives. J Reprod Med 1995 May;40(5):355­60.
24. Burke AE, Blumenthal PD. Successful use of oral contraceptives. Semin Reprod Med 2001 Dec;19(4):313­21.
25. Saini M, Shuaib A. Stroke in women. Recent Pat Cardiovasc Drug Discov 2008 Nov;3(3):209­21.
26. Farhoosh MS. The way of contraception. 1374:54­5. [In Persian].است کتاب
27. Shufelt CL, Bairey Merz CN. Contraceptive hormone use and cardiovascular disease. J Am Coll Cardiol
2009 Jan 20;53(3):221­31.