title: Contraceptive failures in overweight and obese combined hormonal contraceptive users.
abstract: OBJECTIVE
  To estimate weather contraceptive failure rates among combined oral contraceptive pill (OCP), patch, and vaginal ring users was associated with increasing body mass index (BMI).
  
  
  METHODS
  Females enrolled in a large contraceptive study offering the reversible method of their choice at no cost were followed-up for 2-3 years. We compared the failure rates (pregnancy) among users of the OCP, transdermal patch, and contraceptive vaginal ring stratified by BMI.
  
  
  RESULTS
  Among the 7,486 participants available for this analysis, 1,523 chose OCPs, patch, or ring at enrollment. Of the 334 unintended pregnancies, 128 were found to be a result of OCP, patch, or ring failure. Three-year failure rates were not different across BMI categories (BMI less than 25 8.44%, 95% confidence interval [CI] 6.1-11.5; BMI 25-30 11.03%, 95% CI 7.5-16.0; BMI more than 30 8.92%, 95% confidence interval 7.6-11.5). Increasing parity (hazard ratio [HR] 3.06, CI 1.31-7.18) and history of a previous unintended pregnancy (HR 2.82, CI 1.63-4.87), but not BMI, were significant risk factors for unintended pregnancy.
  
  
  CONCLUSIONS
  Overweight and obese females do not appear to be at increased risk for contraceptive failure when using the OCP, patch, or vaginal ring.
authors: Division of Clinical Research, Department of Obstetrics and Gynecology, Washington University in St. Louis School of Medicine, St. Louis, Missouri.
authors: Colleen
authors: C
authors: McNicholas
authors: Qiuhong
authors: Q
authors: Zhao
authors: Gina
authors: G
authors: Secura
authors: Jenifer E
authors: JE
authors: Allsworth
authors: Tessa
authors: T
authors: Madden
authors: Jeffrey F
authors: JF
authors: Peipert
mesh_terms: D000279:Administration, Cutaneous; D000293:Adolescent; D000328:Adult; D015992:Body Mass Index; D003274:Contraceptive Devices, Female; D003277:Contraceptives, Oral, Combined; D005260:Female; D006801:Humans; D009765:Obesity; D050177:Overweight; D011247:Pregnancy; D049168:Pregnancy, Unplanned; D055815:Young Adult
chemical_list: D003277:Contraceptives, Oral, Combined
references: JAMA. 2010 Jan 20;303(3):235-41
references: 20071471
references: Contraception. 2011 Nov;84(5):478-85
references: 22018121
references: Fundam Clin Pharmacol. 1988;2(3):239-56
references: 3042569
references: Aust N Z J Obstet Gynaecol. 2012 Jun;52(3):270-6
references: 22694077
references: Am J Obstet Gynecol. 2010 Aug;203(2):115.e1-7
references: 20541171
references: Am J Epidemiol. 2007 Dec 1;166(11):1306-11
references: 17785712
references: Contraception. 2009 May;79(5):334-8
references: 19341843
references: Fertil Steril. 2012 Jul;98(1):109-16
references: 22607889
references: Obstet Gynecol. 2007 Nov;110(5):1050-8
references: 17978119
references: BJOG. 2012 Feb;119(3):283-90
references: 22168897
references: Contraception. 2008 Apr;77(4):234-8
references: 18342645
references: Obstet Gynecol. 2008 Sep;112(3):586-92
references: 18757656
references: Epidemiology. 2002 Mar;13(2):184-90
references: 11880759
references: Contraception. 2010 Jun;81(6):474-80
references: 20472113
references: J Obstet Gynaecol. 2010;30(7):679-86
references: 20925609
references: Am J Obstet Gynecol. 2009 Sep;201(3):263.e1-9
references: 19481720
references: N Engl J Med. 2012 May 24;366(21):1998-2007
references: 22621627
references: Ann Epidemiol. 2005 Aug;15(7):492-9
references: 16029841
references: Am J Obstet Gynecol. 2008 Jan;198(1):23-7
references: 18166298
references: Contraception. 2012 Mar;85(3):235-9
references: 22067763
references: Obstet Gynecol. 2005 Jan;105(1):46-52
references: 15625141
references: Obes Rev. 2011 May;12(5):e548-59
references: 21414129
references: Obstet Gynecol. 2010 Aug;116(2 Pt 1):275-283
references: 20664386
references: Am J Perinatol. 2009 May;26(5):345-9
references: 19067282
references: Clin Pharmacokinet. 2000 Sep;39(3):215-31
references: 11020136
references: World Health Organ Tech Rep Ser. 2000;894:i-xii, 1-253
references: 11234459
references: Cochrane Database Syst Rev. 2010 Jul 07;(7):CD008452
references: 20614470
references: Contraception. 2013 Aug;88(2):243-9
references: 22959396
references: Obstet Gynecol. 2005 Jun;105(6):1492; author reply1492-3
references: 15932865