title: A Review of Hormonal Contraception and Venous Thromboembolism in Adolescents.
abstract: BACKGROUND
  The number of adolescents who are prescribed hormonal contraception (HC) for contraceptive and noncontraceptive indications is increasing. Approximately 1 of 4 female adolescents will use some form of HC by age 19 years. Venous thromboembolism (VTE) is a rare, but life-threatening complication associated with HC use. Although adolescents aged 15 to 19 years have the lowest absolute HC-associated VTE risk, they still account for 5.9% of HC-associated VTE. The absolute HC-associated VTE risk for those younger than 15 years of age is not well described.
  
  
  OBJECTIVE
  The objectives of this report are to describe the current literature regarding HC-associated VTE in adolescents, to review the coagulation cascade and in vivo coagulation, to highlight differences between the adolescent and adult coagulation profiles, to discuss coagulation profile changes related to HC use, and to identify knowledge deficits for future study.
  
  
  CONCLUSIONS
  The mechanisms and confounding variables that lead to HC-associated VTE in all adolescents are not well understood because many large HC studies exclude female adolescents younger than 18 years of age. Because of the paucity of data in this age group, observational studies and randomized controlled trials of VTE risk in adolescents on varying forms of HC are needed. Studies should include female adolescents across the entire adolescent age span (12-21 years) to better understand HC-associated VTE risk in this population.
authors: Nationwide Children's Hospital, Hematology/Oncology/BMT Division, Columbus, Ohio.
authors: Gary M
authors: GM
authors: Woods
authors: Nationwide Children's Hospital, Hematology/Oncology/BMT Division, Columbus, Ohio; The Ohio State University, Department of Pediatrics, Columbus, Ohio.
authors: Bryce A
authors: BA
authors: Kerlin
authors: Nationwide Children's Hospital, Hematology/Oncology/BMT Division, Columbus, Ohio; The Ohio State University, Department of Pediatrics, Columbus, Ohio.
authors: Sarah H
authors: SH
authors: O'Brien
authors: The Ohio State University, Department of Pediatrics, Columbus, Ohio; Nationwide Children's Hospital, Adolescent Medicine Division, Columbus, Ohio. Electronic address: andrea.bonny@nationwidechildrens.org.
authors: Andrea E
authors: AE
authors: Bonny
mesh_terms: D000293:Adolescent; D015986:Confounding Factors, Epidemiologic; D003267:Contraception / Q000706:statistics & numerical data; D003278:Contraceptives, Oral, Hormonal / Q000009:adverse effects*; D005260:Female; D006801:Humans; D012307:Risk Factors; D054556:Venous Thromboembolism / Q000139:chemically induced / Q000453:epidemiology*; D055815:Young Adult
chemical_list: D003278:Contraceptives, Oral, Hormonal
keywords: Adolescent; Coagulation; Hormonal contraception; Venous thromboembolism