title: Determinants of underage induced abortion--the 1987 Finnish Birth Cohort study.
abstract: BACKGROUND
  Although underage pregnancies often end in induced abortion, data on girls who undergo termination of pregnancy are lacking. Our aim was to identify determinants of underage induced abortion and compare them with those of childbirth.
  
  
  METHODS
  All girls born in 1987 in Finland surviving the perinatal period (n = 29 041) were included in the study and divided into three study groups: Girls undergoing induced abortion (n = 1041, 3.6%) or childbirth (n = 395, 1.4%) at <18 years of age and girls with no underage pregnancies (n = 27 605, 95.0%).
  
  
  RESULTS
  Shared risk factors of underage induced abortion and childbirth included early onset behavioral and emotional disorders [adjusted OR 1.9 (1.4-2.5) and 2.7 (95% CI 1.8-3.9)], a history of foster care [1.5 [1.1-1.9] and 3.0 [2.3-4.1)], and socioeconomic factors, including living in a family receiving income support [1.8 (1.5-2.1) and 3.4 (2.7-4.4)], respectively. Specific risk factors of underage induced abortion were psychoactive substance use disorders [2.2 (1.3-3.5)], having a mother who smoked during pregnancy [1.5 (1.3-1.8)] or had undergone induced abortion [1.8 (1.5-2.2)]. Coping with a chronic physical illness [0.7 (0.5-0.9)], and perinatal problems [0.6 (0.4-0.7)] were inversely associated with underage induced abortion.
  
  
  CONCLUSIONS
  The traditionally acknowledged determinants of underage childbirth played a less prominent role in induced abortion. Novel risk factors of underage induced abortion were found, including severe substance abuse and adverse maternal reproductive history, and should be addressed at all levels offering youth healthcare and social welfare services.
authors.affiliation: Department of Obstetrics and Gynecology, University of Helsinki and Kätilöopisto Hospital, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Suvi
authors.identifier: http://orcid.org/0000-0002-5212-5548
authors.initials: S
authors.lastname: Leppälahti
authors.affiliation: Department of Obstetrics and Gynecology, University of Helsinki and Kätilöopisto Hospital, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Oskari
authors.identifier: http://orcid.org/0000-0002-8671-130X
authors.initials: O
authors.lastname: Heikinheimo
authors.affiliation: THL, National Institute for Health and Welfare, Oulu, Finland.
authors.forename: Reija
authors.initials: R
authors.lastname: Paananen
authors.affiliation: THL, National Institute for Health and Welfare, Helsinki, Finland.
authors.forename: Päivi
authors.identifier: http://orcid.org/0000-0002-7223-4071
authors.initials: P
authors.lastname: Santalahti
authors.affiliation: THL, National Institute for Health and Welfare, Oulu, Finland.
authors.forename: Marko
authors.identifier: http://orcid.org/0000-0003-3634-3294
authors.initials: M
authors.lastname: Merikukka
authors.affiliation: THL, National Institute for Health and Welfare, Helsinki, Finland.
authors.forename: Mika
authors.identifier: http://orcid.org/0000-0001-8254-7525
authors.initials: M
authors.lastname: Gissler
mesh_terms: D000028:Abortion, Induced / Q000706:statistics & numerical data*; D000293:Adolescent; D015331:Cohort Studies; D005260:Female; D005387:Finland / Q000453:epidemiology; D005581:Foster Home Care / Q000523:psychology / Q000706:statistics & numerical data; D006801:Humans; D001523:Mental Disorders / Q000150:complications / Q000453:epidemiology / Q000503:physiopathology; D036801:Parturition; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology; D011253:Pregnancy in Adolescence / Q000517:prevention & control*; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology; D012959:Socioeconomic Factors
keywords: Abortion; epidemiology; induced; pregnancy in adolescence; reproductive health