title: [Causes of preterm delivery among adolescent mothers].
abstract: OBJECTIVE
  To describe the proportion of preterm delivery at pregnant adolescents clinic and their maternal, obstetric and fetal conditions other than spontaneous labor.
  
  
  METHODS
  Descriptive inside a cohort of consecutive cases. Preterm was defined from 20 to 36 full weeks. Maternal, obstetric and fetal conditions were defined if directly caused preterm labor or elective interruption; it was differentiated from spontaneous preterm labor.
  
  
  RESULTS
  Preterm delivery rate was 10.8% (252/2326): 0.8% from 20 to 27 weeks (19/2326), 3.3% from 28 to 33 weeks (77/2326) and 6.7% from 34 to 36 weeks (156/2326). Spontaneous preterm labor presented in 39.3% (99/252); main conditions found were: rupture of the membranes 18.7% (47/252), preeclampsia-eclampsia 10.3% (26/252), twin pregnancy 10.3% (26/252), intrauterine growth restriction 5.6% (14/252) and congenital defects 5.6% (14/252). They were classified as: obstetric-type 34.9% (887252), fetal 25.4% (64/252) and maternal 0.4% (1/252). There was a 40.5% rate of vaginal delivery (102/252), with the use of forceps in 1 out of 5.
  
  
  CONCLUSIONS
  At purpose-built clinics using evidence-based and problem oriented interventions, that are individually adapted and continuously up-dated, a non-risk comparable preterm delivery rate can be achieved at gestational ages with better neonatal prognosis.
authors.affiliation: Coordinación para la Atención de la Paciente Adolescente, Instituto Nacional de Perinatología Isidro Espinosa de los Reyes, colonia Lomas Virreyes, DF México. hoviedo77@hotmail.com
authors.forename: Héctor
authors.initials: H
authors.lastname: Oviedo Cruz
authors.forename: Josefina
authors.initials: J
authors.lastname: Lira Plascencia
authors.forename: Ayumi
authors.initials: A
authors.lastname: Ito Nakashimada
authors.forename: Juan Manuel
authors.initials: JM
authors.lastname: Grosso Espinoza
mesh_terms: D000293:Adolescent; D002585:Cesarean Section / Q000706:statistics & numerical data; D002648:Child; D015331:Cohort Studies; D000013:Congenital Abnormalities / Q000453:epidemiology; D036861:Delivery, Obstetric / Q000379:methods / Q000706:statistics & numerical data; D004461:Eclampsia / Q000453:epidemiology; D005260:Female; D005317:Fetal Growth Retardation / Q000453:epidemiology; D005322:Premature Rupture of Fetal Membranes / Q000453:epidemiology; D005865:Gestational Age; D006801:Humans; D008800:Mexico / Q000453:epidemiology; D007752:Obstetric Labor, Premature / Q000453:epidemiology / Q000209:etiology*; D011225:Pre-Eclampsia / Q000453:epidemiology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology; D011253:Pregnancy in Adolescence; D011272:Pregnancy, Multiple; D011295:Prenatal Care; D012307:Risk Factors