title: [Maternal risks factors associated with pre-term childbirth].
abstract: Pre-term childbirth is birth before 37 weeks. The incidence in Mexico is approximately between 5 and 10% of all pregnancies and it constitutes one of the primary causes of morbidity and perinatal mortality.
  
  
  OBJECTIVE
  To determine the maternal risk factors associated with preterm childbirth in the General Regional Hospital 1 of the Instituto Mexicano del Seguro Social, Querétaro.
  
  
  METHODS
  A study of cases (A) and controls (B) was made from September 1st, 2001, to June 30th, 2002; group A: 138 patients who finished their pregnancy before the 37th week, group B: 138 patients whose pregnancy came to term. Chi2, Student t test, and the momios method were used for statistical analysis.
  
  
  RESULTS
  8910 obstetric events were attended in the study period of which 600 patients (6.73%) were pre-term. There was no significant statistical difference in the age, the pregnancy interruption process and pre-eclampsia-eclampsia variables. The factors associated with pre-term childbirth with meaningful difference (p < or = 0.05) were weight and maternal height, premature rupture membrane, cervicovaginitis, gravidic hyperemesis, urinary infection, and anemia.
  
  
  CONCLUSIONS
  The incidence of pre-term childbirth as well as its associated factors were similar to those found in literature except for the preeclampsia-eclampsia syndrome.
authors.affiliation: Unidad de Medicina Familiar 16, Instituto Mexicano del Seguro Social, Querétaro.
authors.forename: Juvenal
authors.initials: J
authors.lastname: Calderón Guillén
authors.forename: Genaro
authors.initials: G
authors.lastname: Vega Malagón
authors.forename: Jorge
authors.initials: J
authors.lastname: Velásquez Tlapanco
authors.forename: Régulo
authors.initials: R
authors.lastname: Morales Carrera
authors.forename: Alfredo Jesús
authors.initials: AJ
authors.lastname: Vega Malagón
mesh_terms: D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008423:Maternal Age; D009035:Mothers; D036801:Parturition; D011247:Pregnancy; D011248:Pregnancy Complications; D012307:Risk Factors