title: The relationship between vaginal bleeding in the first and second trimester of pregnancy and preterm labor.
abstract: BACKGROUND
  Vaginal bleeding is a common complication during pregnancy, which is observed in about 1/4 of pregnancies and in half of cases can lead to abortion. If vaginal bleeding happens during pregnancy some adverse pregnancy outcomes, including perinatal mortality and morbidity, low birth weight and preterm delivery will be increased.
  
  
  OBJECTIVE
  The aim of this study was to determine the relationship between vaginal bleeding and its characteristics in the first and second trimester of pregnancy and preterm labor.
  
  
  METHODS
  This is a case-control study conducted on 440 pregnant women referred to Al-Zahra Hospital in Rasht, Iran. Data were collected by a form. The form included demographic characteristics and confounding factors, the occurrence of bleeding during pregnancy and its features. Data were analyzed by T test, chi square and logistic regression in SPSS 16.
  
  
  RESULTS
  Findings showed that vaginal bleeding was associated with 3 times increased risk of preterm delivery (OR: 3, 1.84-4.89). Also, findings showed that bleeding characteristics including bleeding time, frequency, severity and intensity was significantly associated with preterm labor.
  
  
  CONCLUSIONS
  According to significant association between vaginal bleeding and preterm delivery, it seems that performing some interventions to prevent preterm labor could be appropriate.
authors.affiliation: Reproductive Health Research Center, Department of Obstetrics and Gynecology, Guilan University of Medical Sciences, Rasht, Iran.
authors.forename: Seyedeh Hajar
authors.initials: SH
authors.lastname: Sharami
authors.affiliation: Reproductive Health Research Center, Department of Obstetrics and Gynecology, Guilan University of Medical Sciences, Rasht, Iran.
authors.forename: Roya
authors.initials: R
authors.lastname: Faraji Darkhaneh
authors.affiliation: Reproductive Health Research Center, Department of Obstetrics and Gynecology, Guilan University of Medical Sciences, Rasht, Iran.
authors.forename: Ziba
authors.initials: Z
authors.lastname: Zahiri
authors.affiliation: Reproductive Health Research Center, Department of Obstetrics and Gynecology, Guilan University of Medical Sciences, Rasht, Iran.
authors.forename: Forozan
authors.initials: F
authors.lastname: Milani
authors.affiliation: Reproductive Health Research Center, Department of Obstetrics and Gynecology, Guilan University of Medical Sciences, Rasht, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Asgharnia
authors.affiliation: Guilan University of Medical Sciences, Rasht, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Shakiba
authors.affiliation: Guilan University of Medical Sciences, Rasht, Iran.
authors.forename: Zirak
authors.initials: Z
authors.lastname: Didar
keywords: Pregnancy; Preterm labor; Vaginal bleeding