title: Anterior placental location influences onset and progress of labor and postpartum outcome.
abstract: BACKGROUND
  The aim of the study is to evaluate whether placental location at term is associated with delivery outcome.
  
  
  METHODS
  A prospective study including 2354 patients with singleton pregnancy at term admitted for vaginal delivery was conducted. Placental position was determined before delivery by ultrasonographic examination performed transabdominally with women in the supine position. Maternal characteristics and delivery outcome such as premature rupture of membranes, induction of labor, mode and gestational age at delivery, indication for cesarean section, duration of the third stage, postpartum hemorrhage (PPH) and manual removal of placenta were correlated with anterior, posterior or fundal placental locations.
  
  
  RESULTS
  Among women enrolled: i) 1164 had an anterior placenta, ii) 1087 a posterior placenta, iii) 103 a fundal placenta. Women with anterior placenta showed: i) a higher incidence of induction of labor (p = 0.0001), especially for postdate pregnancies and prolonged prelabor rupture of membranes (p < 0.0001), ii) a higher rate of cesarean section rate for failure to progress in labor (p = 0.02), iii) a prolonged third stage (p = 0.01), iv) a higher incidence of manual removal of placenta (p = 0.003) and a higher rate of PPH in vaginal deliveries (p = 0.02).
  
  
  CONCLUSIONS
  The present study showed the influence of anterior placental location on the course of labor, with a later onset of labor, a higher rate of induction and cesarean section and postpartum complications. The reason for this influence on labor and delivery complications remains to be elucidated.
authors.affiliation: Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Torricelli
authors.affiliation: Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Vannuccini
authors.affiliation: Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy.
authors.forename: I
authors.initials: I
authors.lastname: Moncini
authors.affiliation: Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Cannoni
authors.affiliation: Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Voltolini
authors.affiliation: Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy.
authors.forename: N
authors.initials: N
authors.lastname: Conti
authors.affiliation: Department of Health Sciences, University of Florence, Florence, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Di Tommaso
authors.affiliation: Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy.
authors.forename: F M
authors.initials: FM
authors.lastname: Severi
authors.affiliation: Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy. Electronic address: felice.petraglia@unisi.it.
authors.forename: F
authors.initials: F
authors.lastname: Petraglia
mesh_terms: D000328:Adult; D002585:Cesarean Section / Q000009:adverse effects; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000453:epidemiology / Q000209:etiology / Q000628:therapy; D005865:Gestational Age; D006785:Hospitals, University; D006801:Humans; D015994:Incidence; D007558:Italy / Q000453:epidemiology; D007751:Labor, Induced / Q000009:adverse effects; D007744:Obstetric Labor Complications / Q000453:epidemiology / Q000209:etiology* / Q000628:therapy; D010920:Placenta / Q000000981:diagnostic imaging*; D006473:Postpartum Hemorrhage / Q000453:epidemiology / Q000209:etiology / Q000628:therapy; D011247:Pregnancy; D011256:Pregnancy Outcome; D065170:Pregnancy, Angular / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy; D011273:Pregnancy, Prolonged / Q000453:epidemiology / Q000209:etiology / Q000628:therapy; D011446:Prospective Studies; D016216:Ultrasonography, Prenatal; D055815:Young Adult
keywords: Labor; Myometrium; Placenta location; Postpartum; Ultrasound