title: Fetal macrosomia as a risk factor for shoulder dystocia during vacuum extraction.
abstract: OBJECTIVE
  Vacuum extraction of a macrosomic fetus is considered a risk factor for shoulder dystocia (SD). We evaluated maternal and fetal outcomes following vacuum extraction of macrosomic infants.
  
  
  METHODS
  A retrospective cohort study conducted in two large teaching hospitals. All deliveries of macrosomic infants by vacuum extraction and vaginal delivery were compared. The primary outcome measure was SD. Secondary outcome measures were severe perineal lacerations and postpartum hemorrhage. For statistical analysis, we used McNemar's test and χ2or Fisher's exact tests. Odds ratios were analyzed via a logistic regression model.
  
  
  RESULTS
  From 2003 to 2013, there were 6019 (5.45%) deliveries of macrosomic fetuses, and 230 (0.21%) were delivered by vacuum extraction. There were 23 (10%) and seven (3.04%) cases of SD in the study and control groups, respectively. The risk of SD was significantly higher in the study group (p > 0.05). We found a significant association between SD and vacuum delivery [p = 0.003; OR = 3.54 (95% CI: 1.49-8.42)]. The composite adverse neonatal outcome rate was 6.5% (15/230) and 1.7% (4/230) in the study and control groups, respectively (p = 0.009).
  
  
  CONCLUSIONS
  Vacuum extraction of a macrosomic infant is a risk factor for shoulder dystocia but not for postpartum hemorrhage or severe vaginal tears.
authors.affiliation: a Departments of Obstetrics and Gynecology , Hadassah-Hebrew University Medical Centers , Jerusalem , Israel.
authors.forename: Shmuel
authors.initials: S
authors.lastname: Herzberg
authors.affiliation: a Departments of Obstetrics and Gynecology , Hadassah-Hebrew University Medical Centers , Jerusalem , Israel.
authors.forename: Doron
authors.initials: D
authors.lastname: Kabiri
authors.affiliation: a Departments of Obstetrics and Gynecology , Hadassah-Hebrew University Medical Centers , Jerusalem , Israel.
authors.forename: Tzlil
authors.initials: T
authors.lastname: Mordechai
authors.affiliation: a Departments of Obstetrics and Gynecology , Hadassah-Hebrew University Medical Centers , Jerusalem , Israel.
authors.forename: Rani
authors.initials: R
authors.lastname: Haj Yahya
authors.affiliation: a Departments of Obstetrics and Gynecology , Hadassah-Hebrew University Medical Centers , Jerusalem , Israel.
authors.forename: Henry
authors.initials: H
authors.lastname: Chill
authors.affiliation: a Departments of Obstetrics and Gynecology , Hadassah-Hebrew University Medical Centers , Jerusalem , Israel.
authors.forename: Lorinne
authors.initials: L
authors.lastname: Levitt
authors.affiliation: a Departments of Obstetrics and Gynecology , Hadassah-Hebrew University Medical Centers , Jerusalem , Israel.
authors.forename: Hagai
authors.initials: H
authors.lastname: Amsalem
authors.affiliation: a Departments of Obstetrics and Gynecology , Hadassah-Hebrew University Medical Centers , Jerusalem , Israel.
authors.forename: Yossef
authors.initials: Y
authors.lastname: Ezra
mesh_terms: D000293:Adolescent; D000328:Adult; D001917:Brachial Plexus / Q000293:injuries; D015331:Cohort Studies; D036861:Delivery, Obstetric / Q000009:adverse effects; D004420:Dystocia / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D005320:Fetal Macrosomia / Q000150:complications*; D006801:Humans; D007557:Israel; D022125:Lacerations / Q000453:epidemiology; D010502:Perineum / Q000293:injuries; D006473:Postpartum Hemorrhage / Q000453:epidemiology; D011247:Pregnancy; D012189:Retrospective Studies; D012307:Risk Factors; D012782:Shoulder; D014620:Vacuum Extraction, Obstetrical / Q000009:adverse effects*; D055815:Young Adult
keywords: Macrosomia; shoulder dystocia; vacuum extraction