title: The effect of a sonographic estimated fetal weight on the risk of cesarean delivery in macrosomic and small for gestational-age infants.
abstract: OBJECTIVE
  To assess the association of a sonographic estimated fetal weight (sonoEFW) with the risk of cesarean delivery in women with macrosomic or small for gestational age (SGA) infants.
  
  
  METHODS
  Retrospective cohort of singleton deliveries >24 weeks by one MFM practice from 2005 to 2014. We included all patients who delivered an infant with macrosomia (birth weight ≥4000 g) or SGA (birth weight <10th percentile). We compared the risk of cesarean delivery between patients who did and did not have a sonoEFW within four weeks of delivery. Regression analysis was performed to control for any differences in baseline characteristics.
  
  
  RESULTS
  In patients with macrosomic infants (n = 352), the risk of cesarean delivery was significantly higher in the sonoEFW group (45.3% versus 17.6%, aOR 2.144, 95% CI: 1.06-4.34). When we restricted the analysis to the subgroup of 265 patients who attempted vaginal delivery, our results were similar (22.3% versus 9.1%, aOR 2.73, 95% CI: 1.15-6.48). In patients with an SGA infant (n = 614), the risk of cesarean delivery was not higher in the sonoEFW group (37.4% versus 24.1%, aOR 1.23, 95% CI: 0.80-2.07), nor in those who attempted vaginal delivery (19.8% versus 13.7%, aOR 1.17, 95% CI: 0.62-2.21).
  
  
  CONCLUSIONS
  A sonoEFW prior to delivery is independently associated with cesarean delivery in women with macrosomic infants, but not those with SGA infants. This should be considered when deciding to obtain a sonoEFW at the end of pregnancy, particularly if not for an accepted indication.
authors.affiliation: a Department of Obstetrics , Gynecology, and Reproductive Science, Icahn School of Medicine at Mount Sinai, Maternal Fetal Medicine Associates, PLLC , New York , NY , USA.
authors.forename: Kathy C
authors.initials: KC
authors.lastname: Matthews
authors.affiliation: a Department of Obstetrics , Gynecology, and Reproductive Science, Icahn School of Medicine at Mount Sinai, Maternal Fetal Medicine Associates, PLLC , New York , NY , USA.
authors.forename: John
authors.initials: J
authors.lastname: Williamson
authors.affiliation: a Department of Obstetrics , Gynecology, and Reproductive Science, Icahn School of Medicine at Mount Sinai, Maternal Fetal Medicine Associates, PLLC , New York , NY , USA.
authors.forename: Simi
authors.initials: S
authors.lastname: Gupta
authors.affiliation: a Department of Obstetrics , Gynecology, and Reproductive Science, Icahn School of Medicine at Mount Sinai, Maternal Fetal Medicine Associates, PLLC , New York , NY , USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Lam-Rachlin
authors.affiliation: a Department of Obstetrics , Gynecology, and Reproductive Science, Icahn School of Medicine at Mount Sinai, Maternal Fetal Medicine Associates, PLLC , New York , NY , USA.
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Saltzman
authors.affiliation: a Department of Obstetrics , Gynecology, and Reproductive Science, Icahn School of Medicine at Mount Sinai, Maternal Fetal Medicine Associates, PLLC , New York , NY , USA.
authors.forename: Andrei
authors.initials: A
authors.lastname: Rebarber
authors.affiliation: a Department of Obstetrics , Gynecology, and Reproductive Science, Icahn School of Medicine at Mount Sinai, Maternal Fetal Medicine Associates, PLLC , New York , NY , USA.
authors.forename: Nathan S
authors.initials: NS
authors.lastname: Fox
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002585:Cesarean Section / Q000523:psychology / Q000706:statistics & numerical data*; D005260:Female; D005320:Fetal Macrosomia / Q000000981:diagnostic imaging*; D020567:Fetal Weight / Q000502:physiology*; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D012044:Regression Analysis; D012189:Retrospective Studies; D012307:Risk Factors; D016216:Ultrasonography, Prenatal
keywords: Cesarean delivery; IUGR; estimated fetal weight; macrosomia; ultrasound