title: Association of Doppler parameters with placental signs of underperfusion in late-onset small-for-gestational-age pregnancies.
abstract: OBJECTIVE
  To elucidate the association between Doppler parameters and histological signs of placental underperfusion in late-onset small-for-gestational-age (SGA) babies.
  
  
  METHODS
  Umbilical, fetal middle cerebral and uterine artery pulsatility indices and umbilical vein blood flow (UVBF), which had been recorded within 7 days prior to delivery, were analyzed from a cohort of SGA singleton pregnancies delivered after 34 weeks' gestation and confirmed as having a birth weight < 10(th) percentile by local standards. In each case, the placenta was histologically evaluated for signs of placental underperfusion using a hierarchical and standardized classification system. The independent association of the Doppler parameters with placental underperfusion was evaluated using logistic regression and decision tree analysis.
  
  
  RESULTS
  In 51 cases (53.7%), there were 61 placental histological findings indicative of placental underperfusion. These cases had a significantly higher incidence of Cesarean section for non-reassuring fetal status (52.1% vs 11.9%; P < 0.001) and neonatal metabolic acidosis at birth (21.6% vs 0%; P = 0.001). Significant and independent contributions to the presence of placental underperfusion lesions were provided by increased mean UtA pulsatility index (PI) (P = 0.018; odds ratio (OR) 2 (95% CI, 1.1-3.7)) and decreased UVBF normalized to estimated fetal weight (P = 0.027; OR 0.97 (95% CI, 0.95-0.99)). The combination of both parameters revealed three groups with differing risks for placental underperfusion: normalized UVBF > 82 mL/min/kg (risk 31.3%), normalized UVBF ≤ 82 mL/min/kg and mean UtA-PI ≤ 95(th) percentile (risk 65.5%), and normalized UVBF ≤ 82 mL/min/kg and UtA-PI > 95(th) percentile (risk 94.4%).
  
  
  CONCLUSIONS
  In late-onset SGA pregnancies, uterine Doppler and UVBF are surrogates for placental underperfusion. These findings facilitate phenotypic profiling of cases of fetal growth restriction among the general population of late-onset SGA babies.
authors.affiliation: Department of Maternal-Fetal Medicine, Institute Clínic of Gynecology, Obstetrics and Neonatology (ICGON), Hospital Clinic-IDIBAPS, University of Barcelona and Centre for Biomedical Research on Rare Diseases (CIBER-ER), Barcelona, Spain; Maternal-Fetal Unit, CEDIFETAL, Centro de Diagnóstico de Ultrasonido e Imágenes, CEDIUL, Barranquilla, Colombia.
authors.forename: M
authors.initials: M
authors.lastname: Parra-Saavedra
authors.forename: F
authors.initials: F
authors.lastname: Crovetto
authors.forename: S
authors.initials: S
authors.lastname: Triunfo
authors.forename: S
authors.initials: S
authors.lastname: Savchev
authors.forename: A
authors.initials: A
authors.lastname: Peguero
authors.forename: A
authors.initials: A
authors.lastname: Nadal
authors.forename: E
authors.initials: E
authors.lastname: Gratacós
authors.forename: F
authors.initials: F
authors.lastname: Figueras
mesh_terms: D001724:Birth Weight; D005260:Female; D005317:Fetal Growth Retardation / Q000473:pathology*; D006801:Humans; D020925:Hypoxia-Ischemia, Brain / Q000000981:diagnostic imaging / Q000473:pathology*; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D008297:Male; D010920:Placenta / Q000473:pathology*; D021041:Placental Circulation; D010927:Placental Insufficiency / Q000503:physiopathology*; D011247:Pregnancy; D011446:Prospective Studies; D018615:Ultrasonography, Doppler, Color; D016216:Ultrasonography, Prenatal; D014469:Umbilical Arteries / Q000000981:diagnostic imaging / Q000503:physiopathology*; D055988:Uterine Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*
keywords: Doppler; fetal development; fetal growth restriction; placenta; ultrasonography