title: Sonographic maturation of the placenta at 30 to 34 weeks is not associated with second trimester markers of placental insufficiency in low-risk pregnancies.
abstract: OBJECTIVE
  Advanced placental maturation (Grannum [G] grade 3) before term is associated with adverse perinatal outcomes associated with placental insufficiency. The nature and timing of the underlying pathology of this process is presently unclear. We hypothesized that advanced placental maturation at 30 to 34 weeks' gestation is not associated with established second trimester markers of severe placental dysfunction.
  
  
  METHODS
  In a cohort study of 1238 low-risk Caucasian women with singleton pregnancies who had sonographic assessment of placental maturation and fetal growth at 34 weeks, the results of maternal serum screening (MSS) and uterine artery Doppler (UtAD) flow studies at 16 weeks were related to adverse perinatal outcomes associated with placental insufficiency: antepartum hemorrhage, preeclampsia, preterm birth < 37 weeks, small for gestational age (< 10th percentile), or postnatal evidence of intrauterine growth restriction (IUGR; ponderal index < 5th percentile).
  
  
  RESULTS
  G1 was found in 127 women (10.3%), G2 was found in 18 women (1.5%), and no cases of G3 were observed. Advanced Grannum grading was significantly associated with IUGR (48 [4.4%] in G0, 9 [7.1%] in G1, 5 [27.8%] in G2; P < 0.001), but was dependent on smoking status. IUGR was not predicted by abnormal MSS or abnormal UtAD findings at either the second or third trimester ultrasounds.
  
  
  CONCLUSIONS
  G2 maturation at 30 to 34 weeks' gestation is associated with mild IUGR at delivery in low-risk women and with smoking. IUGR was not predicted by either second or third trimester markers of severe placental dysfunction. Future studies directly observing the placenta in the late third trimester may aid the elusive diagnosis of "late-onset" mild IUGR.
authors.affiliation: Department of Obstetrics and Gynaecology, Mount Sinai Hospital, Toronto ON.
authors.forename: Melissa G
authors.initials: MG
authors.lastname: Walker
authors.affiliation: Developmental Endocrinology Research Group, Institute of Child Health, University College London, London, UK.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Hindmarsh
authors.affiliation: Department of Obstetrics and Gynaecology, University College London Hospitals, London, UK; Department of Obstetrics and Gynaecology, Rotunda Hospital, Dublin, Ireland.
authors.forename: Michael
authors.initials: M
authors.lastname: Geary
authors.affiliation: Department of Obstetrics and Gynaecology, Mount Sinai Hospital, Toronto ON; Department of Obstetrics and Gynaecology, University College London Hospitals, London, UK.
authors.forename: John C P
authors.initials: JCP
authors.lastname: Kingdom
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood; D006063:Chorionic Gonadotropin / Q000097:blood; D015331:Cohort Studies; D005260:Female; D005317:Fetal Growth Retardation / Q000175:diagnosis / Q000209:etiology; D006785:Hospitals, University; D006801:Humans; D008131:London; D008875:Middle Aged; D010920:Placenta / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D010922:Placenta Diseases / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology*; D010927:Placental Insufficiency / Q000097:blood*; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology; D011262:Pregnancy Trimester, Second / Q000097:blood; D011263:Pregnancy Trimester, Third / Q000502:physiology; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology; D014463:Ultrasonography; D055988:Uterine Artery / Q000000981:diagnostic imaging; D055815:Young Adult; D000509:alpha-Fetoproteins / Q000032:analysis
chemical_list: D015415:Biomarkers; D006063:Chorionic Gonadotropin; D000509:alpha-Fetoproteins