title: Intraplacental villous artery resistance indices and identification of placenta-mediated diseases.
abstract: OBJECTIVE
  Placenta-mediated diseases (PMDs) including preeclampsia and fetal growth restriction are often characterized by shallow trophoblast invasion and incomplete spiral artery remodeling leading to impaired placental perfusion. In this context, umbilical artery (UA) Doppler can be used to detect high resistance to flow characteristic of very late-stage placental disease. We propose that evaluation of intraplacental villous artery (IPVA) resistance can provide earlier detection of increased resistance in placental flow.
  
  
  METHODS
  Seventy-five patients were recruited from the Ottawa Hospital. All had scans at 18 to 20, 28 and 34 weeks of gestation. IPVAs arising perpendicular to the chorionic plate in three regions (placental tips 4 cm away from cord insertion and within 1 cm from cord insertion) were sampled at each gestational age for resistance index (RI) and pulsatility index (PI). UA Doppler was also obtained from a free loop of cord. Pregnancy outcomes were collected from a chart review. Data were analyzed using SAS version 9.4 and standard statistic tests (mean±s.d., Student's t-test, mixed-effects modeling).
  
  
  RESULTS
  A total of 53 patients completed the study. Of these, 38 had normal pregnancy outcomes (controls) and 15 (cases) developed PMD (preeclampsia, n=8 and low birth weight/intrauterine growth restriction, n=7). Mean birth weight in the study group was 2482.1±518.85 g. At 18 to 20, 28 and 34 weeks gestation, the mean IPVA resistance indices in the control group were 0.86±0.16, 0.81±0.12 and 0.71±0.12 for PI and 0.57±0.07, 0.55±0.06 and 0.49±0.06 for RI, respectively. However, in the cases developing PMDs, the PIs were 1.09±0.17, 0.95±0.21 and 0.78±0.07 and RIs 0.66±0.07, 0.60±0.07 and 0.54±0.04, respectively (P<0.05). UA PI and RI Doppler did not differ between the groups as early as 18 to 20 weeks gestation.
  
  
  CONCLUSIONS
  Doppler measures of IPVA appear superior to UA in detecting early changes related to PMD. IPVA PI and RI Doppler may be useful in the early identification of patients at risk of PMD.
authors.affiliation: Department of Obstetrics and Gynecology and Newborn Care, Division of Maternal-Fetal Medicine, Obstetrics and Gynecology, University of Ottawa, The Ottawa Hospital, Ottawa, ON, Canada.
authors.forename: I
authors.initials: I
authors.lastname: Babic
authors.affiliation: Department of Obstetrics and Gynecology and Newborn Care, Division of Maternal-Fetal Medicine, Obstetrics and Gynecology, University of Ottawa, The Ottawa Hospital, Ottawa, ON, Canada.
authors.forename: Z M
authors.initials: ZM
authors.lastname: Ferraro
authors.affiliation: First Steps Fertility, Toronto, ON, Canada.
authors.forename: K
authors.initials: K
authors.lastname: Garbedian
authors.affiliation: Centre Hospitalier Universitaire de Sherbrooke, Department of Obstetrics and Gynecology, Sherbrooke, QC, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Oulette
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Ottawa, The Ottawa Hospital, Ottawa, ON, Canada.
authors.forename: C G
authors.initials: CG
authors.lastname: Ball
authors.affiliation: Department of Obstetrics and Gynecology and Newborn Care, Division of Maternal-Fetal Medicine, Obstetrics and Gynecology, University of Ottawa, The Ottawa Hospital, Ottawa, ON, Canada.
authors.forename: F
authors.initials: F
authors.lastname: Moretti
authors.affiliation: Department of Obstetrics and Gynecology and Newborn Care, Division of Maternal-Fetal Medicine, Obstetrics and Gynecology, University of Ottawa, The Ottawa Hospital, Ottawa, ON, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Gruslin
mesh_terms: D000328:Adult; D001724:Birth Weight; D001783:Blood Flow Velocity; D002823:Chorion / Q000000981:diagnostic imaging; D005260:Female; D005317:Fetal Growth Retardation / Q000000981:diagnostic imaging*; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D010920:Placenta / Q000098:blood supply*; D010922:Placenta Diseases / Q000175:diagnosis*; D011225:Pre-Eclampsia / Q000000981:diagnostic imaging*; D011247:Pregnancy; D011256:Pregnancy Outcome; D011446:Prospective Studies; D018615:Ultrasonography, Doppler, Color; D016216:Ultrasonography, Prenatal; D014469:Umbilical Arteries / Q000000981:diagnostic imaging*; D055815:Young Adult