Predicting Placental Pathologies by Ultrasound Imaging
Condition: Intrauterine Growth Restriction; Villitis; IUGR
MeSH terms: Fetal Growth Retardation
Study type: Observational

Summary: 
      Intrauterine growth restriction (IUGR) is caused when the placenta cannot provide enough
      nutrients to allow normal growth of the fetus during pregnancy. It is unclear why IUGR
      happens, but an increase in inflammatory T cells in the placenta known as villitis of unknown
      etiology (VUE) is observed in many IUGR infants. The investigators aim to develop ultrasound
      methods for diagnosing VUE to understand it's role in IUGR.
    

Detailed description: 
      Intrauterine growth restriction (IUGR) occurs in 3-10% of all pregnancies and is associated
      with significant morbidity and mortality during pregnancy, after birth and throughout the
      child's lifespan. IUGR is caused by the inability of the placental vasculature to provide
      enough oxygen and nutrients to support the fetus; yet, the mechanisms leading to disruption
      of placental vasculature are unknown. The placenta of ~50% of IUGR fetuses are infiltrated
      with inflammatory cells, specifically maternal T cells, which destroy placental blood vessels
      that support the fetus. This infiltration of T cells is known as villitis of unknown etiology
      (VUE). The diagnosis of VUE is problematic because it occurs without clinical signs and
      symptoms of maternal (or fetal) distress and puts the fetus at significant risk of demise.
      Additionally, VUE commonly recurs in subsequent pregnancies putting future offspring at risk.
      Yet, the exact prevalence of VUE and its significance in IUGR pathogenesis and outcomes are
      poorly understood as VUE is only diagnosed after the infant is outside the womb. Therefore,
      the study aims to recognize risk factors and cellular mechanisms associated with VUE and
      develop methods for diagnosing and treating VUE in utero, in order to improve infant health.
    

Intervention name(s): Comprehensive Doppler Ultrasound of the Placenta; Verasonics Ultrasound scanner (ultra-sensitive Doppler imaging)
Intervention type(s): Diagnostic Test; Other
Intervention description(s): Ultrasound measures to be collected include uterine artery (UtA) and umbilical artery (UA), systolic/diastolic (S/D) ratio, resistance index (RI), pulsatility index (PI) and presence of early diastolic notch.; In addition, a Verasonics ultrasound scanner will be used for ultra-sensitive Doppler imaging. Data will be collected on vessel density, periphery-to-center vessel density ratio (VDR) and microvessel morphology.
Observational model: Case-Control
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Participants will be recruited from women obtaining prenatal care in the obstetrics clinic
        at Mayo Clinic in Rochester, Minnesota. This study will consist of two cohorts: 1) women
        diagnosed with intrauterine growth restriction (IUGR) and 2) women having uncomplicated
        pregnancies. Forty women will be enrolled after being diagnosed with IUGR. Based on prior
        clinical data it is expected that 50% will have a VUE diagnosis. Another cohort of 20 women
        having uncomplicated pregnancies will also be enrolled, matched for fetal sex and
        gestational age at ultrasound.