Obgyn · Year 3 · from Obgyn

Case 2: Intrauterine Growth Restriction with Abnormal Umbilical Artery Doppler

Patient Demographics

  • Age: 28 years
  • Sex: Female
  • Occupation: Accountant

Chief Complaint

"My doctor said the baby is measuring small and needs more testing."

History of Present Illness

The patient is G1P0 at 30 weeks gestation, referred from her primary OB for suspected intrauterine growth restriction. At her 28-week visit, fundal height measured 24 cm (4 cm below expected). Growth ultrasound confirmed estimated fetal weight below the 5th percentile. She is now presenting for Doppler evaluation and fetal surveillance.

Past Medical History

  • Chronic hypertension on labetalol 200 mg twice daily
  • Pre-pregnancy BMI 23 kg/m2

Physical Examination

  • BP: 142/92 mmHg (elevated from baseline 130/85)
  • Fundal height: 26 cm at 30 weeks
  • No edema, no hyperreflexia

Ultrasound Findings

Growth Parameters:

  • Estimated fetal weight: 1,050 grams (<3rd percentile for 30 weeks)
  • Abdominal circumference: <3rd percentile
  • Head circumference: 20th percentile
  • Femur length: 18th percentile
  • Pattern: Asymmetric IUGR (brain-sparing)

Amniotic Fluid:

  • AFI: 6 cm (low-normal)

Doppler Evaluation

Umbilical Artery:

  • S/D ratio: 4.8 (elevated, >95th percentile)
  • End-diastolic flow: PRESENT but reduced
  • Interpretation: Elevated placental vascular resistance

Middle Cerebral Artery:

  • Pulsatility index: Decreased (<5th percentile)
  • Interpretation: Cerebral redistribution (brain-sparing)

Cerebroplacental Ratio (CPR):

  • Calculated: 0.85 (abnormal, <1.0)

Ductus Venosus:

  • A-wave: Present and forward (normal)

Diagnosis

Severe Early-Onset IUGR with Abnormal Dopplers

  • EFW <3rd percentile (severe IUGR)
  • Asymmetric growth pattern
  • Elevated UA resistance with present end-diastolic flow
  • Evidence of fetal compensation (brain-sparing)
  • Associated with chronic hypertension with superimposed preeclampsia workup initiated

Management Plan

Immediate:

  • Admit for observation and maternal evaluation
  • Antenatal corticosteroids (betamethasone 12 mg IM x 2 doses)
  • Preeclampsia labs (CBC, CMP, LDH, uric acid, 24-hour urine protein)
  • Magnesium sulfate for neuroprotection given GA <32 weeks

Surveillance Protocol:

  • Twice-daily NST
  • Daily umbilical artery Doppler
  • BPP every other day
  • Ductus venosus Doppler daily

Delivery Timing Discussion:

  • Current status (abnormal UA with PRESENT end-diastolic flow): aim for 32-34 weeks
  • If ABSENT end-diastolic flow develops: 30-32 weeks
  • If REVERSED end-diastolic flow: delivery after steroids at current GA
  • If abnormal ductus venosus or BPP ≤6: delivery regardless of GA

Hospital Course

  • Preeclampsia labs confirmed superimposed preeclampsia (proteinuria 1.2 g/24 hours)
  • Day 3: Developed absent end-diastolic velocity on UA Doppler
  • Ductus venosus remained normal
  • Decision: Continue monitoring with plan for delivery at 32 weeks

Delivery

  • Cesarean delivery at 32 weeks 0 days
  • Male infant, 1,080 grams, Apgar 6/8
  • NICU admission for prematurity; stable course

Clinical Image

Image Description: Umbilical artery Doppler waveform showing elevated S/D ratio with present but reduced end-diastolic flow, indicating increased placental vascular resistance consistent with placental insufficiency in the setting of intrauterine growth restriction.

Attribution: Image from Radiopaedia. Educational case. Licensed under CC BY-NC-SA 3.0. Source: https://radiopaedia.org/articles/umbilical-artery-doppler

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