What is the recommended management for a patient with a history of Intrauterine Growth Restriction (IUGR) in a previous pregnancy?

Management of Pregnancy with History of IUGR

For patients with a history of intrauterine growth restriction (IUGR) in a previous pregnancy, increased surveillance with serial ultrasounds and umbilical artery Doppler assessments should be implemented in subsequent pregnancies to monitor for recurrence and improve perinatal outcomes. 1

Risk Assessment and Recurrence Risk

• History of IUGR in a previous pregnancy increases risk of recurrence in subsequent pregnancies
• Recurrence rate is approximately 27.3% in women with previous early-onset severe IUGR 2
• Additional risk factors to assess:
  • Maternal age >40 years (increases IUGR risk) 3
  • Body mass index (BMI) extremes 3
  • Smoking status 3
  • Chronic medical conditions (hypertension, diabetes, autoimmune disorders) 1

Preventive Strategies

• Low-dose aspirin:

  • Should be started before 16 weeks gestation 3
  • Most effective when given in the second part of the day 3
  • Particularly indicated for women with prior IUGR <5th percentile due to placental dysfunction 3

• Additional preventive measures:

  • Optimize BMI before conception 3
  • Smoking cessation as early as possible 3
  • Stabilize chronic diseases that affect placental vascularization 3
  • Avoid multiple pregnancies when possible 3

Surveillance Protocol

First Trimester

• Early dating ultrasound
• Detailed medical history to identify additional risk factors
• Consider low-dose aspirin initiation before 16 weeks 3

Second Trimester

• Detailed anatomical survey ultrasound (CPT code 76811) 1
• Consider prenatal diagnostic testing with chromosomal microarray analysis (CMA) if early-onset IUGR (<32 weeks) occurs in current pregnancy 1

Third Trimester

• Serial growth ultrasounds every 3-4 weeks starting at 24-28 weeks

• Implement weekly umbilical artery Doppler assessments if IUGR is suspected or diagnosed 1

• Increase surveillance based on Doppler findings:

  • Normal umbilical artery Doppler: Weekly assessment 4
  • Decreased end-diastolic velocity or severe IUGR (EFW <3rd percentile): Weekly umbilical artery Doppler 1
  • Absent end-diastolic velocity (AEDV): Doppler assessment 2-3 times per week 1
  • Reversed end-diastolic velocity (REDV): Hospitalization with daily cardiotocography monitoring 1

• Weekly cardiotocography (CTG) testing after viability for IUGR without AEDV/REDV 1

• Increase CTG frequency when IUGR is complicated by AEDV/REDV 1

Delivery Timing

Timing of delivery should be based on umbilical artery Doppler findings and severity of growth restriction:

• Normal umbilical artery Doppler with EFW between 3rd-10th percentile: Deliver at 38-39 weeks gestation 1
• Decreased diastolic flow (without AEDV/REDV) OR severe IUGR (EFW <3rd percentile): Deliver at 37 weeks gestation 1
• Absent end-diastolic velocity (AEDV): Deliver at 33-34 weeks gestation 1
• Reversed end-diastolic velocity (REDV): Deliver at 30-32 weeks gestation 1

Additional Interventions

• Antenatal corticosteroids if delivery anticipated before 33 6/7 weeks or between 34 0/7 and 36 6/7 weeks in women at risk of preterm delivery within 7 days 1
• Magnesium sulfate for fetal and neonatal neuroprotection for pregnancies <32 weeks gestation 1
• Consider cesarean delivery for pregnancies with AEDV/REDV based on clinical scenario 1

Pitfalls and Caveats

• Distinguishing IUGR from constitutionally small fetuses is crucial, as not all small fetuses are pathologically growth restricted
• Early-onset IUGR (<32 weeks) is more likely associated with placental insufficiency and abnormal Doppler findings, requiring more intensive surveillance
• Close observation for 48-72 hours after corticosteroid administration is reasonable due to potential transient increased physiologic and metabolic demands 1
• Delivery decisions should be based on the combined analysis of gestational age, fetal heart rate analysis, and Doppler studies 5
• Women with previous early-onset IUGR without hypertensive disease still have significant risk for complications in subsequent pregnancies 2