What is the recommended frequency of antepartum surveillance in patients at risk for Intrauterine Growth Restriction (IUGR)?

From the Guidelines

The recommended frequency of antepartum surveillance for patients at risk for intrauterine growth restriction (IUGR) is typically every 1-2 weeks, with serial ultrasounds for fetal growth assessment every 3-4 weeks, along with Doppler studies of umbilical artery blood flow, as suggested by the Society for Maternal-Fetal Medicine 1.

Key Considerations

• The frequency of antepartum surveillance should be individualized based on the severity of growth restriction, gestational age, and presence of additional risk factors such as preeclampsia, chronic hypertension, or other maternal comorbidities that may further compromise placental function.
• For mild IUGR with normal Doppler studies, twice-weekly testing is appropriate, while more severe cases with abnormal Doppler findings may require daily monitoring, as recommended by the Society for Maternal-Fetal Medicine 1.
• The surveillance regimen should be intensified if there are worsening Doppler parameters, oligohydramnios (amniotic fluid index <5 cm), or non-reassuring non-stress testing (NST) results, as suggested by the American College of Radiology 1.

Surveillance Schedule

• Initial assessment: every 1-2 weeks after diagnosis of IUGR, with serial ultrasounds for fetal growth assessment every 3-4 weeks, along with Doppler studies of umbilical artery blood flow.
• Mild IUGR with normal Doppler studies: twice-weekly testing.
• Severe IUGR with abnormal Doppler findings: daily monitoring.
• Intensified surveillance: if there are worsening Doppler parameters, oligohydramnios, or non-reassuring NST results.

Important Factors

• Gestational age: surveillance frequency may need to be adjusted based on gestational age, with more frequent monitoring as term approaches.
• Presence of additional risk factors: preeclampsia, chronic hypertension, or other maternal comorbidities may require more frequent monitoring.
• Fetal growth restriction severity: more severe cases may require more frequent monitoring, as suggested by the Society for Maternal-Fetal Medicine 1.

From the Research

Frequency of Antepartum Surveillance

The frequency of antepartum surveillance in patients at risk for intrauterine growth restriction (IUGR) is crucial for identifying and managing this condition.

• The management of IUGR has been dependent on antenatal biophysical testing and umbilical artery Doppler studies 2.
• A guideline for screening, diagnosis, and management of pregnancies affected with IUGR suggests a framework for identifying pregnancies at risk and implementing appropriate intervention 3.
• Antenatal surveillance may include ultrasonography, measurement of symphysis-fundus height, and umbilical artery Doppler impedance 4.

Antenatal Testing

Antenatal testing is essential for monitoring fetal well-being in pregnancies at risk for IUGR.

• Umbilical artery Doppler pulsatility index (UA PI) is used to assess fetal well-being, and a low UA PI (<5%) is not associated with improved neonatal outcomes compared to normal UA PI 5.
• Antenatal corticosteroid treatment may reduce perinatal morbidity and mortality associated with IUGR 4.
• The frequency and type of antenatal testing may vary depending on the individual patient's risk factors and fetal status 3, 6.

Management of IUGR

The management of IUGR involves a multidisciplinary approach, including obstetricians, neonatologists, and other healthcare professionals.

• Identification of risk factors and measurement of symphysis-fundus height are currently the screening standards for IUGR 4.
• Diagnosis is verified by ultrasonography, and accuracy of diagnosis may be improved by using customized fetal growth curves and 3-dimensional ultrasonographic evaluation 4.
• Prophylaxis with acetylsalicylic acid and heparin may reduce the incidence of growth restriction in specific groups at high risk 4.