When is daily fetal monitoring recommended in high-risk pregnancies?

Daily Fetal Monitoring in High-Risk Pregnancies

Daily fetal monitoring with cardiotocography (CTG) is recommended only in specific severe high-risk scenarios: preeclampsia with absent or reversed end-diastolic flow in the umbilical artery before 34 weeks' gestation, or reversed end-diastolic flow before 30 weeks' gestation. 1

Standard Monitoring Frequency for High-Risk Pregnancies

For most high-risk pregnancies, weekly or twice-weekly fetal testing has become the standard practice, not daily monitoring. 1 The optimal interval remains uncertain, but this frequency balances detection of fetal compromise against false-positive results and unnecessary interventions. 1

Conditions Requiring Weekly or Twice-Weekly Testing

• Preeclampsia without severe fetal compromise: Twice-weekly monitoring with biophysical profile (BPP) or modified BPP (nonstress test plus amniotic fluid assessment) 1
• Gestational hypertension: Weekly to twice-weekly testing depending on severity and presence of fetal growth restriction 1
• Chronic hypertension: Weekly testing, increased to twice-weekly if superimposed preeclampsia or fetal growth restriction develops 1
• Diabetes mellitus: Weekly testing starting at 32 weeks for well-controlled gestational diabetes; earlier (26-28 weeks) for insulin-dependent diabetes with vascular complications or poor control 2, 3
• Fetal growth restriction with normal umbilical artery Doppler: Every 2 weeks for fetal biometry, weekly for amniotic fluid and Doppler assessment 1

Specific Indications for Daily Monitoring

Daily CTG monitoring is reserved for the most severe placental insufficiency scenarios where fetal decompensation can occur rapidly:

Absent End-Diastolic Flow Before 34 Weeks

• Daily cardiotocograph monitoring is mandatory 1
• Combine with twice-weekly umbilical artery Doppler and amniotic fluid volume assessment 1
• Daily discussion with consultant team required 1
• Delivery should be considered no later than 34 weeks' gestation 1

Reversed End-Diastolic Flow Before 30 Weeks

• Hospital admission with daily cardiotocograph monitoring is required 1
• Three times weekly umbilical artery Doppler and amniotic fluid assessment 1
• Fetal medicine specialist consultation to determine viability and guide management 1
• Delivery should be considered no later than 30 weeks' gestation 1

Monitoring Schedule for Fetal Growth Restriction

The frequency escalates based on Doppler findings:

• Normal umbilical artery Doppler: Fetal biometry every 2 weeks, amniotic fluid and Doppler weekly 1
• Increased resistance (pulsatility index >95th percentile): Weekly or more frequent surveillance 1
• Absent end-diastolic flow: Daily CTG as described above 1
• Reversed end-diastolic flow: Daily CTG with hospital admission 1

Timing to Initiate Surveillance

Initiation should be tailored based on the risk for stillbirth and likelihood of survival with intervention. 1

• Preeclampsia: Begin at diagnosis with initial comprehensive ultrasound assessment (fetal biometry, amniotic fluid, umbilical artery Doppler) 1
• Gestational hypertension: From 26 weeks' gestation, with 2-4 week intervals if fetal biometry normal 1
• Chronic hypertension without complications: From 26 weeks' gestation 1
• Diabetes with vascular complications (Class R or F) or growth restriction: As early as 26 weeks' gestation 2
• Well-controlled gestational diabetes: 32 weeks' gestation 2
• Fetal growth restriction: At time of diagnosis, but not before viability 1

Critical Limitations and Pitfalls

No antenatal testing can predict stillbirth related to acute changes in maternal-fetal status such as placental abruption or cord accident. 1 Even with intensive monitoring:

• Sudden fetal death can occur within 72 hours of reassuring testing in gestational diabetes despite euglycemia 4
• Three stillbirths occurred in well-monitored diabetic pregnancies with recent normal tests 4
• All antenatal tests have high negative predictive values but limited positive predictive values 1

Common pitfall: Over-reliance on a single normal test result in high-risk conditions. At least 25% of gestational hypertension cases progress to preeclampsia, which can occur rapidly. 5

Maternal Monitoring Components in Hypertensive Disorders

When fetal monitoring is indicated for hypertensive disorders, concurrent maternal surveillance is essential:

• Blood pressure monitoring: Target 110-140/85 mmHg; treat urgently if ≥160/110 mmHg 1, 5
• Laboratory tests: Minimum twice weekly for hemoglobin, platelets, liver transaminases, creatinine, and uric acid 1
• Clinical assessment: Proteinuria screening, neurological symptoms, clonus 1
• Magnesium sulfate: For seizure prophylaxis if severe hypertension or neurological symptoms develop 1, 5

Intrapartum Monitoring

Continuous electronic fetal heart rate monitoring is recommended during labor for all high-risk pregnancies, including those with controlled hypertension and fetal growth restriction. 5 This differs from antepartum surveillance and represents a separate indication for continuous rather than intermittent monitoring.