What is the most appropriate management for an intrauterine growth‑restricted fetus at 25 weeks + 6 days gestation with persistent absent end‑diastolic flow in the umbilical arteries and an absent a‑wave in the ductus venosus?

Management of Early FGR with Absent End-Diastolic Flow and Abnormal Ductus Venosus at 25+6 Weeks

This fetus requires immediate tertiary-level multidisciplinary care with fetal medicine and neonatology input, intensive inpatient surveillance with computerized cardiotocography (cCTG) 1-2 times daily and Doppler assessment 2-3 times per week, administration of antenatal corticosteroids and magnesium sulfate for neuroprotection, and expectant management with close monitoring for further deterioration in ductus venosus waveforms or cCTG parameters that would trigger delivery.

Immediate Actions Required

Transfer and Consultation

• Transfer to tertiary center immediately with highest-level NICU capabilities 1
• Involve fetal medicine specialists and neonatology for multidisciplinary management 1
• This gestational age (25+6 weeks) falls into the "very preterm" category requiring subspecialty expertise 1

Hospitalization and Monitoring Protocol

• Admit for inpatient management 2
• Initiate cCTG monitoring at least 1-2 times daily to assess short-term variation (STV) 2
• Perform Doppler assessment 2-3 times per week of umbilical artery and ductus venosus 2

Immediate Pharmacologic Interventions

• Administer antenatal corticosteroids for fetal lung maturity (this pregnancy is <32 weeks) 2
• Give magnesium sulfate for neuroprotection (pregnancy <32 weeks) 2

Surveillance Strategy Based on TRUFFLE Evidence

The management approach at this gestational age is guided by the TRUFFLE trial, which demonstrated that timing of delivery based on late ductus venosus changes (absent or reversed a-wave) combined with cCTG-STV safety net resulted in 95% of infants being neurologically intact at 2 years 1. This was superior to delivery based on early DV changes (91%) or CTG-STV alone (85%) 1.

Key Monitoring Parameters

Ductus Venosus Assessment:

• Currently shows absent a-wave, which represents late DV changes indicating significant fetal compromise 1
• This finding is strongly associated with adverse fetal and perinatal outcomes before 32 weeks 3
• Abnormal DV waveforms (absent/reversed a-wave) are the strongest predictor of perinatal death and adverse outcomes 3

Umbilical Artery Status:

• Persistent absent end-diastolic velocity requires 2-3 times weekly Doppler 2
• Monitor for progression to reversed end-diastolic velocity, which would necessitate delivery consideration at 30-32 weeks 2

Computerized CTG:

• Monitor short-term variation using gestational age-specific thresholds 1
• The "safety net" STV threshold serves as a backup trigger for delivery 1

Delivery Timing Decision Algorithm

Continue Expectant Management If:

• DV a-wave remains absent but not reversed
• cCTG-STV remains above safety net threshold
• No progression to reversed end-diastolic velocity in umbilical artery
• No signs of acute fetal decompensation

Triggers for Delivery Consideration:

Immediate delivery indicated if:

• Reversed a-wave in ductus venosus develops 1
• cCTG-STV falls below safety net threshold 1
• Reversed end-diastolic velocity in umbilical artery develops (would indicate delivery at 30-32 weeks) 2

Planned delivery timing:

• If stable with persistent absent end-diastolic velocity: consider delivery from 30 weeks, recommend by 32-34 weeks 1, 2
• The SMFM guidelines recommend delivery at 33-34 weeks for FGR with absent end-diastolic velocity 2
• The BJOG guideline suggests considering delivery from 30 weeks with absent end-diastolic flow, with mandatory delivery by 34 weeks 1

Important Clinical Nuances

Divergence in Guidelines on Ductus Venosus Use

There is a notable contradiction between guidelines:

• SMFM 2020 states ductus venosus "should NOT be used for routine clinical management" 2
• BJOG 2024 strongly recommends using ductus venosus changes (specifically late DV changes) for timing delivery based on TRUFFLE trial evidence showing superior neurodevelopmental outcomes 1

Resolution: Given that the BJOG 2024 guideline is more recent and specifically addresses early FGR management based on the TRUFFLE trial's long-term neurodevelopmental outcomes, the ductus venosus findings should guide management in this case. The TRUFFLE study demonstrated that using late DV changes resulted in the best 2-year neurodevelopmental outcomes (95% neurologically intact) 1.

Prognostic Significance of Current Findings

• The combination of absent end-diastolic flow with absent DV a-wave at 25+6 weeks indicates severe placental insufficiency 3, 4
• Research shows abnormal DV waveforms are strongly associated with perinatal death (odds strongly increased) and adverse outcomes 3
• However, the TRUFFLE trial showed that waiting for late DV changes before delivery improved long-term neurodevelopmental outcomes despite a non-significant increase in perinatal mortality 1

Mode of Delivery

• Consider cesarean delivery based on the entire clinical scenario, particularly given the severe compromise and very preterm gestational age 2
• Cesarean delivery should be strongly considered for FGR with absent/reversed end-diastolic velocity 2

Common Pitfalls to Avoid

1. Premature delivery without appropriate surveillance: The absent a-wave alone at this gestation is not an automatic delivery indication; wait for reversed a-wave or cCTG deterioration 1

2. Outpatient management: This severity of compromise at this gestational age requires inpatient monitoring 2

3. Inadequate neuroprotection: Failure to administer magnesium sulfate <32 weeks significantly impacts long-term neurodevelopmental outcomes 2

4. Insufficient monitoring frequency: With absent end-diastolic velocity, Doppler must be performed 2-3 times weekly, not weekly 2

5. Ignoring the TRUFFLE evidence: The trial specifically showed that using late DV changes (reversed a-wave) rather than early changes (absent a-wave) as a delivery trigger resulted in better neurodevelopmental outcomes 1

Expected Latency and Outcomes

Research indicates that with absent end-diastolic velocity, the median time from diagnosis to delivery ranges from 0-35 days (median 8 days) 5. The latency is highly variable and depends on the rate of deterioration 5. Gestational age at delivery is the strongest predictor of outcomes 3, making each additional day in utero valuable if fetal status permits.

The overall perinatal death rate in the TRUFFLE cohort was 8% with a cerebral palsy rate of 1% 1, but outcomes were best in the group managed with late DV changes as the delivery trigger.

1, 2, 5, 3