Correlation between Doppler flow patterns in growth-restricted fetuses and neonatal circulation

Area of Science:

• Perinatal Medicine
• Fetal Physiology
• Neonatal Circulation

Background:

• Fetal growth restriction (FGR) poses significant risks to neonatal outcomes.
• Prenatal assessment of fetal well-being is crucial for managing FGR.
• Doppler ultrasound parameters are commonly used to evaluate fetal circulation in FGR.

Purpose of the Study:

• To investigate the correlation between prenatal Doppler parameters in fetuses with suspected growth restriction and their neonatal circulatory status.
• To determine if specific Doppler indices predict postnatal circulatory changes.

Main Methods:

• Serial Doppler measurements of umbilical artery (UA) and middle cerebral artery (MCA) pulsatility index (PI) were performed in 43 fetuses with suspected FGR.
• Neonatal circulation was assessed using near-infrared spectroscopy (NIRS) for cerebral, renal, and splanchnic oxygenation.
• Calculated ratios included cerebroplacental ratio (CPR), cerebrorenal ratio (CRR), and cerebrosplanchnic ratio (CSR).
• Spearman's rank correlation was used to analyze associations between prenatal Doppler parameters and neonatal NIRS variables.

Main Results:

• Prenatal UA-PI correlated with renal fractional tissue oxygen extraction (FTOE) and CRR on Day 1 postpartum.
• Prenatal MCA-PI correlated with cerebral FTOE on Day 2 postpartum.
• Prenatal CPR correlated with CRR on Day 1 postpartum.
• Most significant correlations were observed in the early postpartum period (Days 1-3).

Conclusions:

• Low MCA-PI and CPR, indicative of fetal brain sparing, are associated with a lower CRR postnatally.
• This suggests that the brain-sparing effect observed in fetal circulation may persist in the neonatal period for up to 3 days.
• Prenatal Doppler parameters offer insights into neonatal circulatory adaptation in FGR.