Cerebroplacental ratio
Pronunciation: ser-ee-bro-plah-SEN-tal
Also written as: CPR — Cerebroplacental ratio
Doppler measurement comparing fetal brain and placental blood flow to assess fetal adaptation to hypoxia.
Full Definition
The cerebroplacental ratio (CPR) is a Doppler ultrasound parameter calculated by dividing the middle cerebral artery pulsatility index by the umbilical artery pulsatility index. This ratio reflects fetal cardiovascular adaptation to placental insufficiency and chronic hypoxia, with decreased values indicating redistribution of blood flow to protect vital organs, particularly the brain. CPR provides earlier detection of fetal compromise than individual vessel assessments alone and helps identify fetuses at risk for adverse perinatal outcomes. Normal CPR values are gestational age-dependent, with values below the 5th percentile considered abnormal.
Usage
Usage note: Often abbreviated as CPR. Do not hyphenate when used as noun. Distinguish from cardiopulmonary resuscitation (CPR) through context.
In Context
- "The cerebroplacental ratio of 0.8 indicated fetal brain-sparing circulation due to placental insufficiency." — Doppler ultrasound report
- "Cerebroplacental ratio monitoring provides early detection of fetal compromise in growth-restricted pregnancies." — Research protocol