Related Experiment Videos
Middle cerebral artery flow velocity waveforms in fetal hypoxaemia
S Vyas1, K H Nicolaides, S Bower
1Department of Obstetrics and Gynaecology, King's College Hospital, London, England.
British Journal of Obstetrics and Gynaecology
|September 1, 1990
Summary
Doppler studies in small-for-gestational age (SGA) fetuses reveal altered blood flow in the middle cerebral artery. Reduced pulsatility index (PI) indicates fetal hypoxemia, with rising PI potentially signaling brain edema.
Area of Science:
- Fetal Medicine
- Perinatology
- Doppler Ultrasound
Background:
- Small-for-gestational age (SGA) fetuses often experience placental insufficiency.
- Assessing fetal well-being in SGA pregnancies is crucial for timely intervention.
Purpose of the Study:
- To investigate fetal middle cerebral artery (MCA) blood flow patterns in SGA fetuses using Doppler ultrasound.
- To correlate MCA pulsatility index (PI) with fetal oxygenation levels.
Main Methods:
- Color flow imaging identified the MCA in 81 SGA fetuses.
- Pulsed Doppler studies measured impedance to flow (PI) and mean blood velocity.
- Fetal blood sampling (cordocentesis) assessed fetal hypoxemia (PO2).
Main Results:
- SGA fetuses showed significantly lower MCA PI and higher mean blood velocity than reference ranges.
- A quadratic relationship was found between fetal hypoxemia and MCA PI reduction.
- Maximum PI reduction occurred at 2-4 SD below normal PO2; higher oxygen deficit correlated with rising PI, suggesting brain edema.
Conclusions:
- MCA Doppler velocimetry is a valuable tool for assessing fetal compromise in SGA.
- Reduced MCA PI indicates fetal hypoxemia, while an increasing PI may suggest developing brain edema in SGA fetuses.