Superior mesenteric artery flow velocity waveforms in small for gestational age fetuses

Area of Science:

• Perinatal medicine
• Fetal ultrasonography
• Doppler velocimetry

Background:

• Small-for-gestational-age (SGA) fetuses face increased risks of adverse perinatal outcomes.
• Assessing fetal well-being in SGA pregnancies is crucial for timely intervention.
• Doppler ultrasonography of fetal arteries is a key tool in monitoring SGA fetuses.

Purpose of the Study:

• To analyze superior mesenteric artery (SMA) flow velocity waveforms in SGA fetuses.
• To compare the diagnostic contribution of SMA waveforms with middle cerebral artery (MCA) and umbilical artery (UA) waveforms in managing SGA fetuses.

Main Methods:

• Prospective study of 41 SGA fetuses using color Doppler ultrasonography.
• Acquisition of MCA, UA, and SMA flow velocity waveforms.
• Quantification of waveforms using pulsatility index (PI).
• Definition of poor perinatal outcome criteria.

Main Results:

• Abnormal PI detected in 22/41 fetuses for MCA, 26/41 for UA, and 17/41 for SMA.
• Abnormal UA and MCA waveforms correlated with increased rates of poor perinatal outcome.
• Increased SMA PI indicated elevated vascular resistance and reduced visceral perfusion in SGA fetuses.

Conclusions:

• Abnormal SMA PI in SGA fetuses suggests increased vascular resistance and reduced visceral perfusion.
• SMA waveform analysis provides information that is largely supported by MCA and UA waveform data.
• Current Doppler assessment of MCA and UA provides sufficient information for managing SGA fetuses.