The Transverse versus the Sagittal Approach in First-Trimester Uterine Artery Doppler Measurement.

The transverse approach at a bladder depth of less than 5 cm performed better than the sagittal approach in the measurement of first-trimester uterine arteries. It may, thus, may be useful as a complementary approach in cases in which there is difficulty obtaining measurements using the sagittal approach.