Doppler velocimetry in the fetus with a single umbilical artery

OBJECTIVE: To study Doppler velocimetry in fetuses with a single umbilical artery (SUA) as compared to normal. STUDY DESIGN: Private and clinic patients were referred to a perinatal cent er: 45 with SUA and 124 randomly selected fetuses with a three-vessel cord were studied from 18 to 41 weeks' gestation. Color Doppler flow ann energy were utilized to evaluate the umbilical arteries at fetal abdominal wall as well as the course around the bladder. In addition to Doppler velocimetry, an anatomic survey, estimated fetal weight (EFW) and amniotic fluid index (AFI) were assessed at each examination. RESULTS: Doppler velocimetry in SUA demonstrated indices in the normal rang e but lower than in normal cords from 26 weeks until near term. Anatomic ab normalies were found in 8.9% of SUA as compared to 4.8% for three-vessel co rds. Intrauterine growth restriction (IUGR) tons seen in four cases of SUA and none in the control group. EFW and AFI for both groups were virtually i dentical. CONCLUSION: SUA corns theoretically carry a normal blood volume, and the de creased resistance to flow, and larger arterial diameter allow, this to occ ur. Anomalies and IUGR are elevated in infants with SUA. Overall, EFW and A FI were the same in both groups of patients.