OBJECTIVES: Our objectives were two-fold: 1) to determine the frequency of discordant umbilical artery Doppler systolic to diastolic (S/D) ratios in the individual umbilical arteries of growth-restricted fetuses and 2) to examine the impact of the frequency of discordance on clinical outcomes. METHODS: This was a prospective, observational study of growth-restricted fetuses. Doppler velocimetry was performed weekly and two S/D ratios were obtained for each fetal umbilical artery. Inter-artery discordance was defined as a difference in measurement categories (i.e., normal, elevated, absent, reversed) between the arteries. The number of abnormal measurements per visit was summed to 0-4 out of 4 values. A composite average number of abnormal Doppler measurements was calculated and fetuses were stratified based on degree of average number of abnormalities in increments of 25%: 0-<25%, 25-<50%, 50-<75%, and 75-100% abnormality. RESULTS: Of a total 241 fetuses (1762 visits), 110 (45.6%) had abnormal UAD flow and 189 (66%) demonstrated discordance. Abnormal values were noted in only one artery in 53% (n=151) of visits. Fetuses with any abnormal Doppler testing had smaller birthweights compared to fetuses with consistently normal testing (2485g vs 2623g, p <0.01); birthweight decreased as composite average of abnormal measurements increased (p = 0.03). CONCLUSION: The majority (66%) of fetuses with abnormal testing demonstrated UAD discordance. Up to 53% of fetuses could have been misdiagnosed if only one artery was tested. Fetuses with a higher frequency of Doppler abnormalities had lower birthweights. We propose obtaining two measurements from each umbilical artery in growth-restricted fetuses.
1. American College of Obstetricians and Gynecologists. ACOG practice bulletin 134: Fetal growth restriction. Obstet Gynecol. 2013;121(5):1122-1133.
2. Society for Maternal-Fetal Medicine Publications Committee, Berkley E, Chauhan SP, Abuhamad A. Doppler assessment of the fetus with intrauterine growth restriction. Am J Obstet Gynecol. 2012;206(4):300-308.
3. Baschat AA. Doppler application in the delivery timing of the preterm growth-restricted fetus: Another step in the right direction. Ultrasound Obstet Gynecol. 2004;23(2):111-118. doi:
7. Spong CY, Mercer BM, D’alton M, Kilpatrick S, Blackwell S, Saade G. Timing of indicated late-preterm and early-term birth. Obstet Gynecol. 2011;118(2 Pt 1):323-333 [Review, Guideline].
8. Predanic M, Kolli J, Yousefzadeh P, Pennisi J. Disparate blood flow patterns in parallel umbilical arteries. Obstet Gynecol. 1998;91(5 Pt 1):757-760.
9. Predanic M, Perni SC. Antenatal assessment of discordant umbilical arteries in singleton pregnancies. Croat Med J. 2006;47(5):701-708.
10. Dolkart LA, Reimers FT, Kuonen CA. Discordant umbilical arteries: Ultrasonographic and doppler analysis. Obstet Gynecol. 1992;79(1):59-63.
11. Hadlock FP, Harrist RB, Sharman RS, Deter RL, Park SK. Estimation of fetal weight with the use of head, body, and femur measurements--a prospective study. Am J Obstet Gynecol. 1985;151(3):333-337. doi:
12. American Institute of Ultrasound in Medicine. AIUM practice parameter for the performance of Fetal echocardiography . 2013:2/14/2018.
13. Forouzan I, Cohen AW, Arger P. Measurement of systolic-diastolic ratio in the umbilical artery by continuous-wave and pulsed-wave doppler ultrasound: Comparison at different sites. Obstet Gynecol. 1991;77(2):209-212.
14. Mari G. Doppler ultrasonography in obstetrics: From the diagnosis of fetal anemia to the treatment of intrauterine growth-restricted fetuses. Am J Obstet Gynecol. 2009;200(6):613.e1-613.e9. doi:
15. Acharya G, Wilsgaard T, Berntsen GK, Maltau JM, Kiserud T. Reference ranges for serial measurements of umbilical artery doppler indices in the second half of pregnancy. Am J Obstet Gynecol. 2005;192(3):937-944. doi: