Umbilical vein vasomotion detected in vivo by serial three‐dimensional pixelwise spatially angle‐corrected volume flow measurements

ABSTRACT Objective To explore changes in volume flow in the umbilical vein in healthy second‐trimester fetuses. Methods This was a prospective observational pilot study performed at Stavanger University Hospital, Norway, between May and October 2013. Serial three‐dimensional ultrasound recordings from the umbilical vein were acquired every 30 s in a 5‐min period in 43 fetuses at 17–20 weeks' gestation. The recordings were analyzed with pixelwise spatially angle‐corrected volume flow measurements. Results We observed variation in the umbilical vein volume flow in all fetuses, ranging from a mean minimum of 1.01 mL/s to a mean maximum of 2.60 mL/s. The minimum of all measurements was 57% compared with the mean value and the maximum was 148% of the mean value. The individual flow volume measurements ranged between 0.11 and 4.14 mL/s (mean, 1.76 mL/s). Within this range, an undulating course of all perfusion parameters was observed, with a full period of 4–5 min duration. Conclusion Healthy second‐trimester fetuses show cyclical variation in blood flow in the umbilical vein. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.