Objective: To evaluate the flow of the superior mesenteric artery and vein both by Doppler flowmetry and simultaneously, in normal controls and in cases of gastroschisis, as additional prognostic criteria. Methods: The venous/arterial index was determined by Doppler flowmetry; reference values for the superior mesenteric vessels were obtained from a group of 60 healthy fetuses of 30 to 34 weeks and 15 cases of gastroschisis. The flow rate wave (FRW) was obtained simultaneously from both the superior mesenteric artery and vein with an angle of insonation less than 60°; the vein velocity was divided by the systolic peak of the artery and the percentage index was calculated based on the velocity of both vessels. The equipment used was a Mylab™Twice from Esaote with a 3.5 MHz convex probe. Results: The superior mesenteric venous/arterial index value in the control group was 26% ± 6 (2SD)...