A check valve assembly having a reduced net impact upon hemolysis, where the valve assembly has an elongated valve body including an inlet port, an outlet port, and an internal channel communicating between the ports, with each port disposed about and generally aligned with a central longitudinal axis of the body. The inlet port includes an umbrella-type check valve, and the internal channel is defined by three annular wall portions: a first annular wall portion aligned generally perpendicularly to the longitudinal axis to form a valve seat, a second annular wall potion that is generally concave, and a third annular wall portion that is generally convex, with the first, second and third annular wall portions forming an adjoining and essentially continuously curved, contiguous interior surface which smoothly redirects fluid flow toward the central longitudinal axis of the body and the outlet port.