Long-term hypoxia alters endocrine and physiologic responses to umbilical cord occlusion in the ovine fetus.

Objective: This study was designed to determine the effect of umbilical cord occlusion (UCO) on fetal endocrine responses in the long-term hypoxemic (LTH) ovine fetus.

Methods: Pregnant ewes were maintained at high altitude (3820 m) from day 30 of gestation. Normoxic control and LTH fetuses were catheterized, and an inflatable occluder was placed on the umbilical cord at day 132 of gestation.