Figure 1.

Flow diagram of animals use for experimental procedures. After eligibility was determined, pregnant ewes were assigned at random to an experimental treatment, IUGR or control, at 39 ± 1 day of gestation. Sham or bilateral AD surgical procedures were performed at 98 ± 1 day. One control and one IUGR fetus were lost during the first surgery due to complications. Two Intact-IUGR and three AD-IUGR fetuses died between the first and second surgeries. All fetuses survived the second surgical procedure when catheters were inserted. Two AD-control and two AD-IUGR fetuses were excluded from the analysis due to incomplete AD. The final groups are composed of fetuses that completed both ambient and oxygen reversal GSIS studies.