Figure 1. Late gestation maternal insulin infusion protocol.

Baseline (= 60 min, filled boxes) and maternal insulin infusion (130 min, diagonal striped boxes) periods comprised on-line fetal cardiovascular/ECoG recording, and two periods during which microspheres (MS) were administered to the fetus during episodes of high voltage ECoG activity. Maternal (5.5 ml for hormone and blood gas analysis) and fetal (0.25 ml for blood gas analysis) blood samples were taken at predetermined intervals (arrows). Fetal MS reference blood sample (7.5 ml) plasma was kept for hormone analysis. In study 2 only, an additional 4 ml fetal blood was taken immediately before the MS reference sample for additional hormone analysis.