Clinically, Doppler blood flow measurements in growth restricted human fetuses suggest a redistribution of combined ventricular output in favour of ‘vital’ organs, probably due to hypoxia. However, there is no direct evidence to date that similar fetal responses occur in the face of undernutrition. The carotid body is well established as a mediator of fetal cardiovascular responses to hypoxia (Giussani et al 1993). In adults, the carotid body is sensitive to blood glucose (Pardal & Lopez-Barneo 2002) and is involved in glucose homeostasis (Alvarez-Buylla et al 1997). The purpose of this study was to investigate the role the carotid body plays in fetal nutrient detection and growth. Pregnant Merino ewes (Animal Experimentation Ethics Committee, Department of Agriculture, Western Australia) of uniform body weight were housed individually and fed 100% total nutritional requirement, supplemented with 0.5kg barley straw per day, for 2 weeks. At 111 to 115 days gestation (dGA) the ewes were anaesthetised (3% halothane/O2) for fetal surgery. The fetal carotid sinus nerves were sectioned bilaterally (CSD, n= 19) or the nerve was identified but not cut (sham, n= 23). After 5 days of recovery, ewes were fed 100% (CSD, n= 10, sham, n= 12) or 50% (CSD, n= 9, sham, n= 11) total nutritional requirements for three weeks, until post-mortem (140 to 145 dGA). Placental and fetal organ weights and fetal size data were analysed by two-way ANOVA with post-hoc Student’s t-tests, and by linear regression (LR) analysis against ewe weight change over the experimental period. There was an interaction between the effects of CSD and diet on kidney and adrenal weights (p<0.05 ANOVA). In all sham animals, ewe weight change over the experimental period was negatively correlated with fetal adrenal weight (r²=0.19 p<0.05 LR) and positively correlated with fetal liver weight (r²= 0.18 p<0.05 LR), both as percent fetal body weight. This effect was not observed in CSD animals. In sham males, but not sham females, heart weight was positively correlated with ewe weight change (r²= 0.24 p<0.05 LR). This effect was not observed in CSD animals. This study suggests an organ specific redistribution of nutritional resources following a late-gestation maternal nutrient restriction. This is the first study to show that this depends in part on the carotid body.