Maternal Essential Fatty Acid supplementation diminishes the severity of fetal growth restriction in the rat

Objective The aim of this study was to test the impact of daily oral essential fatty acid (EFA) supplementation on fetal growth and viability during the last week of pregnancy, in rats that had been subjected to bilateral uterine artery ligation on day 14 of pregnancy. Study design Pregnant rats were allocated to one of the following three groups: group S-L, supplementation after ligation; group NS-L, no supplementation after ligation; group NS-NL, no supplementation and not subjected to ligation. All rats had free access to water and food throughout the experimental period. On pregnancy day 14 the rats allocated to the S-L group (n = 7) and the NS-L group (n = 6) were subjected to surgery under general anesthesia. The rats of the NS-NL group (n = 4) had no surgery and served as controls. From pregnancy day 14 onward the rats in the 5-L group received a daily food supplement that consisted of a suspension of EFAs, by oral injection. On pregnancy day 20 the animals were sacrificed. After weighing of all conceptuses and a fetal viability check, the viable fetuses were sacrificed by decapitation. Results Uterine artery ligation was associated with a high rate of fetal loss, as evidenced by a low percentage of viable fetuses in the NS-L group (68%) relative to the NS-NL control group (97%). Supplementation (S-L group) led to a higher percentage of viable fetuses (93% vs. 68%), and also to fewer growth-restricted fetuses: 22% vs. 30% below the reference fetal weight (NS-NL group). Conclusions These results provide some indirect evidence of a favorable role for EFA supplementation on fetal growth in advanced rat pregnancy. This requires further investigation in other species and suggests that maternal supplementation with EFAs could represent a promising nutritional approach in the management of pregnancy with intrauterine growth restriction because of compromised uteroplacental blood flow.