How the maternal environment impacts fetal and placental development: implications for livestock production

Fetal survival is dependent upon proper placental growth and vascularity early in pregnancy. The ability for the fetus to reach its genetic growth potential is dependent upon the continual plasticity of placental function throughout gestation. Inadequate maternal environment has been documented to alter fetal organogenesis and growth, thus leading to improper postnatal growth and performance in many livestock species. The timing and duration of maternal nutritional restriction appears to influence the capillary vascularity, angiogenic profile, and vascular function of the placenta in cattle and sheep. In environments where fetal growth and/or fetal organogenesis are compromised, potential therapeutics may augment placental nutrient transport capacity and improve offspring performance. Supplementation of specific nutrients, including protein, as well as hormone supplements, such as indolamines, during times of nutrient restriction may assist placental function. The use of Doppler ultrasonography has allowed for repeated measurements of uterine and umbilical blood flows including assessment of uteroplacental hemodynamics in cattle, sheep, and swine. Moreover, these variables can be monitored in conjugation with placental capacity and fetal growth at specific time points of gestation. Elucidating the consequences of inadequate maternal intake on the continual plasticity of placental function will allow us to determine the proper timing and duration for intervention.