• Placental endocrine signaling centers on lactogenic hormones and GH-family peptides, with measurement methods (RIA) establishing placental lactogen as a key functional readout and immunologic identification of GH-like placental factors [5], [6], [8], [11], [1], [2].

• Placental steroidogenesis and transfer shape fetal exposure, with estrogen biosynthesis in pregnancy, conversion of plasma cholesterol to placental progesterone, and placental cortisol-to-cortisone transformation [20], [7], [15].

• Hemodynamics: placental and fetal circulation mapped through placental bed vessel responses, in utero fetal circulation, and uneven maternal–fetal blood flow distribution, including hypoxia responses and hypertensive states [9], [18], [19], [4].

• Growth signaling in placenta explored by cellular growth studies and insulin/somatomedin-C receptor characterization, highlighting placental development and growth-factor receptor activity [17], [14].