Fetal Development at Gestational Week 40

Description

Full-term conceptus is rendered in a flexed, fetal position within the amniotic sac at gestational week 40, with the head curled toward the trunk and the upper and lower limbs tucked in close to the thoracoabdominal wall. A discoid placenta lies adjacent to the sac, connected to the fetal umbilicus by a helically twisted umbilical cord that courses from the placental plate toward the anterior abdominal wall. Membranes of the amnion form the immediate fluid-filled enclosure, while the placenta sits external to the fetus and communicates through the cord. Normal late-gestation spatial packing. Term anatomy matters because this is the baseline against which growth restriction, macrosomia, and abnormal lie are judged in obstetrics, and it frames why the cephalic pole is preferentially engaged for birth when flexion is maintained. The placenta and cord shown together anchor discussions of fetoplacental circulation, including single umbilical vein and paired umbilical arteries, and the clinical consequences when flow is compromised, such as cord compression with variable decelerations or placental insufficiency prompting induction. Cord insertion and membrane relationships also orient the viewer to complications like velamentous insertion or vasa previa, where unprotected fetal vessels traverse the membranes near the internal cervical os. Use this artwork in embryology and obstetrics teaching to contrast embryonic, fetal, and term morphology, and in patient-facing or professional publications explaining placental function, umbilical cord physiology, and the mechanics of fetal flexion before labor. It also suits perinatal pathology references discussing placental examination and cord abnormalities at delivery. Anatomical accuracy verified by SciePro's Medical Advisory Board.