Fetus at Week 18

Description

Fetus at 18 weeks’ gestation appears in a flexed second-trimester posture with the placenta positioned adjacent to the fetal abdomen and the umbilical cord coursing from the umbilicus to its placental insertion. Limb buds have matured into proportioned upper and lower extremities, with distinct hands, feet, and separated digits oriented relative to the trunk in this single fixed pose. Craniofacial contours, external ears, and a prominent head relative to the torso remain evident, while the cord forms a gently curved conduit between fetal and placental surfaces. Placental tissue is shown as a discrete disc, with the cord inserting centrally or eccentrically depending on the modeled anatomy. Obstetric teaching often hinges on what changes around 18 weeks, including rapid skeletal ossification, evolving body proportions, and the point at which many anatomic surveys are scheduled for targeted ultrasound. Cord anatomy matters here: a normally developed cord contains two umbilical arteries and one umbilical vein embedded in Wharton’s jelly, and deviations in insertion (marginal or velamentous) or vessel number (single umbilical artery) carry screening and follow-up implications. The isolated white background keeps attention on fetal-placental relationships and supports clean overlays for labels of placental surface anatomy and the umbilical ring. A good reference point. Use this illustration in embryology and human development modules covering the second trimester, and in obstetrics and prenatal care materials that explain the 18 to 20 week anatomy scan and placental assessment. It also fits patient-facing prenatal counseling graphics when paired with callouts for placenta, umbilical cord, and fetal growth milestones. Anatomical accuracy verified by SciePro's Medical Advisory Board.