Human Fetus at 20 Weeks in the Womb (Brown Skin)

Description

The fetus lies in a flexed attitude inside the translucent amniotic sac, suspended in amniotic fluid and enclosed by the vascularised uterine wall and endometrium. The head is turned toward the viewer with a formed auricle, closed eyelids and a rounded cranium still large in proportion to the trunk; the upper limbs are drawn up in front of the chest with separated fingers, and the lower limbs are crossed at the ankles with fully modelled feet and toes. The discoid placenta is attached to the uterine wall posterosuperior to the fetus, its chorionic plate marked by branching fetal vessels, and the umbilical cord leaves the placental insertion in a helical spiral of two umbilical arteries and one umbilical vein to reach the fetal abdomen. Skin remains thin and translucent, so subcutaneous vessels and the underlying contours of the ribs and shoulder girdle are faintly visible. At around 20 weeks the pregnancy is at the midpoint of gestation and at the time of the standard second-trimester anomaly scan, when biometry such as biparietal diameter, head and abdominal circumference and femur length is measured against reference charts. This is also when placental site, cord insertion, amniotic fluid volume and vessel number are documented, and when limb, cardiac and neural tube anatomy can be surveyed in detail. Depictions of fetal posture and cord coiling at this stage support explanations of first perceived fetal movements, of umbilical cord anatomy relevant to Doppler assessment, and of the maternal-fetal interface in discussions of growth restriction or placental insufficiency. The rendering suits obstetric and midwifery teaching, embryology and developmental anatomy atlases, antenatal class and clinic handouts, and week-by-week pregnancy resources for patients. It also serves publishers, health-app developers and ultrasound training material needing a consistent visual reference across successive gestational weeks. Anatomical accuracy verified by SciePro's Medical Advisory Board.