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

Description

The fetus is shown in the characteristic flexed attitude of the mid second trimester, with the vertebral column curved into a C-shape, the head inclined toward the chest and the limbs drawn in against the trunk. One hand rests near the face while the feet are brought up in front of the abdomen, and the external ear is now fully modelled on the side of the head. The umbilical cord arises from the abdominal wall and spirals across the field, its two umbilical arteries and single umbilical vein indicated by the twisted colour pattern, inserting into the placental disc that lies against the richly vascular uterine wall behind. Surrounding amniotic fluid and the translucent decidual surface give the sense of enclosed space within the gravid uterus. Twenty weeks marks the midpoint of gestation and the usual timing of the detailed anatomy ultrasound, when biometry such as biparietal diameter, head and abdominal circumference and femur length are measured against reference charts. The relationships visible here — cord insertion site, number of cord vessels, and placental position relative to the uterine wall — are exactly the features assessed sonographically when screening for single umbilical artery, velamentous insertion, praevia or growth restriction. Fetal posture and limb position are also relevant to early assessment of movement and joint development. The image suits obstetric and midwifery teaching on second trimester development, antenatal clinic and childbirth education material, and pregnancy apps or websites that follow gestation week by week. It also serves embryology and human development textbooks, ultrasound training resources needing an anatomical companion to scan images, and publication figures on placental and umbilical cord anatomy. As part of a weekly series it allows direct visual comparison of fetal size and proportion across successive weeks. Anatomical accuracy verified by SciePro's Medical Advisory Board.