Human Fetus at 40 Weeks in the Womb (Brown Skin)

Description

At 40 weeks of gestation the fetus fills almost the entire uterine cavity, shown here lying on its side within a translucent amniotic sac suspended in amniotic fluid. The head is large and rounded, covered with dark scalp hair, with closed eyelids, a formed external ear and rounded facial contours produced by well developed subcutaneous fat. The limbs are held in the characteristic flexed attitude: hips and knees drawn toward the trunk, the arms folded across the chest with fingers extended, and the feet crossed near the midline. The umbilical cord loops between the lower limbs and passes toward the placental surface visible along the thickened uterine wall on the right of the frame. Term anatomy of this kind underpins obstetric assessment in the final weeks of pregnancy, when clinicians evaluate fetal lie, presentation and engagement before labour. The flexed posture illustrated here corresponds to the attitude of general flexion that presents the smallest cranial diameters to the maternal pelvis, and it is the reference point for describing malpresentation, breech position or deflexed heads. Cord position relative to the limbs and neck is likewise a routine sonographic observation, while placental location and amniotic fluid volume shown around the fetus relate directly to biophysical profile scoring and decisions about timing of delivery. The rendering suits obstetric and midwifery teaching on term fetal development, antenatal class handouts and patient-facing material explaining what the baby looks like at the end of pregnancy. It also serves textbook and atlas figures on intrauterine anatomy, ultrasound training resources that pair schematic anatomy with scan images, and editorial or app content produced for expectant parents. As part of a week-by-week gestational series it provides the final stage against which earlier weeks can be compared. Anatomical accuracy verified by SciePro's Medical Advisory Board.