Human Fetus at 22 Weeks in the Womb (Brown Skin)

Description

A fetus of approximately 22 weeks' gestation lies in a flexed attitude within the intact amniotic sac, suspended in amniotic fluid and enclosed by the uterine wall. The head is disproportionately large relative to the trunk, with the external ear already well modelled, closed eyelids, a broad nasal bridge and a slightly open mouth toward which one fetal hand is drawn. Thighs are flexed onto the abdomen with the legs crossed, and the plantar surfaces of both feet are turned toward the viewer. The umbilical cord, showing the spiral of paired umbilical arteries and the single umbilical vein, loops across the fetal forehead and occiput and runs off toward the placental disc visible superiorly against the myometrium. At this point in the second trimester the fetus is at the threshold of viability, a stage central to counselling in threatened preterm labour and to decisions about antenatal corticosteroids and neonatal resuscitation. The depicted anatomy also matches what is assessed at the mid-trimester anomaly and growth scan: biometry of the head, limb posture, cord vessel number, placental position and amniotic fluid volume. The nuchal cord loop shown here is a common, usually incidental sonographic finding, while thin, translucent skin and immature subcutaneous fat explain the deep coloration of the fetus and the vulnerability of infants born at this age. Suited to obstetric and midwifery teaching sequences on second-trimester development, embryology and human development atlases, and antenatal class or waiting-room material that helps parents visualise fetal size, posture and movement at 22 weeks. It also serves journal and textbook figures on placental and umbilical cord anatomy, and continuity of care resources produced by neonatology and fetal medicine units. Anatomical accuracy verified by SciePro's Medical Advisory Board.