The human foetus after 5-6 months, showing a close-up of the hands & mouth. The upper limbs deveop at a faster rate than do the lower ones; a feature that continues even after birth. The foetus moves actively at this time & sucks its thumb. It also sucks in quantities of the surrounding amniotic fluid, which the kidneys slowly process & return to the amniotic fluid. No waste is discharged via the rectum - the mother's circulation is active in waste disposal at this time.