Three month old foetus. Side view of a three month old human foetus removed from its umbilical cord and amniotic sac. By this stage in its development the foetus crown-rump length (sitting height) is about 30mm. The head (at left) has a visible nose, mouth and chin. The head is proportionately large although the body is elongating at this stage. Fingers and toes are formed. Most of the organs have developed, but require growth. The genitals have formed and the sex is determined (male in this case).