The neck is developing and the chin lifts up from the chest. Fingernails are also present. While your baby's sex was already determined at the time of fertilization, male or female genitalia are now visible. Essential organs are formed and most have begun to function. The blood vessels in the placenta are increasing in number to meet your baby's increasing nutritional needs. Her ears are moving towards the sides of her head, away from the neck. Your baby's head is still not in proportion with her body. Your baby's head accounts for about half of her body length.