At 39 weeks, babies weigh about 3kg to 3.2kg and are still storing fat that helps regulate their body temperature after birth....His internal organs are fully functional, but his lungs are the last to complete....Even after birth, it may take a few hours for him to find a normal breathing pattern....His eye color may gradually change after contact with his ex's eyes..He can now make tight fists. Make... Eyes: If your baby is born with brown eyes, they will usually stay brown... and if they are born with blue or dark gray eyes, they may change to brown, green or hazel in the first year of life....