Weeks 15-18 – Baby will suck its thumb and kick and now has fine hair. The intestinal tract is functioning.
Weeks 19-21 – Baby can hear you singing and talking and can feel pain. Fingernails are almost fully grown. You can feel your baby move.
Weeks 22-25 – Baby has eyelashes and fingernails and is very active. The bone marrow is making blood cells, and the lungs are developing but do not make surfactant which is necessary for the baby to breathe outside of the womb.
Weeks 26-28 – Baby's hearing and sight are completely developed now. Your baby can now create tears. If born at this time, your baby would have an 85% survival rate.