Week 17: The baby can have dream (REM) sleep. The baby is now the size of a pear.
Week 18: The baby is the size of a sweet potato.
Week 19: Babies can routinely be saved at 21 to 22 weeks after fertilization and sometimes they can be saved even younger. The baby is the size of a mango.
Week 20: The earliest stage at which partial birth abortions are performed. At 20 weeks the baby recognizes its mother’s voice. The baby is around the same size as a artichoke.