Fetal Development

• Embryonic Stage


  Week 1 to 12
• Week 8 


  Every organ system present
• Week 12


  Kidneys begin to form urine
• Week 12


  heart tones detected by electronic devices between 8 to 12 weeks
• Fetal Period


  Week 16 to 40
• Week 16


  Lanugo hair begins to develop
• Week 16


  Sex can be determined
• Week 20


  Heart beat detected by fetoscope
• Week 24


  Has ability to hear
• Week of gestation does the fetal heart begin to beat

  Week 4
• Week 24


  Age of Viability
• Week 28 


  Lungs sufficiently developed
• Week 28


  If born, neonate can breathe at this time.
• Week 36 


  Lanugo disappearing