What Happens Inside The Fetus

First Two Weeks of Embryo Development: 

• Embryo Is Quite Resistant To Outside Influences

4th Week of Embryo Development:

• Embryo Is Growing Rapidly
• Embryo Is About 5 mm In Length
• Embryo Weighs About 0.02 g  
• All Major Organs Have Begun To Develop In The Embryo

8th Week of Embryo Development:

• Body Shape Of Embryo Is Forming
• All Major Organs Are Being Established
• Embryo Is More Sensitive To Disturbances

Two Months of Embryo Development:

• Embryo Becomes A Fetus

Nine Months of Embryo Development:

• Embryo Goes Through A Growth Phase
• Fetus Grows From 28 mm to 350 mm In Length
• Fetus Grows From 2.7 g to 3000 g In Weight
• Some Organ Systems Continue To Develop