Critical period.
During pregnancy, every part of the baby's body forms at a certain point. During this time, the body can be very sensitive to damage caused by drugs, alcohol, or other harmful stresses.
All pregnancies have a chance of starting with a birth defect. This is called background risk. If an exposure increases the chance of a birth defect, that chance depends on which part of the body is developing at the time of the exposure.
Once the body parts are formed, the risk of developing serious birth defects disappears. However, some exposures can affect the growth and function of some parts of the body.
Read more about embryonic development at:
brainly.com/question/27407273
#SPJ4
