Normal acetylcholine and receptors. Nicotine affects the neurotransmitter acetylcholine and its receptor. This receptor is located in many brain structures and body organs. It carries messages related to respiration, heart rate, memory, alertness, and muscle movement.
Around the middle of the second trimester, movement of the fetus may be felt. At 28 weeks, more than 90% of babies can survive outside of the uterus if provided high-quality medical care. The third trimester is from 29 weeks through 40 weeks.
1 What is the third trimester (week 29-week 40)? 2  How will my baby develop week by week? 3  What are the changes that happen to a woman's body during the 1st, 2nd, and 3rd trimester of her pregnancy?