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.
Your first trimester prenatal schedule may not differ from that of a single pregnancy; however, you may discover that your healthcare provider wants to see you every two to three weeks. Once you enter into your second trimester, you should expect to have two prenatal visits per month. During the third trimester you should anticipate weekly prenatal appointments. Your healthcare provider may change the amount of appointments based on the health of you and your babies.