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.
Keep in mind that you still need prenatal vitamins, at least eight glasses of water a day and 1,000 milligrams of calcium daily. Keep moving. As long as you're not at risk for delivering a preterm baby, exercise is safe in the third trimester.