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.
By about 32 weeks your baby is a smaller version of a full term newborn. Babies at this stage have fingernails, toenails and hair, and they weigh roughly 3.5 pounds.This last stretch of third trimester pregnancy will be used for baby's weight gain and the strengthening of internal systems such as the respiratory tract. baby born at 32 weeks has a very good chance of surviving and continuing on in life without long term health problems.