Those with the most favorable pregnancy outcomes did not smoke, and gained 40 to 45 pounds. The researchers concluded that women carrying twins should gain at least one pound a week, with an overall weight gain of 35 pounds or more. A study of nearly 25,000 pregnancies indicates that many women considered to be past their due date actually were not. The date of the last menstrual period is often used as a basis to calculate due dates, but we are coming to understand that this system often gives incorrect dates. Evaluation by ultrasound revealed that most of the women considered to be post term actually were not.
Tobacco use seems to weaken the bones and slow production of new bone cells.
Smoking also hinders the blood supply to the bones or interferes with the function of osteoblasts. The use of an epidural anesthesia during childbirth may produce a fever in both the mother and child, which may lead to unnecessary suffering, testing and anxiety.