INFLUENCE OF SMOKING, WEIGHT-GAIN, AND PRE-GRAVID WEIGHT FOR HEIGHT ON INTRAUTERINE GROWTH

Combined effects of pregravid weight, weight gain and smoking on birth weight, length and head circumference were investigated in uncomplicated, term pregnancies. Each gravida was categorized by height and pregravid weight as underweight, normal, moderately overweight or massively overweight. Weight gain was grouped as poor, low normal, high normal and excessive. Women who smoked 10-20 cigarettes daily were studied. Women who did not smoke were used as controls. Birth weight, length and head circumference were evaluated. Within each pregravid category and each gain group there was nearly uniform incremental increase in mean birthweight with advancing weight gain in smoking and nonsmoking women. Infants born to smoking women fell behind nonsmoking counterparts by an entire gain group regardless of the mother''s pregravid classification. Similar trends were observed in length and head circumference, although not as pronounced. Encouragement of higher weight gains helps correct the growth retardation in infants born to women who smoke.