Effect of maternal cigarette smoking on Apgar scores.

As shown in a total of 43,492 live-born singleton infants, the proportion of low and depressed Apgar scores is related to the extent of maternal cigarette usage during pregnancy. In particular, the three-pack level of smoking (41 to 60 cigarettes per day) is reflected in a near-quadrupling of low and depressed one-minute and five-minute Apgar scores in both blacks and whites and also after exclusion of prematurely born infants.