Unfortunately, previous studies have been limited by relatively small numbers. Few studies have controlled for factors known to affect infant birth weight, such as maternal race, height, weight, parity, nutrition, and cigarette smoking. Particularly, race may be an important contributing factor in assessing the relationship between asthma and pregnancy outcomes, since Blacks of both sexes are twice as likely to be hospitalized from asthma and three times as likely to die from asthma as whites.