476 CHILDHOOD RENAL AND RESPIRATORY DISEASE AS A MATERNAL RISK FACTOR IN LOW BIRTH WEIGHT

In a recent study which assessed the effect of “healed” renal disease on pregnancy outcome the incidence of low birth weight infants born to women with previous illness requiring hospitalization as children was unexpectedly higher than that among siblings of the renal disease cohort (p < 0.05). Further analysis of data from birth certificates of 88 live births to the 109 women with previous respiratory disease and 57 infants to the 64 siblings of the renal disease group indicate that these differences persist. 12 (13.6%) low birth weight infants were born to the renal disease mothers and 11 (18.3%) low birth weight infants were delivered to the women in the respiratory disease group. 2 (3.5%) of the infants born to the sibling cohort were low birth weight. Gestational age was calculated against LMP. The curves generated by plotting gestational age vs birth weight of the three cohorts were compared to the birth weight curves of Lubchencko and Babson. When race, socioeconomic status and the effect of maternal cigarette smoking were controlled, the differences also persisted. These data challenge the current concept that low socioeconomic status per se is a risk factor for low birth weight. Women with disease severe enough to be hospitalized as children may represent a risk factor for preterm and small for gestational age infants.