Studies on Relationship of Carbon Monoxide Concentration in Air to Health of Mother and Baby

Abstract

Our previous report described a study of the actual condition of carbon monoxide level in expired air of pregnant women and its relations with life-environmental and physical factors. The present communication deals with an ensuing investigation aimed at clarification of the interrelationship between the relatively low CO concentration in life-environment and the gestation, parturition and neonatal growth, in a series of women and their offspring. The study involved 165 women who were examined during 1 to 2 and 3 to 4 months post parturition at the Metropolitan Koishikawa, Mitaka and Hino Health Centers in Tokyo over the period from January to September 1972, with the results summarized as follows: 1) The incidence of substandard birth weight, i. e. less than M-1/2 ó determined according to weeks of gestation, was found to differ significantly among the three regions. Namely, substandard birth weights were highest in incidence in the group within the jurisdiction of Koishikawa Health Center showing the highest average CO concentration in expired air of the pregnant, followed, in order, by the group within the jurisdiction of Mitaka Health Center and that within the Hino Health Center area. Children with substandard birth weights were more frequent from mothers with higher CO levels in expired air, as compared to children with standard or greater birth weights. 2) Physical examinations conducted on babies 3 to 4 months after birth disclosed a tendency for the child's body weight to be lower in inverse correlation to the mother's CO level in expired air. The examination also revealed a higher incidence of babies with abnormalities in the Koishikawa Health Center area with the highest environmental CO concentration, compared with the two other jurisdictions. 3) Mothers with greater CO concentrations in expired air tended to show higher hemoglobin levels at 3 to 4 months post parturition.