Relation of maternal cardiac volume to infant maturity

Three hundred forty-seven pregnant women were studied at 20 weeks gestation to determine the relationship between radiographically determined maternal cardiac volume and infant maturity determined by several criteria. Cardiac measurements were made in the prone and erect positions and statistical analyses were used to evaluate the relationships to infant maturity. When maternal measurements were corrected for all linear relationships to mother’s body surface area and to gestation period, no significant relationships between maternal heart and infant maturity variables remained. There was a consistent increase in the probability of prematurity as maternal heart volume (prone) corrected for surface area increased but the small difference is of no practical significance. No significant differences in prematurity rate for different maternal heart volumes determined in the erect position were found. Measurements of maternal cardiac size at 20 weeks gestation are thought to have no practical value in the selection of a “high risk” group of patients for special treatment to avoid prematurity.