Correlations and cumulative frequency distributions of maternal and newborn hematologic data

Nonparametric correlation coefficients and cumulative frequency distributions of hematologic data and birth weight obtained from 151 mothers and most of their newborns have been analyzed. Taken overall, the data reaffirm considerable fetal autonomy in maintaining hematologic homeostasis; a dissociation was found between maternal and newborn hemoglobin (Hb) levels, there was no evidence for an effect of maternal iron deficiency on the fetus, nor was birth weight correlated with maternal Hb levels. However, the lack of significance of the latter two correlations was apparent only when three maternal-newborn pairs with alpha-thalassemia were excluded from analysis. An inverse relation was found between birth weight and Hb level in the newborn, and this was present over the entire birth weight range, rather than being restricted to small-for-gestational-age newborns.