Perinatal consequences of maternal-fetal Rh blood group interaction in diabetic pregnancy: a nonimmunological perspective.
BACKGROUND
The recent discoveries about the structure of Rh protein that suggest a transport function and the recent observations of a positive correlation between Rh(D) protein and glycosylated hemoglobin levels in non-insulin-dependent diabetes mellitus prompted us to review our data on diabetic pregnancy to evaluate the perinatal consequences of maternal-fetal Rh blood group interactions in a metabolic perspective.


METHODS
One hundred thirty-two women with gestational diabetes and 120 women with preexisting insulin-dependent diabetes mellitus were examined. Three hundred eighty-seven consecutive nondiabetic puerperae from the same population were considered control subjects.


RESULTS
In both gestational and insulin-dependent diabetes mellitus, an increased proportion of mother Rh(+)/newborn Rh(-) and a decreased proportion of mother Rh(-)/newborn Rh(+) joint phenotype has been observed. No deviation has been observed for joint phenotypes in which mother and newborn are similar [ie, Rh(+)/Rh(+) and Rh(-)/Rh(-)]. In the situation of mother Rh(+)/newborn Rh(-), there is a relatively lower rate of fetal loss and a decreased tendency to high birth weight. On the contrary, in pairs mother Rh(-)/newborn Rh(+) the fetus shows an increase of fetal loss and of tendency to high birth weight.


CONCLUSIONS
The results are compatible with the hypothesis that when the density of Rh protein in the mother is higher than that in the fetus, the conceptus is relatively protected against the toxic effect of glucose. In the opposite genotypic combination (ie, density of Rh protein higher in the fetus than in the mother), the fetus is relatively more susceptible to these effects.
Department of Preventive and Social Pediatrics, University of Rome Tor Vergata, School of Medicine, Italy. bottini64@med.uniroma2.it
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Gloria-Bottini
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Bottini
D001724:Birth Weight; D003922:Diabetes Mellitus, Type 1 / Q000276:immunology*; D005260:Female; D006031:Glycosylation; D006801:Humans; D007231:Infant, Newborn; D011247:Pregnancy; D011254:Pregnancy in Diabetics / Q000276:immunology*; D012204:Rh-Hr Blood-Group System
D012204:Rh-Hr Blood-Group System