Modification of sexual dimorphism of weight in intrauterine growth retardation

Abstract

Sexual dimorphism(SD) include morphological and physiological differences between sexes. It reflects the interplay of genetic makeup and the capacities of human beings to react to a different enviroment. Under unfavorable factors, it becomes to be underlayed.

Objective: to identify if there exists an inhibition of SD under intrauterine growth retardation (IUGR) condition.

Patients and Methods: 2 552 newborns with (250) and without (2 302) IUGR were studied. All of them were > 36 weeks of gestation. The population was divided in two groups according intrauterine growth condition and the presence of several maternal adverse factors (pre pregnancy, during pregnancy and enviromental).

Results: There were no statistically significant differences among sex for birth weight between IUGR newborns, and females were heavier than males. On the other hand, newborns with normal intrauterine growth showed statistically significant difference between sex, males were heavier than females. None of the maternal factors modified that condition. We concluded that inhibition of SD is present in fetus under a stress condition.