Estudo da correlação entre o índice ponderal neonatal e a concentração de leptina no sangue materno e de cordão umbilical

Abstract

OBJECTIVE: verify correlation existence between neonatal ponderal index (IP) and leptin concentration maternal and fetal; verify if there are correlations between leptin concentration maternal and fetal in the presence of fetal macrosomia. SUTDY DESIGN: this is a cross-sectional study carried out from March 2001 to February 2003, in which 61 gestations were evaluated, being 30 healthy patients (group control) and 31 pregnant whose fetuses were considered macrosomic when beingborn, that is, that presented ponderal index (IP) in percentile equal or greater than 90 (group study); Were collected samples of maternal blood and of the umbilical cord blood at delivery, for posterior determination of leptin concentrations in maternal and fetal, arterial and venous, through conventional enzymatic radioimunnoassay (RIA). Was calculated the difference among seric dosages of leptin obtained in the umbilical cord blood ( art-ven). The IP was obtained dividing the weight of the newborn (grams) by the stature (cm) to the cube and multiplied by 100. It used Pearson's Correlation for evaluation the correlation existence between leptin concentration and IP. All the results were considered significant for a probability lower than 5% (p < 0,05), confidence interval at least 95%, for the conclusions. RESULTS: Regarding leptin concentration, the results showed similarities among groups: maternal, arterial fetal, venous fetal and difference arterial and venous (art-ven). Regarding the relation study between IP and leptin, were not identified significant correlations. It verified tendency of positive correlation between IP and leptin concentration arterial fetal in the newborn macrosomics group. CONCLUSION: In the studied group, leptin does not constitute separately a growth ponderal marker fetal.