Revista Brasileira de Ginecologia e Obstetrícia (Oct 2004)
Associação entre a antropometria e a leptina circulante nos compartimentos materno, fetal e placentário, na gravidez normal Association between anthropometry and circulating leptin in maternal, fetal and placental compartments, in healthy pregnancy
Abstract
OBJETIVO: avaliar a importância da leptina materna e fetal circulantes na gestação saudável por meio da avaliação de sua associação com variáveis antropométricas materna, placentária e fetal ao nascimento e as relações entre os compartimentos avaliados. MÉTODOS: em estudo transversal foi incluída amostra de 33 gestações únicas, a termo, com fetos saudáveis. As variáveis avaliadas foram idade materna, peso materno, índice de massa corporal, peso do recém-nascido, peso placentário e índice placentário. Amostras de sangue materno foram obtidas imediatamente antes do parto e em sangue do cordão umbilical ao nascimento. A dosagem da leptina sérica foi realizada por meio de radioimunoensaio convencional. As relações entre as concentrações de leptina sérica materna e da artéria e veia umbilicais com as variáveis de estudo foram verificadas através da regressão linear. RESULTADOS: a leptina foi detectada no sangue de todas as 33 gestantes e seus respectivos recém-nascidos, sendo a concentração no sangue materno (17,1±1,77 ng/ml) superior à dos vasos umbilicais (veia 9,0±1,16 ng/mL; artéria 8,2±1,02 ng/mL), pPURPOSE: to evaluate the importance of circulating maternal and fetal leptin in the healthy gestation, using its association with maternal, placental and fetal anthropometric variables, obtained at birth, and the relationship between the evaluated compartments. METHODS: in a transversal study a population of 33 single, healthy and term gestations was studied. The evaluated variables were maternal age, maternal weight, body mass index (BMF), weight of the newborn, placental weight, and placental index. Samples of maternal blood were immediately obtained before birth and from fetal umbilical cord blood at birth. Determination of serum leptin was performed using conventional radioimmunoassay. The relationships between serum leptin concentrations in maternal blood, umbilical artery and vein and the studied variables were assessed through linear regression. RESULTS: leptin levels were detected in the blood of all 33 pregnant women and their respective newborns, with maternal blood concentration (17.1±1.77 ng/mL) higher than that of umbilical vessels (vein: 9.0±1.16 ng/mL; artery: 8.23±1.02 ng/mL), p<0.0001. Leptin concentrations in the maternal blood were correlated with leptin concentrations in fetal blood (artery: coef. 0.63, p=0.037; vein: coef. 0.72, p=0.006). Regarding the anthropometric variables, leptin measured in the maternal blood was associated with initial and final maternal BMF (coef. 1.13; p=0.002; coef. 1,18, p=0.001) and cord leptin levels were correlated with the fetal weight at birth (vein: coef. 0.007, p=0.02; artery: coef. 0.006, p=0.02). CONCLUSION: there was a correlation between maternal and fetal leptin production and probably by the action of similar stimuli during gestation. Serum leptin was associated with the weight of the compartment where it circulates.
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