OBJECTIVETo study the feasibility of umbilical cord brain natriuretic peptide (BNP) level measurement for the evaluation of perinatal cardiac function in fetuses from pregnant women with abnormal blood glucose levels and the influence of abnormal blood glucose on fetal cardiac function.

METHODSTwenty-four mothers with gestational diabetes mellitus (n=18) or gestational impaired glucose tolerance (n=6) (diabetic group) were classified into two subgroups according to blood glucose level before delivery: good (n=17) and poor (n=7) glucose control. They underwent fetal echocardiography in their late pregnant periods and fetal cardiac sizes and function were measured. Twenty-five normal pregnant mothers served as the control group. Umbilical cord blood BNP concentrations were measured at delivery.

RESULTSThe umbilical cord blood BNP concentrations in the diabetic group were significantly higher than in the control group(114.0+/-39.0 pg/mL vs 80.6+/-13.7 pg/mL; p<0.01). The poor glucose control subgroup demonstrated higher umbilical cord blood BNP concentrations than the good glucose control subgroup (142.1+/-44.1 pg/mL vs 102.4+/-31.2 pg/mL; p<0.01). No difference was found between the gestational diabetes mellitus and the impaired glucose tolerance groups. The BNP concentration was positively correlated to the thicknesses of fetal left ventricular walls and the peak velocities of mitral A wave (r=0.715, 0.491 respectively, p<0.05), and negatively correlated to the mitral E/A ratio (r=-0.507, p<0.05).

CONCLUSIONSThe fetuses of pregnant women with abnormal blood glucose levels have an increased BNP level in umbilical cord blood. Umbilical cord BNP level is related to maternal blood glucose control and the changes in fetal cardiac function. It may reflex the latent impairments of fetal cardiac function. A good glucose control may decrease the impact of abnormal maternal blood glucose on fetal hearts.