Maternal plasma cytokines concentrations and insulin resistance in first trimester in relation to fetal growth

Fetal growth is determined by genetic factors and placental supply. There is evidence that insulin might contribute to the up-regulation of placental transporter activity. The dysregulation of adiponectin and leptin is found in insulin resistance. The objective of this study was to evaluate the relation of maternal plasma cytokine and insulin concentrations in the first trimester of pregnancy to fetal growth.

55 women with singleton pregnancy, between 12th and 14th weeks of gestation, were included to the study. Plasma concentrations of adiponectin, leptin, insulin and glucose were analyzed together with fetal ultrasound measurements and neonatal birth weight. The HOMA-IR were calculated (fasting insulin (microU/ml) x fasting glucose (mmol/l/22.5) to assess the insulin sensitivity.

Mean concentrations of adiponectin, leptin and insulin were 15.29 +/- 13.83 microg/ml, 6.93+/-5.39 ng/ml and 43.59+/-26.28, respectively. The average insulin resistance defined by HOMA-IR was 1.35+/-0.8. The ratios of adiponectin to leptin, adiponectin to insulin and HOMA-IR were calculated. The percentiles of fetal crown-rump length (CRL) were negatively correlated with adiponectin plasma concentration (r=-0.32; p<0.05), with no relation to leptin and insulin plasma concentration. Correlations between fetus CRL percentile and the ratio of adiponectin to leptin concentration (r=-0.37; p<0.02) and adiponectin to HOMA-IR (r=0.35; p<0.05) were also observed. No association between adiponectin, leptin, fasting insulin, HOMA-IR and neonatal birth weight or birth weight percentile was found. The percentile of fetal CRL in the 1st trimester was positively correlated with neonatal birth weight percentile (r=0.3; p<0.05).

The results of this study imply that maternal adiponectin concentration may play a role in early determination of fetal growth.