Transforming growth factor-beta1 in fetal serum correlates with insulin-like growth factor-I and fetal growth

OBJECTIVE: To estimate whether transforming growth factor-beta1 in fetal serum obtained by umbilical cord sampling at delivery is correlated with fetal growth. We also estimated whether transforming growth factor-beta1 is correlated with insulin-like growth factor-I and insulin-like growth factor binding protein-1, which have been shown to correlate with fetal growth. METHODS: The active form of transforming growth factor-beta1 was analyzed in serum from cord blood from 68 fetuses by the enzyme-linked immunosorbent assay technique. Of the 68 pregnant women, 12 had preeclampsia, 14 had preeclampsia and intrauterine growth restriction, 15 had intrauterine growth restriction alone, and seven had fetuses that were large for gestational age (LGA). Twenty pregnancies with fetuses appropriate for gestational age (AGA) served as controls. RESULTS: Transforming growth factor-beta1 concentrations were significantly correlated with birth weight. The average transforming growth factor-beta1 concentration in the following groups were: intrauterine growth restriction, 22.4 +/- 2.7 microg/L; intrauterine growth restriction plus preeclampsia, 22.9 +/- 2.0 microg/L; preeclampsia without intrauterine growth restriction, 28.8 +/- 2.1 microg/L; LGA, 30.3 +/- 4.3 microg/L; and AGA, 36.8 +/- 2.0 microg/L. Transforming growth factor-beta1 levels were significantly lower in pregnancies complicated by intrauterine growth restriction and showed a positive correlation with birth weight (r = 0.48, P <.001). Furthermore, there was a positive correlation between insulin-like growth factor-I levels and birth weight (r = 0.36, P <.01) and a negative correlation between insulin-like growth factor binding protein-1 and birth weight (r = -0.32, P <.01). There was also a correlation between transforming growth factor-beta1 and insulin-like growth factor-I (r = 0.29, P <.05) and between transforming growth factor-beta1 and insulin-like growth factor binding protein-1 (r = -0.25, P <.05). CONCLUSION: Transforming growth factor-beta1 might be related to fetal growth in pregnancy. The results also support previous data showing that insulin-like growth factor-I and insulin-like growth factor binding protein-1 are related to fetal growth.