Hernandez-Valencia M, Zarate A, Ochoa R, Fonseca M E, Amato D, De Jesus Ortiz M
Endocrine Research Unit, Specialties Hospital, National Medical Center, Mexico City, Mexico.
Diabetes Obes Metab. 2001 Dec;3(6):457-62. doi: 10.1046/j.1463-1326.2001.00168.x.
Fetal intrauterine growth retardation (IUGR) is one of the most common obstetric problems, with a frequency of 12% in Mexico. In the past, investigations have focused on extrinsic causes of IUGR. More recent studies have examined the intrinsic factors that cause fetal intrauterine growth. Maintenance of fetal growth has been attributed to insulin-like growth factor (IGF), epidermal growth factor (EGF) and transforming growth factor beta (TGF-beta). The objective of this study was to assess the levels of these growth factors during pregnancy and to determine whether or not low concentrations are associated with IUGR.
Nine women whose pregnancies were complicated by IUGR and a group of nine women whose pregnancies exhibited normal fetal intrauterine growth were studied. IUGR was determined by sonography and confirmed by weight at birth. Venous blood samples were taken from both groups of pregnant women at the end of each trimester. Enzyme-linked immunosorbent assays, immunoradiometric assays and radioimmunoassays were used to process samples, and the results were analysed by anova.
IGF-I levels increased in both groups during pregnancy, but the increase was lower (p < 0.001) in the IUGR group throughout pregnancy and at delivery. EGF did not show any significant changes during pregnancy. Blood TGF-beta levels varied only during the first trimester of pregnancy. The differences were not statistically significant. However, TGF-beta concentrations were higher in the pregnancies with IUGR. Women in the IUGR group were smaller than in the control group (p < 0.05), and, using the covariance test (p < 0.05), this was found to be correlated with IGF-I levels but not with EGF or TGF-beta levels.
Changes in fetal weight might be explained by the different concentrations of IGF. The structural homology between IGF-1 and insulin could mean that the presence of higher levels of IGF would result in a increased energetic metabolism that could contribute to fetal growth. EGF levels were not related to IUGR, and TGF-beta levels increased only during the first 3 months in the IUGR group. This observation correlates with the in vitro action of TGF-beta as a negative factor of growth, but as a positive support for sustaining early pregnancy. Our data illustrates that low height represents an increased risk factor for IUGR. These data also correlate with the studies involving extrinsic factors.
胎儿宫内生长受限（IUGR）是最常见的产科问题之一，在墨西哥发生率为12%。过去，研究主要集中在IUGR的外在原因。最近的研究则探讨了导致胎儿宫内生长的内在因素。胎儿生长的维持归因于胰岛素样生长因子（IGF）、表皮生长因子（EGF）和转化生长因子β（TGF-β）。本研究的目的是评估孕期这些生长因子的水平，并确定低浓度是否与IUGR相关。
研究了9例合并IUGR的孕妇和9例胎儿宫内生长正常的孕妇。IUGR通过超声检查确定，并经出生体重证实。两组孕妇在妊娠各期末采集静脉血样本。采用酶联免疫吸附测定、免疫放射测定和放射免疫测定法处理样本，结果用方差分析进行分析。
两组孕妇孕期IGF-I水平均升高，但IUGR组在整个孕期及分娩时升高幅度较小（p<0.001）。EGF在孕期未显示出任何显著变化。血TGF-β水平仅在妊娠早期有所变化。差异无统计学意义。然而，IUGR孕妇的TGF-β浓度较高。IUGR组孕妇比对照组小（p<0.05），通过协方差检验（p<0.05）发现，这与IGF-I水平相关，但与EGF或TGF-β水平无关。
胎儿体重的变化可能由IGF浓度的差异来解释。IGF-1与胰岛素之间的结构同源性可能意味着较高水平的IGF会导致能量代谢增加，从而有助于胎儿生长。EGF水平与IUGR无关，TGF-β水平仅在IUGR组妊娠前3个月升高。这一观察结果与TGF-β在体外作为生长负因子但作为维持早期妊娠的正性支持因子的作用相关。我们的数据表明，身材矮小是IUGR的一个增加的危险因素。这些数据也与涉及外在因素的研究相关。
