Placental gene expression of transforming growth factor beta 1 (TGF-β1) in small for gestational age newborns.

Objective: The gene expression of transforming growth factor beta-1 (TGF-beta 1) in human placental samples obtained from pregnancies with small for gestational age fetuses (SGA) was compared to those of normal pregnancies. Methods: In 2011 placental samples from 101 pregnancies with SGA and from 140 normal pregnancies were obtained for analysis of TGF-beta 1 gene expression. Several clinical parameters were also assessed for correlation between genetic and clinical parameters. Results: There were no significant differences in gene activity of the TGF-beta 1 gene between the SGA versus normal pregnancy groups (Ln2(alpha): 0.16; p = 0.07). Within the SGA group, no fetal gender-dependent differences were seen in TGF-beta 1 gene expression (Ln2(alpha): -0.11; p = 0.05). Similarly, no significant differences in gene activity were observed by the degree of severity of SGA as assessed by percentile fetal birth-weight (Ln2(alpha): 0.32; p = 0.06). Conclusion: We found no change in gene expression of TGF-beta 1 in placental samples obtained from SGA pregnancies versus normal pregnancy suggesting an absence of a direct role of the TGF-beta 1 gene in the development of SGA. However, the absence of increased gene expression of TGF-beta 1 in SGA can be conceptualized as a failure to mount a compensatory response in the SGA environment.