GNRH1 and fetal growth restriction: In the independently enriched signaling pathways, the high-expressed miRNAs in the normal group were enriched in the GnRH signaling pathway, PI3K-Akt signaling pathway, growth hormone synthesis, secretion and action, insulin secretion, and other pathways closely related to IUGR development [6,10]; however, the highly expressed miRNAs in the IUGR group were mainly enriched in amino acid and fatty acid metabolism pathways.