Expression and clinical significance of Klotho protein in serum, umbilical cord blood, and placenta of pregnant women with intrauterine growth restriction

Objectives Intrauterine growth restriction (IUGR) significantly affects neonatal development, but its pathogenesis is not fully understood. Klotho protein is involved in aging-related diseases, and its role in fetal growth is unclear. This study aims to explore Klotho's role in IUGR. Methods A case-control study was conducted at Nanning Maternal and Child Health Care Hospital from July 2023 to June 2024. Fifty-two neonates (gestational age ≥34 weeks and <42 weeks) were divided into the appropriate for gestational age (AGA) group ( n = 30) and the IUGR group ( n = 22). Venous and umbilical cord blood were collected to measure Klotho, growth hormone (GH), and insulin-like growth factor 1 (IGF-1). Placental tissues were examined for histopathology and immunohistochemistry. Results The IUGR group showed placental morphological changes, including increased syncytial knots and inflammation. Klotho expression in placental tissue was significantly reduced ( p < 0.0001), while IGF-1 levels increased ( p < 0.001) and GH levels decreased ( p < 0.001). Soluble α-Klotho levels were lower in maternal venous blood ( p < 0.0001) and umbilical cord blood ( p < 0.01). GH and IGF-1 levels in maternal venous blood and umbilical cord blood were altered in IUGR cases. Conclusions Reduced Klotho expression in IUGR cases, along with changes in GH and IGF-1, suggests disruptions in metabolic processes affecting fetal growth and development. These findings suggest a potential involvement of Klotho in placental changes and fetal development, warranting further mechanistic studies.