Correlation between umbilical cord concentration of the growth hormone-IGF axis and small for gestational age: A single-center retrospective, observational study.

Objective: To ascertain the association between small for gestational age (SGA) and growth hormone (GH)-insulin-like growth factor (IGF) system status.

Methods: This retrospective, observational single-center study at a tertiary hospital classified 175 newborns into two groups based on their gestational age and birth weight: SGA (n = 87) or appropriate for gestational age (AGA; n = 88). Umbilical cord blood samples were collected during delivery, and GH, IGF-1, and IGF-binding protein-3 (IGFBP-3) levels were measured using electrochemiluminescence immunoassay, liquid chromatography-tandem mass spectrometry, and chemiluminescence immunoassay, respectively.

Results: Compared with the AGA group, the GH concentration was significantly higher in the SGA group and the IGF-1 concentration was significantly lower; there was no significant difference in the IGFBP-3 concentration between the two groups. Gestational age, cesarean section, pre-pregnancy maternal body mass index (BMI), weight gain during pregnancy, gestational hypothyroidism, and IGF-1 concentration had a significantly positive association with neonatal birth weight. After adjusting for maternal age, gestational age, fetal sex, mode of delivery, pre-pregnancy BMI, gestational weight gain, gestational hypertension, gestational hypothyroidism, and gestational diabetes, elevated GH levels and decreased IGF-1 levels were both significantly associated with an increased risk of SGA, but there was no association with IGFBP-3.

Conclusions: Levels of IGF-1 and GH in the GH-IGF system are associated with SGA. Elevated GH levels and decreased IGF-1 levels both increase the incidence of SGA. Imbalance in the GH-IGF-1 axis may restrict fetal growth and development, thereby increasing the risk of future metabolic diseases.