Association of serum levels of vascular endothelial growth factor and placental growth factor in early threatened abortion and premature delivery: A case-control study

Vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) serve key roles in the regulation of vascular development, revascularization and vasopermeability in the endometrium, decidua and trophoblasts. Furthermore, both VEGF and PlGF are modulators of embryonic vascular development. Thus, the present study aimed to investigate the serum levels of VEGF and PlGF in female patients with early threatened abortion (TA) who experienced preterm delivery. The present case-control study included 130 pregnant patients with or without TA that were admitted to The Maternal and Childcare Hospital of Nantong University from January 2019 to January 2022. Patients were divided into two groups: i) Group A, which included 55 patients diagnosed with TA with slight vaginal bleeding and closed cervical internal os within the first 6-12 weeks of pregnancy; and ii) group B, which included 75 patients with healthy asymptomatic pregnancy. Blood samples were obtained from all patients and VEGF and PlGF levels were examined prior to treatment, and the chi-squared, Student's t-test and two-way ANOVA followed by Bonferroni's post hoc analysis were used to analyze statistical differences between the two patient groups. Results of the present study demonstrated that patients with TA had significantly lower levels of VEGF and PlGF, compared with the controls. In patients with or without TA, the levels of serum PlGF in the preterm delivery group were significantly decreased compared with patients that did not experience preterm delivery. However, there was no significant difference in the levels of VEGF between patients with or without preterm delivery. In addition, lower levels of PlGF, compared with those in patients without TA, may be associated with an increased risk of preterm delivery in patients without early TA.