Small-for-gestational-age fetuses: a heterogeneous group requiring reassessment of clinical outcomes

Objective. To investigate the association between antenatal small-for-gestational-age (SGA) status and adverse perinatal outcomes in term neonates.

Materials and methods. This retrospective cohort study included 200 pregnant women who delivered at the V.I. Kulakov National Medical Research Center for Obstetrics, Gynecology, and Perinatology (2020–2025). The study group (n=100) comprised women with singleton term pregnancies complicated by an SGA fetus, while the comparison group (n=100) included women with normally grown fetuses. Clinical and anamnestic characteristics, pregnancy and delivery outcomes, and early neonatal complications were also evaluated. Statistical analyses were performed using JASP software (Student's t-test, Mann–Whitney U test, chi-square test, Fisher's exact test, univariable and multivariable logistic regression; p< 0.05).

Results. SGA status was significantly associated with an increased risk of adverse perinatal outcomes. The incidence of the composite adverse outcome was significantly higher in the SGA group (24%) than in the control group (8%) (p=0.002). Neonates with SGA demonstrated a marked trend toward higher rates of cephalohematoma formation, central nervous system (CNS) disorders, and infectious-inflammatory conditions. In the univariable logistic regression analysis, SGA increased the risk of adverse outcomes by 3.6-fold (odds ratio [OR]=3.63; 95% confidence interval [CI]: 1.54–8.55; p=0.003). Multivariable analysis adjusted for maternal age confirmed that SGA remained an independent predictor of adverse outcomes (adjusted OR=3.62; 95% CI: 1.52–8.62; p=0.004).

Conclusion. SGA is an independent risk factor for adverse perinatal outcomes and warrants reconsideration of traditional views regarding its clinical significance due to the heterogeneity of the population and challenges associated with its diagnosis.