Fetal magnetic resonance imaging (MRI) is a valuable tool for studying brain development, offering high-resolution characterization of soft tissue morphology. While mainly used for clinical diagnosis, recent studies have applied it to analyze normative brain growth. We present preliminary findings from an ongoing project aimed at describing prenatal brain development in low-risk pregnancies with no suspected pathology, within a socially vulnerable population from the southern Metropolitan Area of Buenos Aires (AMBA), Argentina. The sample included 24 pregnant women with a mean gestational age of 31.33 ± 2.02 weeks. Using features of cortical maturation, cortical age was estimated for each fetus, with a mean of 28.69 ± 3.17 weeks. The correlation between gestational and cortical ages was moderate but highly significant (r = 0.55, p < 0.01). Standard biometric measures —fronto-occipital length, biparietal diameter, and head circumference— were also taken, showing stronger associations with gestational than cortical age. This work presents an initial insight into a distinctive sample, shaped by the specific population studied and the imaging technique employed. Further studies will seek to enlarge the sample and examine how fetal traits relate to maternal characteristics such as nutrition, health status, and broader sociodemographic factors, as well as to explore potential mismatches between growth and the expected maturation for gestational age.