Obesity during pregnancy is associated with heightened risks of adverse outcomes for both mother and child. In this regard, perinatal research has seen a growing focus, particularly concerning the autonomic nervous system (ANS). This study aims to explore the autonomic cardiac adaptations in fetuses of obese mothers during labor, contrasting these findings with fetuses from non-obese mothers. We conducted an observational study with a sample of parturient women who attended the Gynecology and Obstetrics Hospital of the Maternal and Child Institute of the State of Mexico. Fetal beat-to-beat RR signals were analyzed using linear and nonlinear techniques, including time and frequency domain analysis and symbolic dynamics. Results indicate significant differences in autonomic cardiac adaptations between fetuses of obese and normal-weight mothers. Specifically, fetuses of obese mothers showed higher RMSSD values, suggesting activation of the parasympathetic pathway. Significant alterations were also observed in frequency indices (LFnu, HFnu) and the sympatho-vagal ratio, V0, and V2 resulting in lower and higher values, respectively, in the obese group displaying a trend towards parasympathetic dominance. These findings suggest that maternal obesity can induce a blunted sympathetic activation associated with an overactivation of the parasympathetic pathway.