Objectives: The objective of this investigation is to ascertain whether there is an increase in the levels of heat shock protein 70 (HSP70), a signal for cellular stress, in the maternal bloodstream and umbilical cord of pregnancies affected by gestational diabetes mellitus (GDM). Additionally, the aim is to explore whether variations in the concentrations of Hsp70 in umbilical cord serum can be indicative of the likelihood of early term delivery (between 37 0/7 and 38 6/7 weeks of gestation) in women diagnosed with GDM compared to the control group. Methods: In this case-control study, 62 individuals diagnosed with gestational diabetes mellitus (GDM) comprised the GDM group while 22 non-diabetic, healthy women scheduled for cesarean section formed the control group. Our analysis encompassed the examination of Hsp70 serum levels in both maternal pregnancies and umbilical cord sera, alongside an evaluation of various biochemical and anthropometric markers. Additionally, the study explored the occurrence of early term delivery among all subjects. Results: The concentration of Hsp70 in the maternal serum exhibited a notable increase among individuals diagnosed with gestational diabetes mellitus (GDM) compared to healthy pregnant women. Similarly, the levels of Hsp70 in the umbilical cord were elevated in GDM patients although the difference did not reach the commonly accepted significance threshold. Notably, cord Hsp70 levels displayed a statistically significant negative correlation with the time of delivery in women with GDM. This inverse relationship with the time of delivery was also observed in the overall study group, indicating a potential association between cord Hsp70 levels and the timing of delivery. Conclusion: Maternal Hsp70 was significantly higher in patients with GDM. The obtained results seem to indicate that elevated umbilical cord Hsp70 values may potentially be used as indicators of risk factor for preterm delivery in pregnancies.