Background: Gestational diabetes mellitus (GDM) is associated with metabolic disturbances extending beyond glucose homeostasis, including alterations in lipid metabolism. However, evidence on the fatty acid composition of maternal serum lipids in GDM remains inconsistent, and data on placental fatty acid transfer are limited. This study aimed to explore associations between maternal serum lipid fatty acid composition, selected FA indices, and transplacental transfer of fatty acids derived from maternal serum lipids in pregnancies complicated by GDM. Methods: A cross-sectional study was conducted among 139 pregnant women, including 104 healthy controls and 35 women with GDM. Maternal serum and umbilical cord blood samples were collected at delivery. FA composition was analyzed using gas chromatography. Selected FA indices and the transplacental transport index (TTI) were calculated. Statistical analyses included group comparisons, multivariable models adjusted for maternal age and pre-pregnancy BMI, and false discovery rate correction. Results: Modest differences were observed in selected fatty acids and FA indices, particularly palmitoleic acid (C16:1) and the C16:1/C16:0 ratio. Principal component analysis suggested partial separation between groups, although substantial overlap was present. A difference in transplacental transport was observed for α-linolenic acid; however, high variability was noted. No consistent associations between reported dietary patterns and fatty acid composition of circulating serum lipids were identified. Conclusions: This exploratory study suggests potential differences in fatty acid composition and selected indices in GDM; however, findings should be interpreted with caution. The observed patterns may reflect late-pregnancy metabolic adaptations rather than causal mechanisms. Further studies in larger and more diverse populations are required to confirm these findings.

Background: Continuous glucose monitoring (CGM) has changed the clinical practice in diabetes management during pregnancy; however, its application during caesarean section remains understudied. This feasibility study evaluates the performance, reliability, and clinical utility of two CGM systems—FreeStyle Libre 2 and Medtronic Guardian Connect—during caesarean delivery and the early postpartum period in a patient with pregestational diabetes mellitus (PGDM). Methods: A prospective, single-patient study was conducted. A 32-year-old woman with type 1 diabetes underwent elective caesarean section at 38 weeks of gestation. Both CGM systems were applied over 18 h prior to surgery and monitored continuously through the intraoperative and five-day postpartum period. Glucose data, device performance, and usability were assessed. Results: Both CGM systems provided uninterrupted, high-quality glucose data throughout the perioperative period, including during spinal anaesthesia, surgical manipulation, and postoperative recovery. No sensor displacement nor signal loss occurred. Glycaemic readings remained within the normoglycaemic range (90–100 mg/dL) during surgery, with mild elevations observed during anaesthesia initiation. Postoperatively, both systems showed comparable glucose trends, with slightly lower readings from FreeStyle Libre 2. Conclusions: CGM is feasible and reliable during caesarean section in PGDM patients. These findings support the integration of CGM into obstetric surgical care and highlight the need for larger studies to validate clinical benefits.