Effects of uncomplicated vaginal delivery and epidural analgesia on fetal arterial acid-base parameters at birth in gestational diabetes

Aim: To investigate the effects of uncomplicated vaginal delivery and epidural analgesia on fetal acid-base parameters in women with gestational diabetes (GDM) compared with controls. Methods: A retrospective case-control study of 142 women with gestational diabetes and 284 controls. To evaluate the effect of diabetes and analgesia on acid-base status correcting for potential confounders we used ordered logistic equations including quartiles of fetal arterial acid-base parameters collected at birth as outcomes and categories of diabetes and epidural analgesia as explanatory variables. Results: In the GDM group cord base deficit (-2.63. mmol/l, interquartile range [IQR]. = 4.2 to -0.65. mmol/l vs. -1.9. mmol/l, IQR. = -3.3 to -0.2. mmol/l, p= 0.009, odds ratio (OR). = 1.51, 95% confidence interval (CI). = 1.04-2.18) was lower and concentration of calcium higher (1.49. mmol/l, IQR. = 1.42-1.56. mmol/l vs. 1.47. mmol/l, IQR. = 1.41-1.51. mmol/l, p= 0.009, OR. = 1.69, 95% CI. = 1.12-2.56) compared with controls. Epidural analgesia in the GDM group was associated with reduced cord concentration of glucose (84.0. mg/dl [4.7. mmol/l], IQR. = 70-103.3. mg/dl vs. 92.5. mg/dl [5.1. mmol/l], IQR. = 76.5-121.8. mg/dl, p= 0.004), lactate (2.65. mmol/l (IQR. = 1.80-4.20) vs. 3.70. mmol/l (IQR. = 2.90-5.55. mmol/l), p= 0.002) and less pronounced base deficit (-2.05. mmol/l, IQR. = -3.90 to -0.17. mmol/l vs. -2.8, IQR. = -5.57 to -1.05. mmol/l, p= 0.01, OR. = 0.7, 95% CI. = 0.49-0.99). Conclusions: In uncomplicated pregnancies and deliveries, well-controlled gestational diabetes mellitus has potentially significant detrimental effects on fetal acid-base status at birth. Epidural analgesia reduces cord arterial glucose and lactates.