[Impact of the duration of labor in the neonatal state measured by arterial blood gas at birth.].

Objective: The duration of labor has become a central axis of its clinical management, most of the studies that analyze its relationship with the neonatal state focus on indirect tests such as the Apgar test or admissions to the NICU. The aim of the study was to analyze the repercussions of the duration of labor on the condition of the neonates without added risk factors through a direct analysis test such as the umbilical artery blood gas test at birth.

Methods: An observational, analytical, retrospective, and prevalence study was conducted on a sample of 286 infants no previous risk factors obtained from the computerized clinical registry. For a confidence level of p<0.05, parametric tests such as Pearson's correlation coefficient and Chi-square were applied.

Results: Showed a significant negative correlation between umbilical artery pH values and delivery times (Dilation: R=-0.207; p=0.002 - Expulsive: R=-0.150; p=0.027 - Total delivery: R=-0.181; p=0.006). Presenting deliveries with times above the mean greater possibilities of fetal acidosis and hypercapnia in dilation (pH: OR=3.10; IC 1.64-5.51 - pCO2: OR=2.19; IC 1.23-3.89), the expulsive (pH: OR=2.24; IC 1.21-4.16 - pCO2: OR=1.77; IC 0.98-3.22) and the total duration (pH: OR=3.36, IC 1.84-6.13- pCO2: OR=2.53; IC 1.44-4.46).

Conclusions: A significant association is was found between the prolongation of labor times and acidosis and neonatal hypercapnia.