[Birth hypoxia]

Evaluation of the commonly used laboratory and clinical parameters of the newborn shortly after birth. Check thresholds acidemia, and in relation to the method of termination of pregnancy.

Retrospective epidemiological study.

Department of Obstetrics and Gynecology, University Hospital, Olomouc.

Of the 26,869 children born in the years 2000 to 2013 Inclusion criteria (complete clinical and laboratory findings after birth) fulfill 23,471 (87.4%) neonates. Methods for evaluation of newborns included Apgar score calculation and arterial umbilical cord blood pH and lactate analysis.

A total of 0.7% (157) of the neonates had severe acidosis pH below 7.00 arterial umbilical cord blood, its prevalence varies annually between 0.1 to 1.1%. Cutoff lactate in relation to pH < 7.00 was 6.3 mmol/l (n = 23 471, the sensitivity of 92.99%, specificity 92.15%, AUC = 0.972). For children of low weight < 2500 g the cutoff value is lower, 5.3 mmol/l (n = 2592, 89.66% sensitivity, specificity 91.10% AUC = 0.912). Suprathreshold lactate values was 8.4% (1977) newborns. Correlation of pH and lactate to Apgar evaluation is very low and in the range from 1 to 10 minutes gradually decreases. Worse Apgar evaluation in children of low birth weight do not correspond to laboratory findings acidosis, which is probably related to prematurity and lower energy reserves. Operating cesarean births in particular accounts for more than half of those with worse clinical findings Apgar and pH <7.00, but only 30% supratreshold lactate values. Also worse clinical evaluation after caesarean section is not in accordance with the laboratory findings. Vaginal surgery, especially forceps have a significant share of severe acidosis than cesarean, regardless of their frequency. Risk factor of forceps to pH less 7.00,OR = 9.28 (5.39 -15.77), P = 0.0000000, while caesarean to pH less 7,00 had OR = 1.52 (1.08 to 2.14), P = 0.01408156.

The results obtained confirm that acidosis after birth is quite common, although they may not have response on the clinical condition of the newborn after birth. Evaluation of Apgar is little objective for the detection of hypoxia during birth and is influenced by the immaturity of newborn and method of delivery. Lactate levels may contribute to an objective assessment of hypoxia during birth. Values above 6.3 mmol/l can be considered an important indicator of newborn acidosis and birth hypoxia.