[Evaluation of routine gas determinations in umbilical cord blood at cesarean section].

From 1985 to 1989, analysis of the umbilical cord blood gas in 546 cases of cesarean section delivery under spinal anesthesia was carried out to evaluate its relationship with neonatal asphyxia, and the following results were obtained. (1) The UApH of a normal newborn with an Apgar score > 7 was 7.28 +/- 0.04. Acidosis occurred in 33.3% of the infants born with an Apgar score < 7, but the incidence was only 3.9% in those with an Apgar score > 7. Sixteen% of the acidosis was metabolic and 84% belonged to the mixed type. The UApH and Apgar scores were most significantly related. (2) The abnormal UVpH was 4.9% (< M - 2SD). (3) There was no significant difference in UApH between cesarean section performed before and after the onset of labor. (4) The short term morbidity included: one death, 2 cases of convulsions, 2 cases of cerebral edema, and one case of periventricular leukomalacia. (5) The long term morbidity in the 29 cases referred to NICU included: 18 cases of normal growth, 2 cases of severe cerebral palsy, 3 cases of mild cerebral palsy, and 6 cases of mental retardation. (6) In view of the long term morbidity of the newborn, as seen in the correlation between the Apgar score and UApH, it was considered that, the critical points in neonatal asphyxia were Apgar score < or = 3 and UApH < 7.10. My results suggested that the umbilical cord blood gas analysis was helpful for the diagnosis of neonatal asphyxia, and the prognosis of the newborn.