The role of acidosis at birth in the development of hyaline membrane disease.

To test the hypothesis that intarpartum acidosis has a role in the etiology of hyaline membrane disease (HMD), blood was collected from the umbilical artery (UA) at birth from 110 premature infants and analyzed for hydrogen ion concentration ([H+]), PCO2, standard bicarbonate, and lactic acid. The infants were followed until a definite diagnosis was made of HMD (33 infants), type II respiratory distress syndrome (16 infants) or the absence of respiratory distress (61 infants). In general, infants with HMD were more premature and had lower Apgar scores than nondistressed infants; however, there were no significant differences between the two groups in any acid-base measurement. Only in those patients of 32 to 37 weeks' gestational age was it possible to detect a significant increase in UA [H+] in infants with HMD compared to those without respiratory distress. There was evidence that the reduced Apgar score of infants with HMD may be due to immaturity and abnormal pulmonary function secondary to lung disease. It is concluded that acidosis at birth is not a factor in the development of HMD except possibly in more mature infants.