Objective: This study aimed to evaluate the necessity of cord arterial blood gas analysis in cases without fetal distress and normal Apgar score.
Materials and methods: The cord arterial blood gas analysis and the 1- and 5-minute Apgar scores data of 1438 cases were evaluated. Newborns with fetal distress, neonates requiring cardiopulmonary resuscitation in the delivery room, congenital anomalies, severe and moderate acidemia (pH ≤7.1 at cord arterial blood gas analysis), and pre- and post-term newborns are excluded. Following cord arterial blood gas analysis, threshold values were accepted as abnormal pH <7.2, base excess ≥ -6 mmol/L, lactate ≥ 5 mmol/L, bicarbonate < 18 mmol/L, and partial pressure of carbon dioxide ≥ 50 mmHg. We evaluated the correlation between cord arterial blood gas analysis and 1- and 5-minute Apgar scores.
Results: There was a significant correlation between both 1- and 5-minute Apgar scores and cord arterial blood gas analysis values such as pH, lactate, and partial pressure of carbon dioxide (P < .001). In addition, a significant correlation was found between the 5-minute Apgar score of <7 and some cord arterial blood gas analysis abnormal threshold values (pH, bicarbonate, base excess) (P < .001). We found that some patients with mild acidemia had 1- and 5-minute Apgar scores of ≥7 in 1.9% and 2% of cases, respectively.
Conclusion: The 5-minute Apgar score of 7 or higher may not be sufficient to verify the wellbeing of a newborn. Relying only on the Apgar scores may create the risk of missing some newborns with mild metabolic acidosis. The necessity of routine cord arterial blood gas analysis should be considered in prospective studies even if there are no signs of fetal distress and Apgar score ≥7.