Pulse Oximetry During the First 24 Hours as a Screening Tool for Congenital Heart Defects

Although screening for congenital heart defects (CHD) relies mainly on antenatal ultrasonography and clinical examination after birth, life-threatening cardiac malformations are often not diagnosed before the patient is discharged.

To assess the use of routine pulse oximetry in the delivery room and at 24 hours postpartum, and to study its feasibility as a screening test for CHD.

In this prospective study, all infants born in "Cuza Voda" Maternity Hospital, Iasi, Romania, were enrolled over a thirteen-month period. Preductal oximetry was assessed during the first hour, and postductal oximetry was evaluated at twenty-four hours postpartum. Data were then analyzed to establish the sensitivity and specificity of pulse oximetry, as a screening test for CHD.

5406 infants were included in the study, with a mean gestational age of 38.2 weeks and a mean birth weight of 3175 grams. During the first minute, blood oxygen saturation varied between 40% and 90% and at 24 hours of life, it ranged between 90% and 100%. Following oximetry assessment, 14 infants with critical CHD were identified. Blood oxygen saturation values in infants with CHD were lower throughout the entire period of evaluation. Pulse oximetry had good sensitivity and specificity at 1 hour (Se=87.5%, Sp=95.5%) and 24 hours (Se=92.5%, Sp=97.4%) for the diagnosis of CHD. Blood oxygen saturation values at one minute, 1 hour and 24 hours are strong discriminative parameters for the early diagnosis of CHD.

Routine pulse oximetry during the first 24 hours postpartum represents an early indicator of CHD to facilitate timely intervention. Pulse oximetry provides excellent sensitivity and specificity and has tremendous potential as a standard screening test for CHD during the first 24 hours of life.