Prevalence of Critical Congenital Heart Disease Detected in the Pulse Oximetry Test in Asymptomatic Newborns, ≥35 Gestational Weeks, in a Maternity in Southern Brazil

Abstract

Background: Congenital heart diseases (CHD) are one of the most prevalent malformations, and the screening tests to identify critical congenital heart disease (CCHD) is the pulse oximetry test, with subsequent investigation and treatment.Objective: To quantify positive pulse oximetry tests and verify the prevalence of CCHD detected by it in asymptomatic newborns, ≥35 gestational weeks, in a Brazilian maternity hospital.Methodology: This is an observational, retrospective, quantitative, analytical and cross-sectional study, conducted from October 2020 to May 2022, in a maternity hospital in southern Brazil, through the collection of records of positive oximetry pulse tests, following the norms of screening CCHD test of the Brazilian Society of Pediatrics (SBP), after they were evaluated with echocardiography for confirmation or exclusion of CHD.Results: A total of 5,667 newborns were evaluated in this study, according to the inclusion criteria; 0.17% (n = 10) had a positive pulse oximetry test. Regarding the results of the echocardiography of the neonates with a positive test, two were normal, seven were cases of patent foramen ovale (PFO), and one was a case (0,017%) with interatrial communication (IAC) diagnosis. In the same period, five neonates with CCHD were born, symptomatic, diagnosed by physical examination, and referred to neonatal intensive care units (NICU) before taking the neonatal cardiac screening (< 24 hours of life). Conclusion:The prevalence of positive pulse oximetry tests was 0.17% and none CCHD was detected. Five cases of CCHD were born in this period, but they were diagnosed before the recommend time to perform the screening test.

Is Pulse Oximetry a Reliable Method for Screening for Critical Congenital Heart Disease in Asymptomatic Neonates at 35 Weeks or More of Gestation?

“…5 The high mortality rate of CCVMs is due to the lack of prenatal and perinatal diagnoses, which hinders or delays effective treatment and results in death. 1,3,[7][8][9] D u r i n g p r e g n a n c y , e x a m i n a t i o n s s u c h a s second trimester morphology ultrasound and fetal echocardiography aid in diagnosis. However, the sensitivity of these methods may be as low as 80% because of the transition from fetal to neonatal circulation at birth.…”

“…It has a sensitivity of 70% and specificity of 99.9%. 1,5,12 Due to variability in neonatal oxygen saturation, pulse oximetry might produce falsepositive results if performed before 24 hours of life. 5 An abnormal pulse oximetry result warrants continued hospitalization of the newborn and the performance of transthoracic echocardiography for diagnostic confirmation of CCVMs.…”

“…Transthoracic echocardiography has proven to be important for the early detection of cardiac morphologic abnormalities in asymptomatic newborns. 1 According to a meta-analysis of 46,965 neonates, pulse oximetry screening had a sensitivity and specificity of 0.82 (95% confidence interval [CI], 0.53 to 0.95) and 0.97 (95% CI, 0.57 to 1.00), respectively, and transthoracic echocardiography had a concordance of 0.92 (95% CI, 0.89 to 0.94) for CCHD. 13 In a United Kingdom cohort study of 20,055 newborns followed up to 1 year of age, the accuracy of pulse oximetry testing compared with transthoracic echocardiography was estimated to be 13.33% (95% CI, 8.9% to 18.92%) for critical malformation.…”