Objective :  To evaluate the effectiveness of predischarge pulse oximetry as screening for critical congenital heart disease(CCHD) in Term and near term newborns.

Methods : This was a prospective case control study conducted in the Neonatal intensive care unit and postnatal wards of a tertiary hospital ,Delhi.The study period was from june 2014 to November 2015,and followed up to 3 months.Inclusion criteria :–Healthy near term (35 to 37 completed weeks of gestation) and term (37 to 42 completed weeks of gestation) neonates .Exclusion criteria :–Neonates with any congenital malformation detected antenatally,Neonates requiring care in the neonatal intensive care unit., Severe IUGR and  Maternal intake of drugsapart from the nutritional supplements.The pulse Oximetry Probes were applied to right upper limb (Preductal) and right lower limb (Postductal) in a calm /awake baby for about 3 min for  saturations and their difference was recorded. A mean of three readings were taken. Oxygen saturation  SPo2  <95% or differential saturation >3%was considered screen positive and sent for echocardiography for confirmation.

Statistical analysis : Data was entered in a predesigned proforma in MicrosoftExcel. The data was then analyzed statistically using Stata software version 11(Stata Corp, College Station, TX). Continuous data with normal distribution was analyzed by student t test and non–normally distributed data by Wilcoxon rank sum test (Mann–Whitney). Categorical data was analyzed by chi–square or Fisher exact test. A P value of <0.05 was taken as significant.

Results :

Of the 4100 term and near term neonates screened 427(10.4%) babies were screen  positiveand 3273(89.6%) babies screen negative  with pulse oximetry. Total of 42 newborns screen positive  for detection of CHD by SPO2 constituted 9.8% (42/427). out of42 screen positive newborns for SPO2 . Echocardiography examination in these newborns revealed congenital heart disease in 59.5% (25/42).The sensitivity and specificity of SPO2 for detection of CCHD was  80% and  99% respectively ,whereas positive predictive value(PPV) and negative predictive value(NPV)was  9.5% and 100% respectively. P valuewas significant (<0.0001) .

Conclusion :The technique of pulse oximetry is simple , reliable and an effective method of screening for detection of CCHD .