Feasibility of pulse oximetry screening for critical congenital heart defects in homebirths

Pulse Oximetry Screening for Critical Congenital Heart Defects in Newborn Babies

Pulse oximetry screening (POS) was first described over 20 years ago. However, in recent years, major clinical trials have demonstrated consistent test accuracy for the detection of critical congenital heart defects (CCHD). International uptake of POS has progressed well over the last 10 years with most major high-income countries now recommending screening. This review describes the evidence base which has led to this, the current debate regarding choice of screening algorithm, and the future areas for further research.

Prenatal Diagnosis of Congenital Heart Disease and Voluntary Termination of Pregnancy: A Population-Based Study in Qingdao, China

Objective

The outcomes of fetuses with isolated congenital heart disease (CHD) diagnosed prenatally have not been investigated in a population-based study in China. This population-based study aimed to evaluate the rate of voluntary termination of pregnancy after the prenatal diagnosis of isolated CHD in Qingdao, China.

Methods

This was a population-based retrospective study in which data were collected from all pregnant women in Qingdao (eastern China) from August 2018 to July 2020; fetal data, maternal data and data on pregnancy outcomes were extracted from medical records regarding prenatal diagnosis of CHD. The inclusion criteria were as follows: pregnant women or their husbands who had a household registration in Qingdao and who underwent regular prenatal screening in Qingdao. The exclusion criterion was the failure to sign an informed consent form. Counseling for all parents of fetuses with CHD was provided by a multidisciplinary team of experienced pediatric cardiologists, obstetricians, geneticists, etc. According to the type and severity of CHD, the pregnancy termination rate was analyzed.

Results

Among the 126,843 pregnant women, 1299 fetuses with a prenatal diagnosis of CHD were included in the study. Among the included fetuses, 1075 were diagnosed with isolated CHD, and the overall pregnancy termination rate was 22.8%. Termination rates varied according to the complexity of CHD (low complexity vs moderate complexity, P=0.000; low complexity vs high complexity, P=0.000; moderate complexity vs high complexity, P=0.000), with rates of 6.0% for low complexity, 54.2% for moderate complexity, and 99.1% for high complexity. The decision to terminate the pregnancy in cases of isolated CHD was unrelated to maternal age (P=0.091) but was related to gestational age (p=0.000).

Conclusion

In Qingdao, 99.1% of parents whose fetuses were diagnosed with isolated high-complexity CHD chose to voluntarily terminate the pregnancy. The pregnancy termination rate increased with increasing complexity of prenatally diagnosed CHD.

Comorbidities in congenital heart disease: different patterns in childhood and adulthood

BACKGROUND

Existing studies were no exploration of the association between congenital heart disease (CHD) in children and comorbidities. This study was to assess the prevalence and number of comorbidities in CHD among children and adults, and to compare the comorbidity patterns by children and adults using association rule analysis.

METHODS

Patients identified by the International Classification of Diseases, Ninth Revision (ICD-9) code in the Medical Information Mart for Intensive Care III (MIMIC-III) 2001-2012 and MIMIC-IV 2008-2018 were included in this cross-sectional study. Association rule analysis was used to explore associations between CHD and comorbidities in children and adults using values of support (%), confidence (%), and lift.

RESULTS

Among 60,400 eligible patients, 1.54% of adults had CHD and 0.83% of adults had CHD with at least one comorbidity, 13.79% had CHD and 12.37% had CHD with at least one comorbidity in children. The most common comorbidities were circulatory system diseases (53.78%), endocrine diseases (35.76%), and respiratory system diseases (23.46%) in adults with CHD, and the most common comorbidities were perinatal diseases (87.50%) in children with CHD. The comorbidity rate was 90.19% and 56.68% in children and adults, respectively. In children, perinatal diseases, circulatory system diseases, and endocrine diseases had the highest prevalence. The incidence of circulatory system diseases, perinatal diseases and endocrine diseases in CHD adults was confidence = 31.56%, 36.11%, and 23.23%, respectively. Perinatal diseases were common comorbidities among all CHD severity groups in children and adults.

CONCLUSION

The prevalence of comorbidities in children with CHD was higher than that in adults with CHD. The most common comorbidities were perinatal diseases and endocrine diseases among children and adults with CHD, respectively. Our study provided insights into comorbidity patterns in children and adults with CHD.

Temporal trends in routine predischarge pulse oximetry screening: 6 years' experience in a UK regional neonatal unit

OBJECTIVES

To evaluate the continued impact of pulse oximetry screening (POS) in a regional neonatal unit (NNU) and identify trends in screening outcomes in comparison with our previous experience.

DESIGN

Retrospective review of admissions between April 2013 and March 2019 (the current study) and comparison with previously published data (the 2014 study).

PATIENTS

All infants >34 weeks completed gestation admitted to NNU as a result of positive POS.

OUTCOME MEASURES

Indication for admission, diagnosis, investigations and management.

RESULTS

There were 49 375 livebirths and 253 NNU admissions as a result of positive POS (0.5% of livebirths; compared with 0.8% in 2014). 247/253 (97.6%) of those admitted had a significant diagnosis requiring medical intervention (compared with 79% in 2014) and the proportion of healthy babies (with transitional circulation) admitted decreased from 21% to 2.4%.22 (9%) babies admitted as a result of a positive POS were found to have a previously undiagnosed congenital heart defect (CHD) of which eight were critical CHDs (CCHDs). This accounted for 73% of all undiagnosed CCHD undergoing POS. The antenatal detection rate of CCHD was 75% compared with 46% in 2014. No baby died or collapsed on the postnatal ward during the study period. The proportion of babies with CCHD identified before discharge improved from 94% to 99%.

CONCLUSIONS

Routine POS, in addition to antenatal screening and postnatal examination, continues to contribute to the improvement of our overall CCHD detection rates. We have demonstrated an overall reduction in the admission of healthy babies and therefore workload following a positive test.

A Study on Clinical Screening of Neonatal Congenital Heart Disease in Jinjiang City

OBJECTIVE

This study explored the feasibility of congenital heart disease (CHD) screening by combining a percutaneous oxygen saturation (POX) test with cardiac auscultation method in neonates.

METHODS

POX tests and cardiac auscultation were used concurrently to screen 8305 neonates born in Jinjiang City Hospital between January 2016 and December 2018 for CHD. The positive screening results (positive POX or positive cardiac auscultation) were confirmed with echocardiography, while any false negative results were identified through follow-up and parent feedback. Sensitivity, specificity, positive/negative predictive values, Youden's index, and the area under the receiver operator characteristic curve (AUC) of the single use and combined use of the two methods (a POX test and auscultation) were calculated, and the results were compared.

RESULTS

Among 8305 neonates, 22 cases were positive for POX alone, of which 6 cases were diagnosed by echocardiography; 83 cases were positive for cardiac auscultation alone, of which 47 cases were diagnosed by echocardiography; and 8 cases were positive for both methods, all of which were confirmed by echocardiography. Four more cases were confirmed during follow-up. Sensitivity, specificity, and the positive and negative predictive values of combined screening were 93.85%, 99.37%, 53.98% and 99.95%, respectively, while Youden's index was 0.93, and the AUC was 0.966. Sixty-five cases of CHD were diagnosed, the total incidence being 7.82%, and a ventricular septal defect was found to be the most common type.

CONCLUSION

The combination of POX test and cardiac auscultation as a screening method for neonatal CHD can reduce missed diagnoses and increase the detection rate of CHD in newborn infants.

Pulse oximetry screening in a midwifery-led maternity setting with high antenatal detection of congenital heart disease

Aim

To assess local and individual factors that should be considered in the design of a pulse oximetry screening strategy in New Zealand's midwifery‐led maternity setting.

Methods

An intervention study was conducted over 2 years. Three hospitals and four primary maternity units participated in the study. Post‐ductal saturation levels were measured on well infants with a gestation of ≥35 weeks. Infant activity and age (hours) at the time of the test were recorded.

Results

Screening was performed on 16 644 of 27 172 (61%) eligible infants. The age at which the screening algorithm was initiated varied significantly among centres. The probability of achieving a pass result (saturations ≥95%) in the context of no underlying pathology ranged from .94 for an unsettled infant screened <4 hours of age to .99 (P < .001) when the test was performed after 24 hours on a settled infant. Forty‐eight (0.3%) infants failed to reach saturation targets: 37 had significant pathology of which three had cardiac disease.

Conclusion

Screening practices were influenced by the setting in which it was undertaken. Infant activity and age at the time of testing can influence saturation levels. Screening is associated with the identification of significant non‐cardiac pathology.

Pulse Oximetry Screening for Critical Congenital Heart Defects: A Life-Saving Test for All Newborn Babies

Congenital heart defects (CHD) are the commonest congenital malformations and remain a major cause of neonatal mortality and morbidity in the developed world[...]

Accuracy of Pulse Oximetry Screening for Critical Congenital Heart Defects after Home Birth and Early Postnatal Discharge

OBJECTIVE

To assess the accuracy of pulse oximetry screening for critical congenital heart defects (CCHDs) in a setting with home births and early discharge after hospital deliveries, by using an adapted protocol fitting the work patterns of community midwives.

STUDY DESIGN

Pre- and postductal oxygen saturations (SpO₂) were measured ≥1 hour after birth and on day 2 or 3. Screenings were positive if the SpO₂ measurement was <90% or if 2 independent measures of pre- and postductal SpO₂ were <95% and/or the pre-/postductal difference was >3%. Positive screenings were referred for pediatric assessment. Primary outcomes were sensitivity, specificity, and false-positive rate of pulse oximetry screening for CCHD. Secondary outcome was detection of noncardiac illnesses.

RESULTS

The prenatal detection rate of CCHDs was 73%. After we excluded these cases and symptomatic CCHDs presenting immediately after birth, 23 959 newborns were screened. Pulse oximetry screening sensitivity in the remaining cohort was 50.0% (95% CI 23.7-76.3) and specificity was 99.1% (95% CI 99.0-99.2). Pulse oximetry screening was false positive for CCHDs in 221 infants, of whom 61% (134) had noncardiac illnesses, including infections (31) and respiratory pathology (88). Pulse oximetry screening did not detect left-heart obstructive CCHDs. Including cases with prenatally detected CCHDs increased the sensitivity to 70.2% (95% CI 56.0-81.4).

CONCLUSION

Pulse oximetry screening adapted for perinatal care in home births and early postdelivery hospital discharge assisted the diagnosis of CCHDs before signs of cardiovascular collapse. High prenatal detection led to a moderate sensitivity of pulse oximetry screening. The screening also detected noncardiac illnesses in 0.6% of all infants, including infections and respiratory morbidity, which led to early recognition and referral for treatment.

Pulse Oximetry Screening Adapted to a System with Home Births: The Dutch Experience

Neonatal screening for critical congenital heart defects is proven to be safe, accurate, and cost-effective. The screening has been implemented in many countries across all continents in the world. However, screening for critical congenital heart defects after home births had not been studied widely yet. The Netherlands is known for its unique perinatal care system with a high rate of home births (18%) and early discharge after an uncomplicated delivery in hospital. We report a feasibility, accuracy, and acceptability study performed in the Dutch perinatal care system. Screening newborns for critical congenital heart defects using pulse oximetry is feasible after home births and early discharge, and acceptable to mothers. The accuracy of the test is comparable to other early-screening settings, with a moderate sensitivity and high specificity.

Pulse oximetry screening for critical congenital heart defects

BACKGROUND

Health outcomes are improved when newborn babies with critical congenital heart defects (CCHDs) are detected before acute cardiovascular collapse. The main screening tests used to identify these babies include prenatal ultrasonography and postnatal clinical examination; however, even though both of these methods are available, a significant proportion of babies are still missed. Routine pulse oximetry has been reported as an additional screening test that can potentially improve detection of CCHD.

OBJECTIVES

• To determine the diagnostic accuracy of pulse oximetry as a screening method for detection of CCHD in asymptomatic newborn infants• To assess potential sources of heterogeneity, including:○ characteristics of the population: inclusion or exclusion of antenatally detected congenital heart defects;○ timing of testing: < 24 hours versus ≥ 24 hours after birth;○ site of testing: right hand and foot (pre-ductal and post-ductal) versus foot only (post-ductal);○ oxygen saturation: functional versus fractional;○ study design: retrospective versus prospective design, consecutive versus non-consecutive series; and○ risk of bias for the "flow and timing" domain of QUADAS-2.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 2) in the Cochrane Library and the following databases: MEDLINE, Embase, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Health Services Research Projects in Progress (HSRProj), up to March 2017. We searched the reference lists of all included articles and relevant systematic reviews to identify additional studies not found through the electronic search. We applied no language restrictions.

SELECTION CRITERIA

We selected studies that met predefined criteria for design, population, tests, and outcomes. We included cross-sectional and cohort studies assessing the diagnostic accuracy of pulse oximetry screening for diagnosis of CCHD in term and late preterm asymptomatic newborn infants. We considered all protocols of pulse oximetry screening (eg, different saturation thresholds to define abnormality, post-ductal only or pre-ductal and post-ductal measurements, test timing less than or greater than 24 hours). Reference standards were diagnostic echocardiography (echocardiogram) and clinical follow-up, including postmortem findings, mortality, and congenital anomaly databases.

DATA COLLECTION AND ANALYSIS

We extracted accuracy data for the threshold used in primary studies. We explored between-study variability and correlation between indices visually through use of forest and receiver operating characteristic (ROC) plots. We assessed risk of bias in included studies using the QUADAS-2 tool. We used the bivariate model to calculate random-effects pooled sensitivity and specificity values. We investigated sources of heterogeneity using subgroup analyses and meta-regression.

MAIN RESULTS

Twenty-one studies met our inclusion criteria (N = 457,202 participants). Nineteen studies provided data for the primary analysis (oxygen saturation threshold < 95% or ≤ 95%; N = 436,758 participants). The overall sensitivity of pulse oximetry for detection of CCHD was 76.3% (95% confidence interval [CI] 69.5 to 82.0) (low certainty of the evidence). Specificity was 99.9% (95% CI 99.7 to 99.9), with a false-positive rate of 0.14% (95% CI 0.07 to 0.22) (high certainty of the evidence). Summary positive and negative likelihood ratios were 535.6 (95% CI 280.3 to 1023.4) and 0.24 (95% CI 0.18 to 0.31), respectively. These results showed that out of 10,000 apparently healthy late preterm or full-term newborn infants, six will have CCHD (median prevalence in our review). Screening by pulse oximetry will detect five of these infants as having CCHD and will miss one case. In addition, screening by pulse oximetry will falsely identify another 14 infants out of the 10,000 as having suspected CCHD when they do not have it.The false-positive rate for detection of CCHD was lower when newborn pulse oximetry was performed longer than 24 hours after birth than when it was performed within 24 hours (0.06%, 95% CI 0.03 to 0.13, vs 0.42%, 95% CI 0.20 to 0.89; P = 0.027).Forest and ROC plots showed greater variability in estimated sensitivity than specificity across studies. We explored heterogeneity by conducting subgroup analyses and meta-regression of inclusion or exclusion of antenatally detected congenital heart defects, timing of testing, and risk of bias for the "flow and timing" domain of QUADAS-2, and we did not find an explanation for the heterogeneity in sensitivity.

AUTHORS' CONCLUSIONS

Pulse oximetry is a highly specific and moderately sensitive test for detection of CCHD with very low false-positive rates. Current evidence supports the introduction of routine screening for CCHD in asymptomatic newborns before discharge from the well-baby nursery.

Newborn pulse oximetry screening in practice

The concept of using pulse oximetry (PO) as a screening test to identify newborn babies with critical congenital heart defects (CCHD) before life-threatening collapse occurs has been debated for some time now. Several recent large studies have consistently shown that PO screening adds value to existing screening techniques with over 90% of CCHDs detected. It can also help identify newborn babies with low oxygen saturations due to infection, respiratory disease and non-critical CCHD. Many countries have now introduced PO screening as routine practice, and as screening gains more widespread acceptance in the UK, we have focused more on the practical aspects of screening in this article. This includes case reports to demonstrate how the different screening modalities for CCHD work together and the experience of hospitals that have already introduced PO screening programmes (Birmingham Women's Hospital and others). Issues discussed include how and when to screen babies in hospital, what to do with a positive screen and how to screen babies born at home. The UK National Screening Committee is currently investigating the potential feasibility of routine PO screening in the UK, and so it is perhaps a suitable time for individual hospitals to consider the possibility of introducing such screening in their maternity units.

Reliability and Validity of a Smartphone-Paired Pulse Oximeter for Screening of Critical Congenital Heart Defects in Newborns

BACKGROUND

Barriers to widespread implementation of pulse oximetry screening of critical congenital heart defects (CCHD) in newborns include increasing trends of out-of-hospital births and cost of equipment. In recent years, smartphone-compatible pulse oximeters have appeared on the market, but the validity of such devices in the setting of CCHD screening has not been evaluated.

OBJECTIVES

To compare the performance in CCHD screening of a smartphone-paired pulse oximeter (Masimo iSpO2-Rx™) and a hospital-grade pulse oximeter (Masimo Radical-7™).

METHODS

Preductal (right hand) and postductal (either foot) saturations were determined in a population of 201 term newborns by 2 independent teams, one using the Radical-7 and the other using the iSpO2-Rx. Bland-Altman analysis was applied to calculate mean bias and 95% limits of agreement between the 2 pulse oximeters.

RESULTS

For the preductal oxygen saturation, the mean bias (Radical-7 minus iSpO2-Rx) was -0.08 (SD 1.76) and the lower and upper limits of agreement were -3.52 and 3.36, respectively. For the postductal oxygen saturation, the mean bias was -0.11 (SD 1.68) and the lower and upper limits of agreement were -3.49 and 3.18, respectively. In addition, the iSpO2-Rx provided reliable measurements of saturations below 95% in a group of 12 infants admitted to the neonatal intensive care unit.

CONCLUSIONS

Our data suggest that CCHD screening with the Masimo iSpO2-Rx is feasible and accurate. The use of reliable smartphone-paired pulse oximeters may contribute to the extension of CCHD screening to home births and low resource settings.

Critical congenital heart disease screening

Critical congenital heart disease (CCHD) is a heart lesion for which neonates require early surgical intervention to survive. Without intervention, the rates of mortality and survival with significant disability are extremely high. Early diagnosis can potentially improve health outcomes in newborns with CCHD. Until recent years, no routine screening protocol existed. In the last few years, pulse oximetry screening for CCHD in newborns has been added to the list of recommended uniform screening panels and advocated by several health-care authorities. A positive screening test result warrants an echocardiogram to evaluate for CCHD. Newborn screens do not usually require parental consent. However, most of the states mandates in the United States include a statement allowing exemption from the screen on the basis of parental religious or personal beliefs.