Live-Born Major Congenital Heart Disease in Denmark: Incidence, Detection Rate, and Termination of Pregnancy Rate From 1996 to 2013

Importance

The occurrence of major congenital heart disease (CHD) is affected by several variables. Determining the development of the true incidence is critical to the establishment of proper treatment of these patients.

Objective

To evaluate time trends in incidence, detection rate, and termination of pregnancy (TOP) rate of major CHD in fetuses in Denmark and assess the influence of the introduction of general prenatal screening in 2004.

Design, Setting, and Participants

Nationwide, population-based, retrospective observational study in Denmark from 1996 to 2013 that included a consecutive sample of 14 688 live-born children and terminated fetuses diagnosed as having CHD. Patient records on TOP and children with major CHD were reviewed to validate the diagnoses. Major CHD included univentricular heart, transposition of the great arteries, congenitally corrected transposition of the great arteries, truncus arteriosus, interrupted aortic arch, atrioventricular septal defects, double outlet right ventricle, coarctatio of the aorta, Ebstein anomaly, pulmonary atresia with ventricular septal defect, pulmonary atresia with intact ventricular septum, and tetralogy of Fallot. Data were analyzed between January 2017 and March 2018.

Main Outcomes and Measures

Temporal changes in incidence, detection rate, and TOP of major CHD.

Results

Of 14 688 children and fetuses diagnosed with CHD, 2695 (18.4%; 95% CI, 17.8-19.1) had major CHD. A total of 7131 boys (1304 with major CHD) and 6926 girls (920 with major CHD) were included, with a median age of 11 years (interquartile range, 6-15 years). During the study period, the live-birth incidence of CHD was constant at 1.22% (95% CI, 1.18-1.26), whereas it decreased for major CHD. When including TOP, the incidence of major CHD did not change over time. The detection rate of major CHD increased from 4.5% (95% CI, 1.2-7.8) to 71.0% (95% CI, 63.3-78.7) (P < .001). At the end of the study, all cases of double outlet right ventricle, Ebstein anomaly, congenitally corrected transposition of the great arteries, and pulmonary atresia with ventricular septal defect were detected prenatally, whereas coarctation of the aorta had the lowest detection rate (21.7%; 95% CI, 3.5-40.0). The TOP rate increased from 0.6% (95% CI, -0.6 to 1.9) to 39.1% (95% CI, 30.9-47.4) (P < .001) among all major CHD. For prenatally diagnosed major CHD, 57.8% of cases were terminated and the proportion did not change significantly throughout the study. Diagnoses leading to TOP included all major CHD diagnoses.

Conclusions and Relevance

Detection rates of major CHD improved during the study. This has led to increased TOP rates, with a subsequent 39% decrease in the live-birth incidence of major CHD.

The accuracy of prenatal diagnosis of major congenital heart disease is increasing

Regular audit of results of prenatal screening for congenital heart disease (CHD) is crucial to ensure reliable prenatal diagnosis. We aimed to assess the accuracy of prenatal diagnosis of major CHD between 1996 and 2013. During the study period, prenatal detection of major CHD improved from 4.5% to 71.0% (p<.001). Prenatal diagnoses on 628 live born children and terminated pregnancies were compared with postnatal findings or autopsy reports. The proportion of correct diagnoses increased throughout the study period from 42.9% in 1996 and reached 88.2% in 2013 (p<.001). A total of 32 foetuses with suspected major CHD were terminated though no major CHD was found at autopsy. In these pregnancies, termination was mainly performed due to other anomalies in the foetus.Along with improved detection of major CHD, the validity of a prenatal diagnosis is increasing. No cases of misinterpreted major CHD resulted in the termination of a healthy foetus in this study.Impact statementWhat is already known on this subject? Prenatal diagnosis of isolated congenital heart disease (CHD) correlates well with lesions found during autopsy performed in terminated foetuses. Few studies have assessed the accuracy of prenatal diagnosis of major CHD in live born children, cases with associated anomalies and the time trend in validity.What the results of this study add? This study illustrates that the validity of prenatal diagnosis of major CHD is increasing. Prenatal diagnoses in terminated pregnancies as well as in live born children is high except for coarctation of the aorta and atrioventricular septal defects. Chromosomal anomalies are associated with lower accuracy of prenatal diagnosis.What the implications are of these findings for clinical practice and/or further research? Prenatal diagnosis is an accurate tool for detecting major CHD. Misinterpretation has not led to the termination of a healthy foetus; however, this study illustrates that vigilant care should be placed on the cardiac evaluation when termination is considered due to the cardiac defect.

Mortality and morbidity of major congenital heart disease related to general prenatal screening for malformations

BACKGROUND

Major congenital heart diseases (CHD) often demand intervention in the neonatal period. Prenatal diagnosis may improve mortality by eliminating the diagnostic delay; however, there is controversy concerning its true effect. We aimed to evaluate the effect of general prenatal screening on prognosis by comparing a period without general prenatal screening to a period with general prenatal screening.

METHODS

We conducted a nationwide retrospective study including live born children and terminated fetuses diagnosed with major CHD. Prenatal screening was recommended only in high risk pregnancies between 1996 and 2004, whereas general prenatal screening was recommended between 2005 and 2013. We assessed the influence of general prenatal screening on all-cause mortality, cardiac death, preoperative and postoperative 30-day mortality and complication rate.

RESULTS

1-year mortality decreased over both periods, but the decrease was greater in the screening period (Odds ratio 0.92 (CI 0.83-1.00), p = 0.047). Prenatal detection of major CHD was associated with cardiac death in the period without general screening (Hazard Ratio 2.40 (CI 1.72-3.33), p < 0.001), whereas there was no significant association once general screening was implemented. Similarly, the association between prenatal diagnosis and pre- and postoperative mortality found in the period without general screening was insignificant after the implementation of general screening.

CONCLUSION

Mortality in major CHD decreased throughout the study, especially in the period with general prenatal screening. However, comparing a prenatally diagnosed group with a postnatally diagnosed group is vulnerable to selection bias and proper interpretation is difficult.

[In-utero treatment of hypoplastic left heart syndrome]

In-utero treatment of fetal aortic stenosis (AS) may prevent hypoplastic left heart syndrome. A girl was diagnosed prenatally with severe AS and was referred to the Women's and Children's Hospital in Linz, Austria, where she underwent an intrauterine valvuloplasty of the aortic valve. Postnatally, the girl was given prostaglandin and operated a.m. Ross-Konno. An echocardiography at the age of four months showed a neoaorta without stenosis and insufficiency and a normal systolic function of the left ventricle. This treatment must be carefully considered when dealing with fetuses with AS.

A follow-up urine sample has limited value after treatment for urinary tract infection in children

INTRODUCTION

A routine follow-up urine sample (FUS) in the form of a midstream urine sample (MSU) is recommended after treatment for urinary tract infection (UTI) according to the Danish Paediatric Society (DPS) and "Lægehåndbogen" published by Danish Regions. We studied the effect of FUS with a focus on patients without symptoms at the time of FUS.

METHODS

Consecutive patients below 16.0 years treated for upper or lower UTI from 1 January 2009 to 31 December 2009 at Hvidovre Hospital in accordance with the guidelines of the department and the DPS. All patients were asked to provide a FUS within 21 days.

RESULTS

A total of 87 patients were treated for upper UTI: 59 girls and 28 boys, the median age was 1.1 year (range: 0.1-15.6 years); and 42 girls were treated for lower UTI, their median age was 8.2 years (range: 2.5-15.3 years). After treatment, the risk of a UTI was 0% (0/87) after upper UTI versus 19% (8/42) after lower UTI (Fisher's exact test (FE), p < 0.0001). Among those without symptoms at FUS, the risk of a UTI was 0% (0/75) (95% confidence interval (CI): 0-4.9%) after upper UTI versus 4% (1/26) (95% CI: 0.1-19.6%) after lower UTI (FE, p = 0.2754). The cost of requesting a FUS in patients without symptoms was 166 euro after treatment for upper UTI and 66 euro after treatment of lower UTI.

CONCLUSION

We do not recommend a FUS after treatment for UTI as the 95% CI of risk of missing UTI after treatment for upper UTI was below 5%. This strategy will save the patients/families and the health-care system. However, if a child has symptoms after treatment for UTI, it must be examined.

FUNDING

not relevant.

TRIAL REGISTRATION

The study was approved by the Danish Data Protection Agency (J. no. 2007-58-0015).

Impact of cleaning before obtaining midstream urine samples from children

INTRODUCTION

Microbiological documentation of one uropathogenic bacterium in significant numbers in urine from patients with typical symptoms is the gold standard for diagnosing urinary tract infection (UTI). Cleaning before collecting midstream urine (MSU) is reported not to reduce the risk of contaminating the sample and was therefore omitted at Hvidovre Hospital as from the autumn of 2006. We evaluate if no cleaning increased the risk of contamination in the Department of Paediatrics.

MATERIAL AND METHODS

A total of 1,858 patients aged 0-15 years who were suspected of UTI delivered two MSUs within 24 h. In 2004-2006 ("cleaning period"), 523 children were cleaned before obtaining two MSUs, contrary to the 1,335 children included in 2008-2010 ("non-cleaning period"). Significant bacteriuria was defined as at least 10,000 colony-forming units/ml of the same uropathogenic bacterium in two MSUs in monoculture. Contamination was defined as all other microbiological findings.

RESULTS

The procedure of no cleaning before sampling increased the risk of contamination in 0-9.9-year-old children from 43% to 49% (p = 0.034); and specifically in 0-9.9-year-old girls, the risk of contamination increased from 47% to 55% (p = 0.018). No significant effect was demonstrated in 10-15-year-old girls (p = 1.0) or in boys, independent of age (p = 0.19). In both periods, 31% of paired MSUs from the same child were without any bacterial or fungal growth.

CONCLUSION

Cleaning before collecting urine from girls younger than ten years of age is recommended to minimise the risk of contamination. Cleaning was without effect on children aged 10-15 years.

FUNDING

not relevant.

TRIAL REGISTRATION

not relevant.

Experience with the NICE guidelines for imaging studies in children with first pyelonephritis

PURPOSE

This retrospective study evaluates the applicability of a selective approach for imaging in children aged 0-15 years with a first episode of pyelonephritis, based on the UTI guidelines of the National Institute for Health and Clinical Excellence (NICE).

MATERIAL AND METHODS

A total of 96 consecutive patients were included (age range: 0.1-14.9 years, median age: 0.7 years), treated for a first episode of confirmed culture-positive pyelonephritis. At initial hospitalization all patients underwent ultrasound examination of the kidneys and urinary tract (US) and technetium-99m mercaptoacetyltriglycine scinti- and renography ( (99m)Tc MAG3). If vesicoureteral reflux (VUR) was suspected, then prophylactic antimicrobial therapy was prescribed and the patients were referred to a surgeon for further evaluation including voiding cystoureterography (VCU). Patients with known urological anomalies including antenatally diagnosed anomalies were excluded. All patients were followed up for a median of 5.2 years (3.5-8.6 years).

RESULTS

Initially, US findings were abnormal in 29 (30%) patients and (99m)Tc MAG3 findings were abnormal in 20 (21%) cases. At follow-up, prophylactic antimicrobial therapy was prescribed for 19 (20%), and VUR was diagnosed by VCU in 9 patients. Surgery was carried out in 7 (7%) patients, primarily for VUR. If the NICE guidelines had been initially followed, 5 of our 9 patients with VUR would not have been identified. VUR surgery was performed in 4 of these cases. Moreover, 9 cases with urological anomalies subsequently prescribed prophylactic antimicrobial therapy would have been missed.

CONCLUSION

We do not recommend following the imaging strategies of the NICE guidelines for children with a first episode of pyelonephritis. Our most important argument is that at follow-up, after a minimum of 3.5 years, the initial diagnosis of VUR would have been missed in 4 out of the 5 patients who underwent VUR surgery.