Impact of prenatal diagnosis of transposition of the great arteries on postnatal outcome

Second trimester echocardiography

Fetal echocardiography involves a comprehensive cardiac assessment aiming to make a complete structural examination of the heart as well as to detect signs of cardiovascular adaptation to different insults. For the former, this assessment entails expert's evaluation of the anatomy of the heart including additional views beyond the five axial views used in cardiac screening examinations and always complemented with colour and pulsed Doppler. Echocardiography may accurately diagnose most congenital heart defects in fetal life, which enables adjusting the perinatal management. For the latter, echocardiography encompasses cardiac morphometric assessment to identify signs of cardiac remodeling indicative of cardiac adaptation in structure, shape, and size in response to underlying diseases, and cardiac functional assessment to detect signs of systolic and/or diastolic dysfunction. The most used parameters to study the systolic function (stroke volume, cardiac output, ejection fraction, fractional shortening, and mitral and tricuspid annular plane systolic excursion), diastolic function (characteristics of flow in the precordial veins and through the atrioventricular valves) and global myocardial function (myocardial performance index) will be discussed in this review.

The Association of Prenatal Diagnoses with Mortality and Long-Term Morbidity in Children with Specific Isolated Congenital Anomalies: A European Register-Based Cohort Study

OBJECTIVES

To compare 5-year survival rate and morbidity in children with spina bifida, transposition of great arteries (TGA), congenital diaphragmatic hernia (CDH) or gastroschisis diagnosed prenatally with those diagnosed postnatally.

METHODS

Population-based registers' data were linked to hospital and mortality databases.

RESULTS

Children whose anomaly was diagnosed prenatally (n = 1088) had a lower mean gestational age than those diagnosed postnatally (n = 1698) ranging from 8 days for CDH to 4 days for TGA. Children with CDH had the highest infant mortality rate with a significant difference (p < 0.001) between those prenatally (359/1,000 births) and postnatally (116/1,000) diagnosed. For all four anomalies, the median length of hospital stay was significantly greater in children with a prenatal diagnosis than those postnatally diagnosed. Children with prenatally diagnosed spina bifida (79% vs 60%; p = 0.002) were more likely to have surgery in the first week of life, with an indication that this also occurred in children with CDH (79% vs 69%; p = 0.06).

CONCLUSIONS

Our findings do not show improved outcomes for prenatally diagnosed infants. For conditions where prenatal diagnoses were associated with greater mortality and morbidity, the findings might be attributed to increased detection of more severe anomalies. The increased mortality and morbidity in those diagnosed prenatally may be related to the lower mean gestational age (GA) at birth, leading to insufficient surfactant for respiratory effort. This is especially important for these four groups of children as they have to undergo anaesthesia and surgery shortly after birth. Appropriate prenatal counselling about the time and mode of delivery is needed.

Preoperative Care of Neonates With Congenital Heart Disease

Congenital heart disease (CHD) is one of the most common types of birth defects, with 40,000 newborns diagnosed yearly in the United States. This article describes: (1) four common heart defects seen in neonatal intensive care units, (2) the typical medical/nursing care of these neonates, and (3) common surgical management for the defects. Hypoplastic left heart syndrome, dextro-transposition of the great arteries, tetralogy of Fallot, and pulmonary atresia with intact ventricular septum are four common types of CHD requiring NICU admission. Knowledge of these defects will help nurses to appropriately manage and treat neonates with these types of CHD.

Prenatal Diagnosis of Transposition of the Great Arteries Reduces Postnatal Mortality: A Population-Based Study

BACKGROUND

Transposition of the great arteries (TGA) may present as a life-threatening neonatal malformation. Although prenatal detection facilitates the perinatal management, the impact on outcome is controversial.

METHODS

This study reviewed the differences in prenatal diagnosis of TGA from 2009 to 2014 among the 5 geographic areas in Ontario and compared the management, morbidity, and mortality among neonates with a prenatal (prenatal cohort; n = 70) vs a postnatal (postnatal cohort; n = 76) anomaly diagnosis. Cases were identified from prospective databases of the provincial cardiac tertiary centres and the coroner's office.

RESULTS

Prenatal TGA detection rates varied significantly among areas (median: 50%; range: 14% to 72%; P = 0.03). Compared with the postnatal cohort, time from birth to tertiary care admission (1.4 vs 10.4 hours, P < 0.001), prostaglandin therapy (0.1 vs 5.3 hours; P < 0.001), balloon atrial septostomy (5.3 vs 14.9 hours; P <0.001), and arterial switch operation (6 vs 9 days, P = 0.002) was significantly shorter in the prenatal cohort. Although other preoperative variables-including the need of ventilation and mechanical support, morbidity score, and lowest pH and preductal oxygen saturations-were comparable, a prenatal diagnosis was associated with improved 1-year survival (odds ratio: 0.108; 95% confidence interval, 0.013-0.88; P = 0.0184).

CONCLUSIONS

Prenatal diagnosis of TGA significantly shortened time intervals from birth to neonatal care and surgery and was associated with improved survival. The prenatal detection rate of TGA in Ontario was low (50% or less) outside of Metropolitan Toronto, suggesting the need for new strategies to further improve intraprovincial detection rates.

Do infants with transposition of the great arteries born outside a specialist centre have different outcomes?

BACKGROUND

Infants born with undiagnosed transposition of the great arteries continue to be born in district general hospitals despite the improvements made in antenatal scanning. Evidence indicates improved outcomes with early definitive treatment after birth, hence the recommendation of delivery in a tertiary centre. The role of specialist paediatric and neonatal transport teams, to advise, stabilise, and transport the infants to a tertiary centre in a timely manner, is critical for those infants born in a district general hospital. This pilot study aims to compare outcomes between infants born in district general hospitals and those who were born in a tertiary maternity unit in South West England and South Wales.

METHODS

This was a secondary data analysis of data collected from the local Paediatric Intensive Care Audit Network and the local transport database. Infants born with a confirmed diagnosis of transposition of the great arteries, that required an arterial switch operation as the definitive procedure between April, 2012 and March 2018 were included.

RESULTS

Forty-five infants with a confirmed diagnosis of transposition of the great arteries were included. Statistical analysis demonstrated there were no significant differences in the time to balloon atrial septostomy (p = 0.095), time to arterial switch operation (p = 0.461), length of paediatric ICU stay (p = 0.353), and hospital stay (p = 0.095) or mortality between the two groups.

CONCLUSIONS

We found no significant differences in outcomes between infants delivered outside the specialist centre, who were transferred in by a specialist team.

Prenatal detection of critical cardiac outflow tract anomalies remains suboptimal despite revised obstetrical imaging guidelines

BACKGROUND

Fetal echocardiography can accurately diagnose critical congenital heart disease prenatally, but relies on referrals from abnormalities identified on routine obstetrical ultrasounds. Critical congenital heart disease that is frequently missed due to inadequate outflow tract imaging includes anomalies such as truncus arteriosus, double outlet right ventricle, transposition of the great arteries, tetralogy of Fallot, pulmonary stenosis, and aortic stenosis.

OBJECTIVE

This study evaluated the prenatal detection rate of critical outflow tract anomalies in a single urban pediatric hospital before and after "AIUM Practice Guideline for the Performance of Obstetric Ultrasound Examinations," which incorporated outflow tract imaging.

DESIGN

Infants with outflow tract anomalies who required cardiac catheterization and/or surgical procedure(s) in the first 3 months of life were retrospectively identified. This study evaluated two time periods; pre-guidelines from June 2010 to May 2013 and post-guidelines from January 2015 to June 2016. June 2013-December 2014 was excluded as a theoretical period necessary for obstetrical practices to implement the revised guidelines.

RESULTS

Overall, prenatal diagnosis occurred in 55% of infants with critical outflow tract anomalies; of the three most common defects, prenatal diagnosis occurred in 53% of D-transposition of the great arteries, 63% of tetralogy of Fallot, and 80% of double outlet right ventricle patients. Pre-guidelines, prenatal diagnosis occurred in 52% (52 of 102) infants with critical outflow tract anomalies requiring early cardiac intervention. Post-guidelines, prenatal diagnosis occurred in 61% (33 of 54) infants, not significantly different than the prenatal detection rate pre-guidelines (P = .31).

CONCLUSIONS

Despite revised obstetrical guidelines highlighting the importance of outflow tract imaging, referrals and prenatal diagnosis of these types of critical congenital heart disease remain low. Education of obstetrical sonographers and practitioners who perform fetal anatomic screening is vital to increase referrals and prenatal detection of critical outflow tract anomalies.