Prenatal diagnosis of critical isolated congenital heart disease: dismantling silos to provide better care.

The prenatal obstetric ultrasound community has moved substantially towards recognition of the benefits of a prenatal diagnosis since the unfortunate impact of the underpowered RADIUS study that showed no benefit of prenatal ultrasound1. Prenatal diagnosis of critical isolated congenital heart disease (CHD) confers benefit by reducing neonatal morbidity and mortality, particularly in cases with transposition of the great arteries2,3. However, it has been difficult to show clear economic benefit in this population overall, as a prenatal diagnosis of CHD often detects the more severe cases, or those complicated by extracardiac malformations and aneuploidy, compared with liveborn infants without a diagnosis who may be ‘natural survivors’4. Even if CHD is isolated, a prenatal diagnosis results often in longer preoperative hospital stay and sometimes in increased rates of operative delivery, which add to the cost of care. The meta-analysis published in this issue of the Journal5 focuses attention on an important component of prenatal diagnosis that is usually missing from economic calculations and postnatal surgical outcome series: it evaluates whether prenatal diagnosis protects infants from dying before they can receive cardiac intervention. In this report, the authors stratified cases for similar cardiac morphology and included only those considered to be at standard risk, with no important chromosomal defects or extracardiac malformations. Their inclusion criteria were met by only eight studies, comprising outcomes from only 1373 babies, 297 of whom had a prenatal diagnosis. Demonstrating differences in outcome is difficult with a small sample but, in this study, similar to population-based studies, it is the fetus with complete transposition of the great arteries that stands to benefit most from a prenatal diagnosis and properly executed perinatal plan. Presurgical demise is recognized to occur in those babies born remote from the surgical center who require expert stabilization before transportation. Is it surprising, given the 30 years of prenatal cardiac diagnosis, that only eight studies met the criteria for inclusion in this meta-analysis? The lack of suitable studies suggests that preand postnatal care is still delivered by health professionals working in silos, with those performing pregnancy screening being remote from those caring for the newborn with CHD. Separate practice is widespread, although collaboration has been improving in Europe, where fetal cardiologists often work within the maternofetal medicine setting. In the USA, colocation and integrated practice between obstetric screening, maternofetal medicine and perinatal cardiology and surgery remain rare. Separate practice prevents easy access to outcomes and leads to poor feedback to the primary screeners, thus reducing educational opportunities. This meta-analysis may encourage the implementation of two improvement processes: first, the development of networks between maternity units and the specialist cardiac center, to improve care of the neonate with CHD, and second, the linking of maternal and newborn records, to enable tracking of outcome. Suboptimal skill levels of health professionals, outside major cardiac centers, in the perinatal recognition and management of babies with CHD puts babies born without a prenatal diagnosis, or those with a prenatal diagnosis but delivering unexpectedly, at increased risk of severe morbidity or mortality4. As many as 75% of standard-risk babies with a prenatal diagnosis of CHD could deliver safely in their local maternity unit, provided there was an effective network of care in place. The network should include regular training of local neonatal teams and community health professionals by intensivists and cardiologists from the cardiac center in the recognition and appropriate management of babies born with CHD. The second improvement process, linking maternal and newborn records, could provide information on rates of prenatal diagnosis for different types of CHD at a granular level, and enable feedback to ultrasound screeners, leading to improved competence in prenatal screening and diagnostic accuracy by identifying deficiencies and providing appropriate sonographic training6. Here, effective processes are paramount, and will differ from country to country. Unique maternal identifiers could be included in the infant electronic record to link a baby to a mother and allow access to her obstetric screening data. For those born without a prenatal diagnosis, this would allow reverse-tracking of babies undergoing cardiac surgery or interventional catheter procedures in infancy, back to the primary screeners, to help understand where deficiencies lie. This would allow targeted education to improve the prenatal detection of CHD. The information gathered on babies with and without a prenatal diagnosis would enable large epidemiological studies with sufficient power to gather population-based outcome data as well as informing training needs on a more granular level. Such a process of linking records would not be simple and, if performed clumsily, might result in unwanted societal implications,