Adverse Fetal Environment Is a Cardiovascular Risk Factor

Carla Nieto Martínez

August 18, 2023

MADRID — Fetal exposure to poorly controlled diabetes or other situations that overtax the heart, or to intrauterine growth restriction, is associated with increased cardiovascular risk, according to the most recent evidence. Even though a baby may be healthy at birth, if it has been exposed to these circumstances during the pregnancy, this information must be made available, and the child must be provided with appropriate follow-up, according to researchers.

This topic was addressed at a round table discussion held during the 69th Conference of the Spanish Association of Pediatrics. The discussion touched on key advances in the field of pediatric cardiology.

Lucía Deiros, MD, PhD, is the coordinator of the Fetal Cardiology Unit of the Children's Cardiology Department at the La Paz University Hospital in Madrid. "Based on the latest evidence, we can now discuss a new cardiovascular risk factor — certain environments during fetal development — that some children will have to live with from birth," she said. "We know that the risk of developing cardiovascular disease is a sum of...the risk during the prenatal period, during childhood, and during adulthood. In this context, we can now take the fetal environment into consideration as a cardiovascular risk factor."

Deiros told Medscape Spanish Edition that this "new role" of the fetal environment as a cardiovascular risk factor is supported by multiple reviews and articles published in the past 5 years and is based on the fetal programming hypothesis. According to this hypothesis, an unfavorable intrauterine environment may affect the structure and development of cardiac function. "As a result, we consider the fetus to be a patient whose cardiac function is essential for their well-being and is linked to their future cardiovascular health."

Intrauterine Growth Restriction

Certain characteristics define an adverse fetal environment. Deiros noted that the epigenetic changes brought on in this setting that could affect fetal cardiac well-being could involve maternal disorders such as poorly controlled diabetes or conditions with more complex hemodynamics, as in twin-to-twin transfusion syndrome, which can occur in twin pregnancies.

"However, intrauterine growth restriction has been studied the most and is most closely linked with the development of cardiovascular risk in the future that is higher in comparison to the risk experienced by the child's peers. Evidence suggests that fetuses with this history may have an increased likelihood of developing cardiovascular disease, both in childhood and adulthood.

"So, for example, in childhood, defects in diastolic function, in cardiac structure, or in cardiac function may develop, whereas in adulthood, this factor has been liked to hypertension, glucose intolerance, obesity, and even heart disease or greater susceptibility to ischemia or infarction," added Deiros.

She noted that it is particularly important to be aware of this, "because knowing which of these children are exposed to a greater cardiovascular risk allows us to take action both in childhood and adulthood. Our aim is to reduce the chances of them experiencing a cardiovascular event. We're studying and treating adverse environments for the fetal heart better and better all the time. These same environments may lead to the development of cardiovascular disease in the future, so this represents a unique opportunity for prevention. This is fundamental."

On the other hand, of every 1000 live births, 6 to 12 infants enter the world with heart anomalies. Heart defects are responsible for up to 50% of defect-induced, severe morbidity in newborns. "We need to keep in mind that heart disease has multiple causes. It's estimated that the fetus in 1 of every 100 pregnancies may develop heart disease of greater or lesser severity," said Deiros.

Prenatal Diagnosis

The physician pointed out that from these case studies, the benefits of implementing prenatal diagnosis can be fully appreciated. In recent years, prenatal diagnosis has revolutionized the detection and hemodynamic management of patients with heart disease.

"Thanks to the advanced imaging technology available to us and to the greater involvement of fetal cardiologists and the expansion of multidisciplinary units, diagnostic accuracy is upwards of 90%," said Deiros. She emphasized that in addition to improved diagnosis, these advances also allow parents to be informed (if they so desire) of genetic abnormalities.

"All this has made it possible for us to predict hemodynamic management of the specific heart condition and thus reduce morbidity. It also allows us to reduce preoperative and perioperative mortality in certain heart conditions like complete transposition of the great arteries or hypoplastic left heart syndrome," she added.

Likewise, Deiros emphasized that some changes and adjustments are needed to adapt treatment guidelines for pediatric cardiologists to this new scenario. "For example, these professionals must receive appropriate training in the field of fetal cardiology, both in diagnosis and management, so that they can determine whether treatment for the heart condition must be provided during the fetal stage. They always need to be able to predict hemodynamic management, since this is a strong point of diagnosing these diseases during the prenatal stage.

"They also need to be able to work as a team," Deiros continued. "In this regard, an approach using multidisciplinary teams has led to major advances in recent years. It has enabled better management of fetuses with heart conditions, providing parents with information about their options during pregnancy in these cases, and has made it possible to anticipate the hemodynamic instability that the child will suffer when he or she is born. Multidisciplinary teams are essential for making these recommendations."

Tailored Interventions

To illustrate what this approach involves, the expert posed the scenario of children who are born with transposition of the great arteries that requires specialized cardiac management and measures such as scheduling delivery at a tertiary hospital to ensure that a cardiologist, an on-call hemodynamic specialist, and a cardiac surgeon are present.

"This is important, because in the current healthcare system, tertiary hospitals aren't everywhere. So, if that pregnancy has been diagnosed appropriately, it must be referred to a tertiary center," added Deiros.

She also noted as significant advances the establishment of the fetal cardiac ultrasound teams of today, and especially the level of medical education, both for obstetricians and pediatric cardiologists.

"Another determining factor has been the emergence of fetal cardiology guidelines that indicate the specific plans that must be made when screening the low-risk population and in the secondary screening performed when there is already a defect in the heart of the fetus, or when a potential defect has been identified," said Deiros. Thanks to these advances, an understanding has been developed of the cases in which fetal heart disease can be treated in the intrauterine stage. "We have precise indications where fetal morbidity and mortality can never outweigh the morbidity and mortality of postnatal therapy."

The significant developments that this sector has experienced have also posed multiple challenges for pediatric cardiologists. "First, we need a better understanding of the fine mechanisms of the cardiac pathophysiological response to adverse environments, and we need to understand why the fetal heart reacts in this way to hypoxia, and how it can be avoided," said Deiros.

"And we also need increasingly accurate cardiac ultrasound predictors of fetal compromise so that we know which patients, in childhood and adulthood, will need us to perform more rigorous prevention and more thorough cardiological follow-up," Deiros concluded.

Deiros has disclosed no relevant financial relationships.

Follow Carla Nieto of Medscape Spanish Edition on Twitter @carlanmartinez.

This article was translated from the Medscape Spanish Edition.


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