Cardiovascular risk increased in mothers of infants with heart defects

By Naveed Saleh, MD, MS, for MDLinx
Published April 9, 2018

Key Takeaways

In a recent study published in Circulation, researchers found that mothers of infants with congenital heart disease are at increased risk for cardiovascular hospitalization later in life. Risk factors for cardiovascular disease that occur early in life are poorly understood.

Nathalie Auger, MD, MSc, Institut national de santé publique du Québec, Montreal, Canada, and co-authors, analyzed the long-term risk of cardiovascular disease in mothers who gave birth to infants with congenital heart disease. They also found that heart defects in children could serve as a marker for cardiovascular disease in mothers.

“Despite supportive evidence for a link between congenital heart defects in infants and maternal cardiovascular risk, the association between the two has yet to be studied,” the authors wrote. “We therefore assessed the long-term risk of cardiovascular disease in women whose newborns had heart defects.”

The researchers gathered data that included all women who delivered one or more live births in Quebec, Canada, between 1989 and 2013 (N = 1,084,251). This cohort of mothers was followed longitudinally for up to 25 years for any cardiovascular hospitalizations (eg, heart failure, myocardial infarction, pulmonary embolism, and ischemic stroke) or interventions (eg, coronary angioplasty, coronary artery bypass grafting, insertion of a pacemaker, and valve replacement) that occurred after giving birth.

Follow-up was only ended after hospitalization secondary to a cardiovascular disorder or procedure, death, or the end of the study period.

Based on discharge summaries, all neonates were categorized as having critical, noncritical, or no heart defects. Potential confounders, including the following covariates, were considered:

  • Maternal age at first delivery
  • Parity
  • Preeclampsia
  • Comorbidities during pregnancy or subsequent admissions
  • Material (socioeconomic) deprivation
  • Time period during which the first pregnancy occurred

Of the more than 1 million mothers in the study, 1,516 had children with critical heart defects and 14,884 had children with noncritical defects. The incidence of cardiovascular hospitalization was higher among mothers who had children with heart defects.

Estimated incidence of cardiovascular hospitalizations included:

  • 38 cardiovascular hospitalizations per 1,000 person-years for critical defects
  • 19 cardiovascular hospitalizations per 1,000 person-years for noncritical defects
  • 42 cardiovascular hospitalizations per 1,000 person-years for no heart defects

Even after adjusting for confounding variables, having a child with a congenital heart defect was associated with an increased risk of maternal hospitalization for cardiovascular disease. Specifically, mothers with infants who had critical or noncritical heart defects had >25% chance of any cardiac hospitalization later in life.

Notably, mothers whose offspring had either critical or non-critical heart defects were more likely to be hospitalized earlier during follow-up for cardiovascular disease than those mothers who had offspring with no heart defects.

For example, with respect to later hospitalization with myocardial infarction, it took a median of 7.2 years to reach five hospitalizations in women who had offspring with critical heart defects. This period extended to 9.8 years in women whose children had no heart defects.

Moreover, the risk of cardiovascular hospitalization varied based on the type of heart defect. For instance, women whose infants had hypoplastic left heart syndrome were 2.24 times more likely to undergo cardiac hospitalization than those mothers whose infants had no heart defects.

The authors reported that the mechanism underlying how congenital heart defects in offspring tie to cardiovascular hospitalization in the mother has yet to be elucidated, but the role of genetics “cannot be excluded.” In addition, stressors such as anxiety or depression could play a role.

“Caring for infants with critical heart defects is associated with psychosocial and financial stress, which may increase the mothers’ long-term risk for cardiovascular disease,” Dr. Auger said.

Specifically, infants with severe heart defects can require multiple, costly hospitalizations.

“With 85% of infants with heart defects now surviving past adolescence, the psychosocial impact of congenital heart disease on caregivers may not be benign, and may have a cumulative effect over the long term,” the authors wrote.

They also suggest that the results of their study support early prevention strategies and counseling to reduce the risk of cardiovascular disease in women with offspring who have heart defects.

Furthermore, Dr. Auger said that obstetricians and other physicians “are very well-positioned to inform women about this possibility, the greater risk of heart disease, and to provide recommendations for targeting other risk factors like smoking, obesity, and physical activity.”

This research was funded by the Canadian Institutes of Health Research, Public Health Agency of Canada, and Fonds de recherché du Québec-Santé.

To learn more about this study, click here.

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