Canadian researchers found that soon-to-be-mothers with preeclampsia, which is a pregnancy-related complication characterized by high blood pressure, may be at risk of having babies with newborn heart defects.

In a large-based population study, preeclampsia was notably linked with noncritical newborn heart defects. However, critical heart defects were associated with preeclampsia that occurred before the 34th week of gestation. The authors, nonetheless, said that the definitive risk was low.

The researchers analyzed the medical records of about two million live births before discharge in the entire province of Quebec between 1989 and 2012.

The findings of the study showed that nearly 73,000 mothers had preeclampsia. Infants born to these mothers were found to be having greater prevalence of developing "critical" heart defects, with just above 0.1 percent compared to the 0.07 percent exhibited by infants whose mothers were not preeclamptic. Particularly, the elevated risk was limited to those who had preeclampsia before the 34th week of pregnancy.

Preeclampsia was associated with mild heart defects regardless of the time of pregnancy when the condition appeared. The authors noted that 1.5 percent and 0.8 percent of newborns with preeclamptic and non-preeclamptic mothers had noncritical heart defects respectively.

After coming up with the study results, the researchers emphasized that the risk still significantly low. The report was also not able to prove that preeclampsia is the actual cause of heart defects but it suggested that congenital heart problems and preeclampsia may have similar biologic etiologies.

"That's why this study is important," said Dr. Siobhan Dolan, medical advisor to the nonprofit March of Dimes and a professor of clinical obstetrics and gynecology at Montefiore Medical Center.

The study lead author Dr. Nathalie Auger from the University of Montreal agreed with Dolan, saying that the ultimate goal is to prevent both heart problems and preeclampsia.

Auger said that their research is the first to identify a link between heart defects and preeclampsia. Now, it is hoped that this will instigate more investigations to find out the underlying reasons involved in the association, as well as determine ways on how to reduce the risks.

The study was published in the Journal of the American Medical Association on Tuesday, Oct. 20.

Photo: Torsten Mangner | Flickr

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