Heart disease: The leading cause of deaths related to pregnancy in California

Heart disease is the leading cause of women's pregnancy-related deaths in California - but nearly one-third could be prevented, according to research presented at the American Heart Association's Scientific Sessions 2013.

Maternal death rates have been increasing in California and the United States since the mid-1990s, according to statistics from the California Department of Public Health.

"Women who give birth are usually young and in good health," said Afshan B. Hameed, M.D., the study's lead researcher and associate professor of clinical cardiology, obstetrics and gynecology at the University of California, Irvine. "So heart disease shouldn't be the leading cause of pregnancy-related deaths, but it is."

She said the results likely apply to the rest of the United States.

There were 2.1 million live births in California from 2002-2005. Researchers analyzed medical records of 732 women who died from all causes while pregnant or within one year of pregnancy and found that:

• 209 deaths were pregnancy-related.
• 52 (about one quarter) of the pregnancy-related deaths were from some form of cardiovascular disease. Of note, only 6 percent had been diagnosed with a heart condition prior to the pregnancy.
• 33 (or two-thirds) of the cardiovascular-related deaths were from cardiomyopathy - a serious disease in which the heart muscle is weakened and can lead to heart failure, irregular heartbeats, heart valve problems and death. Compared to women who died of non-heart-related causes, researchers found that:
• Women who were most likely to die from pregnancy-related heart disease were African-American, obese or had documented substance abuse during pregnancy.
• Nearly one-fourth of the women who died of cardiac causes had been diagnosed with high blood pressure during their pregnancies. In about two-thirds of the deaths, the diagnosis was either incorrect or delayed, or providers had given ineffective or inappropriate treatments, researchers said. One third of the patients who died had delayed or failed to seek care, 10 percent refused medical advice and 27 percent did not recognize their symptoms as cardiovascular.

"Women should attain and maintain proper weight before and during pregnancy, and talk to their doctors if they have personal or family histories of heart disease," Hameed said. "And healthcare providers should be referring pregnant women who complain of symptoms consistent with cardiac disease to specialists, especially when these risk factors are present. Women with evidence of substance abuse should receive early referral for treatment."

But, Hameed noted, it is impossible to know if earlier diagnosis and intervention would have prevented death in these cases "as missed cues to the presence of heart disease were common."