Why Women Are Experiencing More Heart Attacks During Pregnancy, According To New Research

Even though medicine has advanced immensely over the course of human existence, making pregnancy much safer than it was a few decades ago, there are still risks that come with pregnancy and childbirth. And according to a new study, the risk of heart attack during pregnancy, childbirth, and the postpartum period have steadily risen in recent years for a variety of reasons.

The study, conducted by the NYU School of Medicine and published in Mayo Clinical Proceedings on Wednesday, found that the risk of American women experiencing an acute myocardial infarction (aka a heart attack) while pregnant, giving birth, or in the two months after birth increased by 25 percent from 2002 to 2014. To conduct the study, researchers did not interact with any patients — instead, they collected and analyzed data from 55,402,290 hospitalizations in that 12-year time period. Each hospitalization occurred during pregnancy or the puerperium period (the six weeks after giving birth), all in women 18 years or older in the United States.

In total, 4,471 instances of heart attacks occurred per every 100,000 hospitalizations during pregnancy. According to the study, the researchers found that the chances of a heart attack were much higher in patients during the antepartum (pre-childbirth) period and postpartum period than during childbirth. Additionally, as the research found, 4.5 percent of women studied who had heart attacks during pregnancy or the puerperium period passed away in the hospital.

Dr. Sripal Bangalore, the study's senior investigator and an interventional cardiologist, believes that the stress of pregnancy has contributed to the rising rate of heart attacks surrounding pregnancy. In a press release of the study, Bangalore explained:

Our analysis, the largest review in a decade, serves as an important reminder of how stressful pregnancy can be on the female body and heart, causing a lot of physiological changes, and potentially unmasking risk factors that can lead to heart attack.

Another one of the study's authors, Dr. Nathaniel Smilowitz, an assistant professor at NYU Langone and an interventional cardiologist, highly encourages pregnant people to consult with their doctors early on to lessen the risk of heart disease. Smilowitz explained in the same press release:

Our findings highlight the importance to women considering pregnancy to know their risk factors for heart disease beforehand ... These patients should work out a plan with their physicians to monitor and control risk factors during pregnancy so that they can minimize their risk.

So what is the cause of the increased rate in heart attacks among women who are pregnant, giving birth, and in the postpartum period? The researchers suggested that they believe three central factors could be affecting this alarming increased risk:

1. Women Are Having Children Later In Life

According to the study's press release, the fact that women are having children later in life has increased the risk of a heart attack surrounding a pregnancy. In general, the older people get, the more likely they are to have a heart attack — especially while pregnant, the study noted. A pregnancy between the ages of 35 to 39 is five times more likely to have a heart attack than a pregnancy at the age of 20 to 29, and a pregnancy at 40 to 49 is 10 times more likely to have a heart attack than a pregnancy at 20 to 29, according to the study's press release.

Specifically, once women are 55 years old, they become more likely to have a heart attack than younger women, according to the Mayo Clinic. And according to a 2014 report published by the Centers for Disease Control and Protection (CDC), the amount of women having their first kid after age 35 has increased steadily over the past several decades, and even more so since 2000, as TIME reported.

2. There Has Been A Rise In Obesity & Diabetes

The researchers also believe increasing rates of obesity and type 2 diabetes have affected these distressing statistic. According to the State of Obesity's website, people who are obese are more likely to develop type 2 diabetes and heart disease, among other health issues. In the United States, more than than one in three adults are obese, the State of Obesity added.

3. Heart Attacks Easier To Detect Now

And finally, according to the study, heart attacks have become easier to detect thanks to modern technology. This could mean that pregnant women pre-2002 may have suffered many more heart attacks than previously thought, but these heart attacks simply went undetected and therefore unrecorded, as noted by the researchers.

In addition to the researchers' top three suspicions, there are many other common risk factors for heart attacks. According to the Mayo Clinic, these risks include: getting older, smoking tobacco, having high blood pressure, having high blood cholesterol, being inactive, stress, and having an autoimmune condition.

All that being said, plenty of medical advancements have been made in recent years that can also help women prevent and treat heart disease. If you think you are at risk for heart disease during pregnancy, make sure to discuss any concerns or questions with your doctor.