Pregnancy loss associated with increased risk of cardiovascular disease

Women who experience a termination of pregnancy and have no children are at greater risk of cardiovascular disease, such as heart disease and stroke, than women with one or two children , according to a new study from the University of Cambridge and the University of North Carolina.

The study, published today in the Women's Health Journal, also found that women with five or more children are at increased risk for cardiovascular disease later in life.

Cardiovascular disease is the leading cause of death among women in all major developed countries and most emerging economies. Around 28,000 women die each year from heart attacks in the UK. In 2016 alone, 20,000 women died as a result of a stroke, a higher number than in men.

During pregnancy, the mother's body undergoes changes during pregnancy, including weight gain and abdominal fat accumulation, higher cholesterol levels, increased insulin resistance, and changes in body fat. the structure of the heart. Although most of the changes occurring during pregnancy are temporary, these changes are known to be risk factors for cardiovascular disease in the general population.

Previous studies had attempted to evaluate the link between pregnancy and childbirth and cardiovascular disease. However, because of the limitations of these studies – including not taking into account badfeeding history and grouping women who have never been pregnant with those who were pregnant but who lost pregnancy – their results have been inconclusive and sometimes contradictory.

In this new study, a team of American and British researchers badyzed data from more than 8,500 white and African-American women aged 45 to 64 in the United States. This included health services data on cardiovascular disease over a 30-year period (1987-2016) and self-reported data on the number of pregnancies and births and badfeeding practices.

In the study population, 138 women reported experiencing a pregnancy loss and no live births. 3,108 women had one or two live births, 3,126 had 3-4 live births, and 1,694 had five or more live births.

The researchers found that women who had lost their pregnancy and did not have children born alive had a 64% higher risk of coronary heart disease and a 46% risk of heart failure. higher than women with one or two children. Women with five or more births were 38% more likely to have a serious heart attack, regardless of the duration of badfeeding.

The team says that there may be several possible reasons for the link between cardiovascular risk and multiple births. Repeated pregnancies can lead to lasting changes in the body, including weight gain, especially around the waist, and increased cholesterol levels in the blood. In addition, the number of children that a woman has taken into account also includes other factors, including children 's education, age at menopause, and problems with pregnancy. health. Therefore, researchers say that it is unclear whether the increased risk of heart failure, coronary heart disease and heart attacks reflects the direct impact of repeated pregnancies, or the badociated stressors to the education of several children, or both.

The increased risk of coronary heart disease and heart failure seen in women who have ever had a pregnancy, but without a live birth, may reflect the increased risk previously identified after a history of miscarriage. Several mechanisms have been proposed to underlie the relationship between miscarriage and coronary artery disease, including immune disorders, chronic disease, and endothelial dysfunction (cells lining the interior of blood vessels). .

"Diseases such as heart disease and stroke are the leading cause of death among women in developed countries and it is essential that we understand why," says Dr. Clare Oliver-Williams, a junior researcher at Homerton College. works in the Department of Public Health and Primary Care of the University of Cambridge. "Our work suggests that there is a relationship between the risk of cardiovascular disease and both the loss of pregnancy and the high number of deliveries.

"This study is not designed to stress and worry women, especially those who have experienced the distress of losing their pregnancy, but we want to give women the knowledge they need to help them reduce their risk.

"Most women know, at age 40, the number of children and the loss of pregnancy that they have suffered, years before most heart attacks and strokes occur. offers an opportunity to change their lifestyle, such as exercise and diet the risk of cardiovascular disease ".

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The research was funded by the National Heart, Lung and Blood Institute, the National Institutes of Health, the US Department of Health and Human Services and the British Heart Foundation and Homerton College. from the University of Cambridge in the United Kingdom.

Reference

Oliver-Williams, C, et al. Association between Parity and Subsequent Cardiovascular Disease in Women: ARIC Study (Risk for Atherosclerosis in Communities). the Women's Health Journal; November 27, 2018; DOI: 10.1089 / jwh.2018.7161

Researcher Profile: Dr. Clare Oliver-Williams

Ms. Clare Oliver-Williams first came to Cambridge in 2002 to study Natural Sciences as an "undergraduate student" and never completely left her, as she puts it so well. She studied her PhD here and is now a junior researcher at Homerton College.

Clare took a break from her career to start a family, but said she received "excellent support that made return to school possible and enjoyable". She now spends her time between her university or the Department of Public Health and Primary Care, although her research involves collaborating with researchers from around the world, including the United States and Europe, which has allowed her to travel Denmark and North Carolina.

"Cambridge is a great place to work for many reasons," she says. "It is a hub of knowledge and activity that brings together people from around the world, and the enthusiasm that so many researchers inspire for their work is infectious – it can be an inspiring conversation in which you hear about work and Other people's pbadions of conversation are very far from your own interests, you will feel energized and motivated. "

Clare's research is based on her doctorate, which focused on the link between miscarriages and the development of heart disease in women. She is now trying to understand the relationship between a range of feminine characteristics, such as menopause and pregnancy, and the risk of cardiovascular disease.

"Cardiovascular disease is often considered a predominantly male disease, but it also affects a large number of women," she said. "Women live unique experiences in their reproductive lives that can affect their risk of cardiovascular disease, and I want to deepen our understanding of what these experiences are and what they mean for women's long-term health."

Clare says she's already had her own "little quarter of glory time" at a conference of the British Cardiovascular Society, where her work has garnered surprising attention from the media, in particular being interviewed on the radio, recorded for a podcast and submitted to many email requests. It also helped to get noticed by the other conference participants.

"To top it off, I ended up winning a prize at the hackathon, an event dedicated to finding solutions to clinical problems.As the announcement of the winners was late, my teammate and I had finished with my kids accepted the prize on stage! "