Small female babies and women who endure stressful pregnancies could both become more susceptible to heart, kidney, adrenal and metabolic issues after they give birth, according to the results of a new Australian study conducted on rats.
University of Melbourne research, published in The Journal of Physiology this week, finds that low birth weight and psychological stress during pregnancy are two major factors that cause women to develop health issues post-partum.
The study’s lead investigator and Professor of Physiology at University of Melbourne, Mary Wlodek, explains that women only need to fit into one of the two categories to be at risk of developing health issues after pregnancy ends.
“These two factors increase your risk or susceptibility to develop these diseases,” says Professor Wlodek.
“Women who have stressful pregnancies, resulting from a serious event or natural disaster or even chronic daily life stress, could develop diseases later in life.
“We also know that females who are born small and then, years later, get pregnant could develop health complications they wouldn’t have gotten had they been born larger.
“These two factors increase your risk or susceptibility to develop these diseases.”
Low-birth weight is defined as being under 2.5 kilograms at full-term: “this effects 10 per cent of the population so it’s a significant impact”.
“These are increases in susceptibility to diseases which affects all individuals.
“Who will develop a disease is not known but it is known that other lifestyle factors such as diet or lack of exercise can also increase your risk.”
Previous research has focused on how pregnancy affects the health of a baby. However, little is currently known about how giving birth impacts the mother’s health after pregnancy.
This is why researchers focused on maternal health post-partum. They used a rat model where restricting oxygen, nutrient and blood supply during pregnancy led to offspring being born with a low birth weight.
When the low birth weight female rats became pregnant, researchers induced stress through common measurements performed during human pregnancy.
After the pregnancy concluded, the researchers studied markers in the mothers including blood pressure, renal function, stress hormone production and metabolic function.
The researchers found that found that stress and low birth weight can independently induce cardiovascular, kidney, adrenal and metabolic health issues long after a woman’s pregnancy.
However, the study showed that having both risk factors did not lead to more severe health outcomes.
“By identifying individuals at higher risk of developing health complications after pregnancy, appropriate interventions can be implemented to improve outcomes."
Professor Wlodek notes that the research is the first of its kind and does not define how much a woman’s risk of disease will increase if they are born small or endure a stressful pregnancy.
“Rather, the risk of multiple disease – cardiovascular and metabolic – is increased above normal so that the disease emerges [in the evidence] for the first time. Thus it is physiologically and pathologically relevant.”
More research is needed to translate the results of the study, based on rats, to a human population.
Professor Wlodek also states that to-date, scientists have not defined when these women will face a heightened risk of adrenal, metabolic and cardio-renal issues disease or the specific rate of risk as no one has studied what happens to women in the long-term, after pregnancy ends.
However, she recommends that women take steps to find out how much they weighed at birth and determine if they fall into the at-risk group. Females are also advised to talk to their doctors to determine a plan to manage stress before, during and after pregnancy.
“By identifying individuals at higher risk of developing health complications after pregnancy, appropriate interventions can be implemented to improve outcomes,” says Professor Wlodek.
The team at University of Melbourne are currently conducting further research to determine a range of interventions to reduce the risk of women developing diseases as a result of stressful pregnancies. Professor Wlodek expects that the study should be completed by the early 2017.