Researchers discover surprising link between chronic stress, preterm birth
July 16, 2015
Science Daily/University of Alberta Faculty of Medicine & Dentistry
New study shows adverse life events in childhood can heighten a woman's risk of preterm birth.
Excessive stress can result in preterm birth, which has been show to affect a person's health throughout their life, surprising new research shows. The World Health Organization estimates 15 million babies are born preterm each year. It is the leading cause of death for children under the age of five, and babies who survive are at much higher risk of developing a number of health conditions including chronic lung disease, cardiovascular disease and metabolic diseases such as Type 2 diabetes.
"Chronic stress is one of the better predictors of preterm birth," says Olson, a professor of obstetrics and gynecology in the University of Alberta's Faculty of Medicine & Dentistry. "In fact, if women are exposed to two or more adverse childhood experiences while growing up, their risk of preterm birth doubles."
Olson, along with Kathleen Hegadoren, a professor in the U of A's Faculty of Nursing, and graduate student Inge Christiaens, are the authors of a new study in the journal BMC Medicine linking chronic stress with preterm birth.
The World Health Organization estimates 15 million babies are born preterm each year. It is the leading cause of death for children under the age of five, and babies who survive are at much higher risk of developing a number of health conditions including chronic lung disease, cardiovascular disease and metabolic diseases such as Type 2 diabetes. They are also at increased risk for both cognitive and behavioural issues.
As part of the study, the researchers recruited more than 200 women who had given birth in Edmonton-area hospitals. One-third of the women had given birth preterm, with the remaining women having delivered at term. The women were asked to fill out a stress questionnaire, giving researchers insight into their early life experiences and the stresses that resulted from those experiences.
"All of the adverse childhood events that we asked about had to occur prior to the age of 18, and the average age of delivery in our study was 28 years. These adverse childhood events occurred, on average, 10 years or more before the women actually delivered," says Olson.
"Although not inevitable, childhood adversity can result in long-term impacts on health across the lifespan, including pregnancy outcomes," adds Hegadoren. "Prenatal care providers need to ask pregnant women about past and current experiences that may have affected their health. In doing that, they can help women understand a potential link between life experiences and preterm birth risk."
Though the research gives important new understanding about preterm birth, more answers are still needed. The researchers are now exploring how the body can "remember" traumatic events early in life in such a way that it affects health outcomes years later. Olson believes that a high burden of stressful experiences in childhood may cause changes in how genes are expressed in later life. He notes that earlier published studies involving preclinical models suggest that may be the case but that further human studies are needed.
Olson and Hegadoren hope to continue building upon the research to better predict which women will be at risk of preterm birth. They also hope to develop early interventions.
"If we know who is at risk, we can begin to treat them before the end of their pregnancy--and hopefully they'll have improved pregnancy outcomes."
http://www.sciencedaily.com/releases/2015/07/150716101515.htm
Pregnant women with PTSD more likely to give birth prematurely
- November 6, 2014
Science Daily/Stanford University Medical Center
Pregnant women with post-traumatic stress disorder are at increased risk of giving birth prematurely, a new study has found. The study, which examined more than 16,000 births to female veterans, is the largest ever to evaluate connections between PTSD and preterm birth.
Having PTSD in the year before delivery increased a woman's risk of spontaneous premature delivery by 35 percent, the research showed. The results will be published online Nov. 6 in Obstetrics & Gynecology.
"This study gives us a convincing epidemiological basis to say that, yes, PTSD is a risk factor for preterm delivery," said the study's senior author, Ciaran Phibbs, PhD, associate professor of pediatrics and an investigator at the March of Dimes Prematurity Research Center at Stanford University. "Mothers with PTSD should be treated as having high-risk pregnancies."
Spontaneous preterm births, in which the mother goes into labor and delivers more than three weeks early, account for about six deliveries per 100 in the general population. This means that the risk imposed by PTSD translates into a total of about two additional premature babies for every 100 births. In total, about 12 babies per 100 arrive prematurely; some are born early because of medical problems for the mother or baby, rather than because of spontaneous labor.
The effect of stress
In other words, although pregnant women with PTSD may have other health problems or behave in risky ways, it's the PTSD that counts for triggering labor early.
"The mechanism is biologic," Phibbs said. "Stress is setting off biologic pathways that are inducing preterm labor. It's not the other psychiatric conditions or risky behaviors that are driving it."
However, if a woman had been diagnosed with PTSD in the past but had not experienced the disorder in the year before giving birth, her risk of delivering early was no higher than it was for women without PTSD. "This makes us hopeful that if you treat a mom who has active PTSD early in her pregnancy, her stress level could be reduced, and the risk of giving birth prematurely might go down," said Phibbs, adding that the idea needs to be tested.
Although PTSD is more common in military veterans than the general population, a fairly substantial number of civilian women also experience PTSD, Phibbs noted. "It's not unique to the VA or to combat," he said, noting that half of the women in the study who had PTSD had never been deployed to a combat zone. "This is relevant to all of obstetrics."
The VA has already incorporated the study's findings into care for pregnant women by instructing each VA medical center to treat pregnancies among women with recent PTSD as high-risk. And Phibbs' team is now investigating whether PTSD may also contribute to the risk of the mother or baby being diagnosed with a condition that causes doctors to recommend early delivery for health reasons.
http://www.sciencedaily.com/releases/2014/11/141106173639.htm