Post-traumatic stress disorder (PTSD) can develop after experiencing events that create fear, helplessness or horror, such as a threat to life or physical integrity. Seeing another person in a life-threatening situation can also trigger PTSD.
An estimated 7.8 percent of Americans will experience PTSD at some point in their lives, with women (10.4%) twice as likely as men (5%) to develop PTSD.
Dr. Ciaran Phibbs, PhD, associate professor of pediatrics and an investigator at the March of Dimes Prematurity Research Center at Stanford University and senior author of this study along with colleagues examined he association between antenatal post-traumatic stress disorder (PTSD) and spontaneous preterm delivery.
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.
For the study the research team identified l PTSD status and spontaneous preterm delivery in a retrospective cohort of 16,334 deliveries covered by the Veterans Health Administration from 2000 to 2012. The team then divided mothers into two groups; those diagnosed with PTSD the year before delivery (active PTSD) and those only with earlier diagnoses (historical PTSD).
The results showed of the 16,334 births, 3,049 (19%) were to mothers with PTSD diagnoses, of whom 1,921 (12%) had active PTSD. Spontaneous preterm delivery was higher in those with active PTSD (9.2%, n=176) than those with historical (8.0%, n=90) or no PTSD (7.4%, n=982) before adjustment.
Having PTSD in the year before delivery increased a woman’s risk of spontaneous premature delivery by 35 percent The association between PTSD and preterm birth persisted, when adjusting for confounders including age, race, military deployment, twins, hypertension, substance use, depression, and results of military sexual trauma screening.
According to Dr. Phibbs, “Spontaneous preterm labor has been an intractable problem.” He noted that rates of spontaneous early labor have barely budged in the last 50 years. “Before we can come up with ways to prevent it, we need to have a better understanding of what the causes are. This is one piece of the puzzle.”
Doctors want to prevent prematurity because of its serious consequences. Premature babies often need long hospitalizations after birth. They are more likely than full-term babies to die in infancy. Many of those who survive face lasting developmental delays or long-term impairments to their eyesight, hearing, breathing or digestive function.
“The mechanism is biologic,” Dr. 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 Dr. Phibbs. He adds 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, Dr. 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.
Dr. Phibbs and his team are now examining 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.
