The prevalence of stressful life events decreased slightly for women in the year preceding their infant’s birth during 2000 to 2010, according to a report from the Centers for Disease Control and Prevention.

In 2010, slightly more than 70% of women reported at least one stressful life event (SLE) in the year before giving birth. The self-reported prevalence of SLEs, however, had a statistically significant decrease over the decade, the CDC investigators wrote, with the prevalence of at least one SLE falling 0.54 percentage points per year from 2000 to 2010.

In 2010, the biggest cause of stress was financial, with 51% of women reporting at least one financial SLE. Just under 30% reported at least one emotional SLE, 28.5% reported at least one partner-related SLE (such as divorce or separation), and just under 18% reported at least one traumatic SLE. The average number of SLEs was 1.81 in 2010.

“Current research suggests that increased prenatal stress is associated with adverse pregnancy outcomes, including low birth weight, preterm birth, and peripartum depression,” the investigators wrote. “However, there is evidence that social support has a mitigating effect on the relationship between stress and adverse pregnancy outcomes.”

Find the full report in the CDC’s Morbidity and Mortality Weekly Report (2015 March 13;64:247-51).