Patterns of stress hormone levels in women, even before pregnancy, can predict baby birth weight, according to a new study.
While most people wake up with high levels of cortisol that decrease throughout the day, some people wake up with low levels of cortisol that decrease by smaller amounts during the day. Previous studies have linked this cortisol pattern to chronic stress, trauma and diseases like cancer and atherosclerosis.
The latest study, which involved data from 142 women participating in the Community Child Health Network, revealed that women with low levels of cortisol were significantly more likely to give birth to lower weight babies.
"We found that the same cortisol pattern that has been linked with chronic stress is associated with delivering a baby that weighs less at birth," lead researcher Christine Guardino, of the University of California Los Angeles, said in a university release.
Researchers said the latest findings are the first to show that maternal stress hormone levels matter even before conception. Previous studies have shown that levels of stress hormones during pregnancy can seriously influence fetal growth and development.
In light of the latest findings, researchers say that women should start planning for pregnancy well before conception.
"Improving pre-conception health can profoundly improve our overall health," said co-researcher Dunkel Schetter, according to a university release. "Women should treat depression, evaluate and treat stress, be sure they are in a healthy relationship, be physically active, stop smoking and gather family support. All of the things that create an optimal pregnancy and healthy life for the mother should be done before getting pregnant."
For the study, researchers included African-American, Latino or Hispanic, and white non-Hispanic mothers. Researchers said that the majority of mothers in the study had household incomes of near or below the federal poverty level. They also reported numerous stress sources including finances, family relationships, neighborhood issues, death of a relative and interpersonal violence and racism. Researchers determined participant stress levels by measuring blood pressure, body mass index, the level of cortisol in participant saliva and other factors.
The latest findings were published in the journal Health Psychology.
