Something very surprising could help determine the eventual birth weights of your children. Spoiler alert: it has to do with how you handle stress.
A woman's likelihood of giving birth to a lower birth weight baby is determined well before she becomes pregnant. Actually, it might just be determined by a mother's biological profile, new research suggests.
The study finds that your levels of cortisol, which is a hormone your body releases during times of stress, might play a role in determining the birth weights of your babies. Most people have high levels of cortisol when they wake up and this level decreases as the day goes on—but others have lower amounts first thing in the morning, and this level decreases very gradually throughout the day. The latter trait is associated with diseases like atherosclerosis and cancer. It's also linked to chronic stress.
Stress and baby weight
According to researchers from UCLA, who were reportedly the first to examine the link between birth weight and maternal cortisol patterns before pregnancy, people with lower levels of cortisol are likely to deliver babies with low birth weights.
"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 author Christine Guardino said. A baby is considered to have a low birth weight when she weighs under 5.5 pounds, accounting for 300,000 US births every year. Low birth weight infants have higher risk for infant mortality and health abnormalities that can persist throughout their lives, including cardiovascular and metabolic disorders.
The researchers studied women from different states, income levels and races. According to an abstract for the study, the women were affected by financial, relationship, societal, familial and neighborhood stressors. Researchers gauged stress levels by measuring blood pressure, body mass index, levels of cortisol in saliva and conducting a series of interviews. The researchers followed up with study subjects, whose children are now between three and five years old.
What you can do
So what can women do to reduce their risks of having low birth weight babies?
"Improving preconception health can profoundly improve our overall health," Chris Dunkel Schetter, the study's co-lead author said. "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."