The impact of a pregnant mother's stress on an unborn baby is debatable. Some experts believe that prolonged bouts of severe stress (like a death in the family, losing a job, etc.) can negatively impact a pregnancy, causing complications like preterm birth, low birth weight, and even sleep and behavioral disorders in young children. But will a rough deadline or two at the office, or the occasional spat with your mom or sister, pose these same risks? Probably not.
Some studies have shown that the effects of chronic stress on a fetus are minimal, and that an expectant mom tends to suffer much more than her baby does. (Chronic stress can cause a number of physical symptoms like sleep problems, digestive issues, headaches, muscle tension, and high blood pressure, for example.) The important thing to remember is that we all experience stress, and when you're pregnant it's natural that every emotion can be heightened (thanks to those crazy hormones), including the negative ones. Still, enhanced stress could come with some negative side effects, and it’s best to be prepared.
A 2015 study published in Endocrinology found that stress in the first trimester can actually affect the microbes that reside in an expectant mother's vagina. These microbes are transferred to the newborn during vaginal birth, resulting in changes to the little one's gut microbiome and brain development. In turn, the affected microbes impact the infant's immune system and metabolism. Scientists believe that the altered gut microbiota is linked to a greater risk of neurodevelopmental disorders, including autism and schizophrenia.
These effects were observed in a University of Pennsylvania lab in pregnant mice who had to endure such stressors as unfamiliar noises, predator odors, and being restrained. This all occurred during early gestation, or what might be considered the first trimester. "These results would suggest that stress might exert an effect on her offspring's development well before the woman discovers she is pregnant," postdoctoral researcher and study author Eldin JaÅ¡arevi says. "Our findings in our mouse model are consistent with epidemiological studies indicating that the first trimester is a dynamic and critical period to a variety of environmental factors—stress, infection, and malnutrition—that have been associated with an increased risk for neurodevelopmental disorders, such as autism, schizophrenia, and ADHD."
Some of the team's previous work also looked at stress during mid and late pregnancy, but they didn't find these periods to be as vulnerable.
According to research published in the journal Early Human Development, women who are anxious or depressed during pregnancy are nearly 40 percent more likely to have babies who develop sleep problems than women who aren't. The likely link: The stress hormone cortisol, which floods the body when you feel excess stress.
"This chemical can cross the placenta, affecting the part of the brain that regulates a child's sleep-wake cycles," says study author Thomas O'Connor, PhD, an associate professor of psychiatry at the University of Rochester Medical Center. "We know that child sleep is often an important measure of healthy development, so it's crucial that women pay attention to high stress levels, which can ultimately trigger chronic anxiety and depression."
Sometimes it helps to talk to another pregnant woman or mother, who can put any pregnancy or parenting issues into perspective. Or jot down thoughts that are keeping you up at night; sometimes getting them down on paper can make you take a more proactive approach to solving problems. You may also want to consider giving prenatal yoga a go; it's not only relaxing, but a great way to stay fit and healthy. The important thing is to find something that works for you – even if it's as simple as closing your eyes and taking a few deep breaths or taking a quick walk at lunch to clear your mind.
Since every woman experiences stress differently (and what drives you to the edge may be no big deal for someone else, and vice versa), it's important to know yourself and your limits. If you start to experience symptoms you can't shake (like feeling worried all the time, losing interest in your life, feeling hopeless, sleeping or eating more or less than usual, or having difficulty concentrating) you should let your doctor know. These could be signs of depression or an anxiety disorder. These conditions that affect more than 10 percent of pregnant women, and should be addressed and treated right away.