I was recently asked about how maternal stress impacts pregnancy and pregnancy outcomes. Although it is very difficult to define exactly what “stress” is, the information I discovered was indeed very interesting. Not to my surprise, was the very common finding that maternally perceived stress significantly increased the likelihood of preterm delivery. In studies by Dunkel, Schetter and Tanner 2012, and Kramer et al. in 2009, they both demonstrated that “women with high anxiety during pregnancy were 1.5 times more likely to experience preterm birth.” Significant associations were found between the levels of perceived maternal anxiety and the timing of delivery. Pregnancy related anxiety was universally associated with shorter gestation and preterm birth. They defined pregnancy related anxiety as “a syndrome in which the concerns of the mother are centered around the health and wellbeing of the baby, birth, and postpartum.” Obviously, it is good to be concerned about the wellbeing of your baby, but, these women tended to be overly focused on that one particular aspect of their lives, almost to the exclusion of everything else.

maternal stress fetal developmentSmoking, and the stress related to smoking, also had tremendously negative influences on the developing babies of women who engaged in cigarette use during pregnancy. In a study at Oxford University in the United Kingdom, researchers found that maternal smoking was associated with increased risks of adverse visual outcomes in their children. Specifically, “higher rates of strabismus, refractive errors, and retinopathy.” Maternal cigarette smoking exerts an immediate adverse effect on placental blood flow causing an immediate fetal hypoxia. This hypoxia, or decreased oxygenation of the fetus, has been associated with preterm delivery, IUGR or Intrauterine Growth Restriction, low birth weight, congenital malformations, orofacial malformations, GI, and cardiac defects to name a few. Smoking increases the risk of cognitive and behavioral problems as well, including ADD or Attention Deficit Disorder, with higher rates of anti-social behavior and drug abuse among adolescents of mothers who smoked during pregnancy.

It should come as no surprise that smoking is so detrimental to the developing fetus, but it may surprise you that both maternal over- and under-nutrition have a negative impact as well. Maternal obesity has been linked to childhood and adult obesity, hypertension, birth defects, mental illness, and increased risks of Type 2 diabetes in their offspring! On the flip side, maternal malnutrition and poor weight gain have been associated with preterm delivery, IUGR, and poor immune function. Specifically, a lack of vitamin A, zinc, vitamin E, iron, and certain fatty acids have been linked to immune function including improper antibody formation, hematopoiesis, cell mediated immunity, childhood asthma, and allergies. It has long been known that inadequate levels of folic acid increase the risk of neural tube defects and has recently been implicated in poor language skills as well.

The good news is that although all of us experience “stress” at times, there are very effective ways to deal with stress as it relates to pregnancy. One of the statements I emphasize to pregnant mothers is the idea that “a healthy mother equals a healthy baby.” There is indeed a mountain of evidence on the very beneficial effects of physical activity on the maternal-fetal unit, and how regular physical activity can create a buffer against chronic stress and related illness. Regular activity has been shown to promote fetal neuroplasticity and decrease inflammation. Being active on a regular basis helps to elevate our mood, gives us a sense of wellbeing, and makes all of us have a better outlook on life! It helps us all deal more effectively with life’s difficulties.

In addition to regular activity, an interesting article originating out of Australia (Woolhouse, Mercuri, Judd, and Brown) found that women who learned and practiced new coping skills were able to reduce their stress and had better pregnancies and were able to implement those skills in their lives after the delivery. The program was called the “MindBabyBody” mindfulness program which included both mothers with prior anxiety issues and a general population cohort. Each participant attended classes of “mindfulness” and were taught meditation, mindful walking, self compassion, and other stress coping skills. After participating in the MindBabyBody program, one participant stated that “learning to get a grasp of negative thought processes that make me angry— particularly with my partner—and not carrying through to a crisis point was really big for me.” Another mother stated that learning the coping skills in the MindBabyBody program “has pretty much changed my life. It has helped me to be far more in tune and more relaxed about being a mum.” (Yes “mum,” it was in Australia!) Although I know of no similar programs in the U.S., there are many self-help books and also psychological medical providers that can put women in touch with some of these same coping skills to help with anxiety and the stresses of pregnancy.
In summary, “a healthy mother really does equate to a healthy baby.” Expectant mothers who engage in regular physical activity, eat a healthy well balanced diet, and learn how to better control their emotions, will indeed be more capable of enjoying their pregnancy and experience the wondrous gift of life.