Pregnancy is far from a stress-free time of life. But, most mothers try their best to provide a healthy, happy placental home for nine months, knowing that anything she does to or for herself, she does to her growing fetus. The placental environment is sensitive to many foods, drinks, medications, and even activities, and the effects of many of these (think smoking and drinking) have long-term negative consequences. But, in addition to these external influences, internal factors, including psychological health and hormone levels, affect fetal development. A new study to be published in an upcoming issue of Psychological Science claims that, in fact, consistency of maternal mental health is more important in fetal outcomes than whether or not the mother is actually healthy.

The study, whose findings were published early through a press release by the Association for Psychological Science, examined how a mother’s mental state, specifically signs and symptoms of depression, influenced the development of babies, both before and after birth. Interestingly, the babies with the best developmental outcomes were those who grew in a consistent environment. That is, babies whose mothers were healthy both before and after birth and babies whose mothers were depressed both before and after birth had higher developmental scores than babies whose mothers went from healthy to depressed or depressed to healthy during or after birth.

Related studies by the same team of researchers revealed that anxiety during pregnancy, and its related fluctuations in hormones, predicts infant development and temperament. The higher the levels of cortisol, which indicate elevated levels of stress, at different points during pregnancy were significantly associated with negative reactivity and impaired adaptation to stress in infants. Maternal cortisol levels were also related to a more difficult temperament, behavioral and emotional problems, and delayed motor and cognitive development in infants. There is also evidence that cortisol levels during pregnancy result in differences in brain structures in infants.

So, what is a mom to do? Clearly, a lifetime of emotional and psychological connections to her baby begins in the womb, and unstable mental health places the child at risk for developmental, emotional, and cognitive impairment. But, so far, none of these studies have been able to prove if these connections are transient, persistent, or progressive. And, levels of stress and depression are only part of a myriad of conditions and environmental factors that influence development in offspring.

Throughout life, maternal-child interactions are dynamic and influenced by numerous internal and external factors. The current research underscores just how early these interactions start. And, it emphasizes that consistency is key. As the authors note, a cynical interpretation would be to let women who are depressed or anxious stay that way, in order to provide a consistent fetal environment. But, a more pragmatic approach would be to screen mothers-to-be before pregnancy for mental health conditions that may affect their babies later in life. And, monitoring of children at risk for psychological or developmental issues will lead to early intervention and treatment.

Maybe the bottom line is that fetuses should start preparing themselves early for a lifetime of mixed messages from mom.

References

Blair MM, Glynn LM, Sandman CA, & Davis EP (2011). Prenatal maternal anxiety and early childhood temperament. Stress (Amsterdam, Netherlands), 14 (6), 644-51 PMID: 21790468

Buitelaar JK, Huizink AC, Mulder EJ, de Medina PG, & Visser GH (2003). Prenatal stress and cognitive development and temperament in infants. Neurobiology of aging, 24 Suppl 1 PMID: 12829109

Change in mother’s mental state can influence her baby’s development before and after birth. Press release Nov. 9, 2011.

Davis EP, Glynn LM, Schetter CD, Hobel C, Chicz-Demet A, & Sandman CA (2007). Prenatal exposure to maternal depression and cortisol influences infant temperament. Journal of the American Academy of Child and Adolescent Psychiatry, 46 (6), 737-46 PMID: 17513986

Davis EP, & Sandman CA (2010). The timing of prenatal exposure to maternal cortisol and psychosocial stress is associated with human infant cognitive development. Child development, 81 (1), 131-48 PMID: 20331658

de Weerth C, van Hees Y, & Buitelaar JK (2003). Prenatal maternal cortisol levels and infant behavior during the first 5 months. Early human development, 74 (2), 139-51 PMID: 14580753

Huizink AC, Robles de Medina PG, Mulder EJ, Visser GH, & Buitelaar JK (2003). Stress during pregnancy is associated with developmental outcome in infancy. Journal of child psychology and psychiatry, and allied disciplines, 44 (6), 810-8 PMID: 12959490

Sandman CA, Davis EP, Buss C, & Glynn LM (2011). Exposure to Prenatal Psychobiological Stress Exerts Programming Influences on the Mother and Her Fetus. Neuroendocrinology PMID: 21494029

Sandman CA, Davis EP, Buss C, & Glynn LM (2011). Prenatal programming of human neurological function. International journal of peptides, 2011 PMID: 21760821