A new study determines that the interplay of feedback from a mother to her soon-to-be-delivered baby includes chemical signals conveyed through the placenta.
Researchers believe this connection allows communication of the mother’s mental status — a factor that can affect the baby after it’s born. As such, the new investigation reviews the potential impact on a newborn if their mother is or has been depressed.
Over the past half century, researchers have determined that the environment a fetus is growing up in the mother’s womb is very important. Smoking and drinking are obvious examples of detrimental consequences to the newborn.
Moreover, the fetal environment may also have a subtle impact, as studies have found that people who were born during the Dutch famine of 1944 — most of whom had starving mothers — were likely to have health problems such as obesity and diabetes later.
In the new study, Curt A. Sandman, Elysia P. Davis, and Laura M. Glynn of the University of California-Irvine investigated how the mother’s psychological state affects a developing fetus.
Pregnant women were recruited for the investigation and were assessed for depression before and after they gave birth. Then the researchers studied the newborn babies to see how well they were developing.
They found something interesting: what mattered to the babies was if the environment was consistent before and after birth.
The babies who did best were those who either had mothers who were healthy both before and after birth, and those whose mothers were depressed before birth and stayed depressed afterward.
What slowed the babies’ development was changing conditions — a mother who went from depressed before birth to healthy after or healthy before birth to depressed after.
“Now, the cynical interpretation of our results would be that if a mother is depressed before birth, you should leave her that way for the well-being of the infant. A more reasonable approach would be to treat women who present with prenatal depression,” Sandman says. “We know how to deal with depression.”
The problem is, women are rarely screened for depression before birth.
In the long term, having a depressed mother could lead to neurological problems and psychiatric disorders, Sandman says.
In another study, his team found that older children whose mothers were anxious during pregnancy, which often is comorbid with depression, have differences in certain brain structures. It will take studies lasting decades to figure out exactly what having a depressed mother means to a child’s long-term health.
“We believe that the human fetus is an active participant in its own development and is collecting information for life after birth,” Sandman says. “It’s preparing for life based on messages the mom is providing.”
The study is published in the journal Psychological Science.