Pregnant? Have a seat. Put your feet up. Take a few deep breaths and get your mind off your troubles. If you’re feeling relaxed, you’ve just done something great for your baby. According to recent scientific studies, pregnant women should avoid or at least learn how to manage stress.
How stress causes harm> A growing body of research has linked significant stress—both chronic (such as poverty or lack of social support) and the sudden, acute variety (a car accident, separation from spouse, loss of a job)—to premature birth, low birth weight and problems with fetal development, according to Pathik D. Wadhwa, M.D., Ph.D., assistant professor of psychiatry and human behavior and obstetrics and gynecology at the University of California, Irvine, College of Medicine. Even extreme anxiety related to pregnancy itself can contribute to premature labor.
A case in point is Rosie Lora, a social worker in Arizona. When she became pregnant at 22, Lora was caring for her dying mother and struggling in an abusive marriage without much money. “I was beyond stressed out,” she says. In her seventh month, her blood pressure was dangerously high and she went into premature labor. Her son was born weighing only 3 pounds, 5 ounces. To survive, he needed oxygen, intravenous feedings and a two-month hospital stay.
“The doctor said it was because of all the pressures at home,” says Lora—who, since her mother’s death, has divorced, remarried and worked her way to financial stability. Today her son is a thriving elementary-school student, though Lora still wishes her pregnancy had been healthier.
Lora’s story shows just how dangerous stress can be. “Stress plays a key role in early labor and low birth weight, which are leading causes of infant death,” says perinatologist Charles Lockwood, M.D., of the Yale University School of Medicine.
Stress triggers several reactions in a woman’s body. This includes the release of stress hormones such as cortisol, which can cause premature labor, explains Calvin Hobel, M.D., chairman of obstetrics and gynecology at Cedars-Sinai Medical Center in Los Angeles.
One culprit may be corticotropin-releasing hormone (CRH). This hormone is produced normally by the
placenta in increasing amounts as a pregnancy progresses, typically prompting labor at the end of the last trimester. When the mother is under stress, however, cortisol from her adrenal glands and another stress hormone, norepinephrine, turn on CRH production, which can start the clock ticking toward premature labor.
Stress hormones can also compromise the mother’s immune system, creating greater risk for uterine infection, which often goes undetected, adds Hobel.
Fetal development can be affected by a mother’s stress as well. Stress raises blood pressure, causing the release of norepinephrine, as mentioned. This combination can restrict the amount of blood that flows to her uterus, inhibiting fetal growth. Thus, even full-term babies can be underweight at birth.