Stress during the final trimester of pregnancy can result in premature birth or low birth weight, according to a study funded by the National Institute of Child Health and Human Development.
Ninety married, upper middle-class women were asked to complete a questionnaire detailing their economic status, health habits, medical history and perceived stress level. For each unit increase on the questionnaire's stress scale, researchers noticed a 55.03 gram decrease in infant birth weight. Women who were anxious about their pregnancies were also more likely to give birth prematurely. Each stress-scale-unit increase was associated with a three-day decrease in infant gestational age at birth.