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.
Young maternal age, independent of other risk factors, increases the chance of adverse pregnancy outcomes, according to a study in the April 27 New England Journal of Medicine. Between 1970 and 1990, researchers analyzed birth records of 134,088 first-born infants of white, middle-class Utah women, ages 13 to 24. This group was chosen because other social and behavioral risk factors predicting poor birth outcomes were greatly reduced. Mothers younger than 17 were twice as likely to have low-birth-weight infants or give birth prematurely, than mothers ages 20 to 24. Mothers ages 18 to 19 had less risk for premature or low-birth-weight infants than the youngest mothers, but more than those ages 20 to 24. Those younger than 17 were also most likely to have an infant small for its gestational age.
ATLANTA — An investigation of reproductive outcomes in black and white female college graduates of similar socioeconomic status found that black graduates had more than one and a half times the risk of pre-term delivery and two and a half times the risk of having low-birth-weight infants. The study outlining these findings was published in the Aug. 1, 1992, issue of the American Journal of Epidemiology.