Higher lifetime trauma among women is associated with decreased birthweight among male offspring, according to a study published Sept. 6 in The Journal of Pediatrics

Julie D. Flom, M.D., M.P.H., from Kravis Children's Hospital in New York City, and colleagues evaluated associations between maternal lifetime traumatic stress and offspring birthweight among 314 mother-infant dyads (41 percent Hispanic; 26 percent black). A 3-cm scalp-nearest maternal hair segment collected at birth was assayed to reflect cumulative third-trimester cortisol secretion.

Lower birthweights

The researchers found that 63% of women reported at least one traumatic event. Prenatal cortisol modified the correlation between maternal trauma and infant birthweight. Male infants whose mothers had higher lifetime trauma and increased cortisol had significantly lower birthweights.

Among boys exposed to the 90th percentile of cortisol, a one-unit increase in trauma score was associated with a 0.19-unit decrease in birth weight for gestational age z-scores. These associations were not significant among female infants regardless of cortisol level.

"These findings underscore the need to consider complex interactions among maternal trauma, disrupted in utero cortisol production, and fetal sex to fully elucidate intergenerational effects of maternal lifetime trauma," the authors write.