After terror, moms' stress affects kids.

Infants born to women who developed posttraumatic stress disorder during pregnancy have, as their mothers do, unusually low concentrations of the hormone cortisol, researchers have found. That could partly explain why such children themselves face a high risk of developing the disorder, called PTSD.

Psychiatrist Rachel Yehuda of the Bronx Veterans Affairs Medical Center in New York and her colleagues studied 38 women who were pregnant on Sept. 11, 2001, and narrowly escaped that day's terrorist attacks on the World Trade Center. The researchers obtained saliva samples from each woman and each child when the children were 1 year old. The researchers also tested the mothers for PTSD.

Women with the most-severe PTSD symptoms had infants with the lowest cortisol concentrations, and women free of the disorder had children with the most cortisol, the researchers report in the July Journal of Clinical Endocrinology Metabolism.

Past research has suggested that children can develop low concentrations of cortisol, a stress-response hormone, because of neglectful or abusive parenting. Yehuda's team notes that poor parenting might be common in families affected by PTSD. But according to the researchers, the new finding hints that genetic or prenatal influences are also important, since the link between maternal PTSD and children's cortisol concentrations showed up before bad parenting could have taken its full toll.