News of a further study looking at possible prenatal pathways for the intergenerational transmission of trauma.

A Californian study looked at placental-fetal stress physiology in 295 pregnant women, 43% of whom had experienced trauma as a child. The researchers were looking at levels of placental corticotropin-releasing hormone (pCRH). After week 19 of gestation the production of pCRH was about twice as high in women who had experienced childhood trauma, compared to those women who had not. In their analysis the researchers controlled for factors such as relevant sociodemographic factors, substance use, and depressive symptoms.

Raised levels of placental CRH have been associated with a range of later difficulties for the child. See, for example, this summary which describes a variety of related issues, including a greater likelihood of preterm delivery, altered growth patterns within the first two years of life and cortical thinning in 6-9 year olds. 

One possible pathway for this influence is that the mother's early trauma may predispose a stress reaction in her to later experiences. This reaction would in turn raise cortisol levels, stimulating the production of pCRH.

There is increasing interest in the direct effects that maternal mental health may have upon the child even before birth. A previous post on this blog referred to fetal brain changes associated with prenatal maternal depression. These studies underline the importance of adequate support for mothers and especially for those who are emotionally or psychologically vulnerable.

Thanks to NEJM Journal Watch