Kuzawa - prenatal stress  

So there’s more and more evidence now that if a mother is stressed during pregnancy, that this can permanently alter how the stress system in the offspring operates, and influence how they respond to stress. And so we have; there are good animal models of that, there have been for a long time showing that if you stress out say pregnant rats that the offspring will have altered stress physiology. But now we have more and more evidence that this also operates in humans.  

And so one example of that is actually is one of my former PhD students, Zaneta Thayer, who worked in New Zealand. And she worked with kind of a multiethnic population there. And she looked at measures of deprivation and stress during pregnancy; so she actually measured women during pregnancy; she measured their cortisol levels which is a stress hormone. And then she followed up with the babies after birth. And of course it’s not ethical to stress out a baby, but we already do that when they go to the doctor and they get vaccines and this is a very stressful event that they already go through. What she did is she looked at stress hormones before and after that as a way to see how they are responding to that stress. And interestingly, she found a very clear relationship. The more stressed out the mother was during pregnancy, based upon her what she reported during pregnancy itself, the larger the stress hormone reaction of her baby at six weeks of age to that vaccination. Now we don’t know that that necessarily traces back to the prenatal environment. It could be that those women who were stressed during pregnancy, also raised their kids differently in those first few weeks. But, it seems likely that part of what might be going on actually is an intergenerational effect of stress during pregnancy, that’s a reasonable kind of working hypothesis.