(returning late to the party)
In my reading I just came across this impressive paper regarding maternal stress:
"Stress during Pregnancy and Offspring Pediatric Disease: A National Cohort Study"
Description: "The purpose of this study was to assess the association between common psychosocial stress during pregnancy and the risk of a wide range of offspring diseases."
Based on "population-based sample of mothers with live singleton births (n = 66,203; 71.4% of those eligible)". (n = 66,203 is a respectable number)
Also it is exceptionally well referenced (~90 other bits of research referred to by my count).
Here is their definition of "stress":
Here are some of my favourite findings:
The observed association between maternal stress during pregnancy and
child health may represent long-term consequences of subtle
adaptations in multiple organ systems to the intrauterine environment.
The potential biological mechanisms underlying such developmental
plasticity, including epigenetic processes and changes at the
molecular, cellular, and organ level in the offspring.
Specifically, in relation to maternal stress during pregnancy,
numerous subclinical alterations in physiology, including changes in
immune, brain, cardiovascular, autonomic, endocrine, and metabolic
function, have been described, such as changes in fetal heart rate,
insulin resistance, increased concentrations of immunoglobulin E in
cord blood and changes in hypothalamic–pituitary–adrenal (HPA) axis
function. .. Elevated stress levels across pregnancy have also been associated with changes in production of pro-inflammatory cytokines in the offspring.
Adjusting for maternal smoking during pregnancy, hypertension, and
diabetes did not alter associations between maternal stress during
pregnancy and child health. Maternal nutrition is another candidate
mediator, because stress is related to quality of nutrition, and a
relationship between nutrition during pregnancy and a range of
offspring diseases has been well documented. ... Adjusting for birth
weight and length of gestation had little effect on associations.
I was going to post this anyway before re-reading the beginning of the conclusion:
This study suggests that maternal life stress during pregnancy may
be a common risk factor for a wide range of diseases in the offspring;
however, we found almost no evidence for adverse health consequences
of maternal emotional stress during pregnancy.
There seems to be some other research out there, though this paper is interesting.
 changes in HPA axis activity have been associated not only with maternal stress during pregnancy (Kapoor et al. 2008), but also with a wide range of diseases, including mental disorders (Goodyer et al. 2001), respiratory diseases (Priftis et al. 2009), diseases of the skin (Buske-Kirschbaum et al. 2010), and infectious diseases (Bailey et al. 2003). However, although the HPA axis has long been proposed as a causal link between early adversity and lifelong disease risk.
 dysregulation of cytokine production has been associated with certain mental disorders (Conti and Fulcheri 2010; Raison et al. 2010); infectious diseases (Subauste et al. 1995); diseases of the eye, such as conjunctivitis (Niederkorn 2008); ear, such as otitis media (Smirnova et al. 2002); respiratory system, such as asthma (Finkelman et al. 2010); digestive system, such as disorders related to gastrointestinal motility (De Winter and De Man 2010); urogenital system, such as urinary tract infection (Mak and Kuo 2006); and skin, such as atopic dermatitis (Miraglia del Giudice et al. 2006).