title: Pregnant women become insensitive to cold stress.
abstract: BACKGROUND: The function of the hypothalamic-pituitary-adrenal (HPA) axis is known to be altered during pregnancy, but it has not been tested with a natural stressor. METHODS: A group of pregnant women (n = 10) were tested towards the end of pregnancy (mean 36.8 PlusMinus; 2.5 weeks gestation) and about 8 weeks postpartum (mean 7.8 PlusMinus; 1.5 weeks), together with a matched control group, with a one minute cold hand stressor test. Saliva samples were collected before and 10 and 20 minutes after the test, and stored for later radioimmunoassay of cortisol. RESULTS: The control group showed a highly significant response to the test. The pregnant group showed no response, and the postpartum group a variable but non significant one CONCLUSIONS: This shows that the HPA axis becomes hypofunctional to a natural stressor at the end of pregnancy. It is suggested that one possible evolutionary function for this is to protect the fetus from the stress responses of the mother.
authors.affiliation: Wolfson and Weston Research Centre for Family Health, Institute of Reproductive and Developmental Biology, Faculty of Medicine, Imperial College, Hammersmith Campus, Du Cane Road, London, W12 0NN, UK. v.glover@ic.ac.uk
authors.forename: Martin
authors.initials: M
authors.lastname: Kammerer
authors.forename: Diana
authors.initials: D
authors.lastname: Adams
authors.forename: Brida von
authors.lastname: Castelberg Bv
authors.forename: Vivette
authors.initials: V
authors.lastname: Glover