Results
Fig 1 shows that the controls showed the expected highly significant increase in saliva cortisol 20 minutes after immersing the hand in ice cold water (p < 0.001). This response was generally absent in the group of pregnant women who showed no significant mean increase, despite a small increase in some individuals. The effect was quite variable in the postpartum women. Some showed a large increase, others not and the increase for the group as a whole was not significant. The results were similar after excluding the two who were not breast-feeding.
Fig 2 shows the differences between the three groups. Fig 2a shows that the baselines were very different, the pregnant group having the highest values, the postpartum intermediate and the controls had the lowest values. Fig 2b shows the reverse pattern for the responsivity. There was a significant difference in the degree of response between the pregnant and control groups (p < 0.05) but not between the other groups.