Pregnant women become insensitive to cold stress

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 ± 2.5 weeks gestation) and about 8 weeks postpartum (mean 7.8 ± 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

Changes in plasma cortisol and catecholamine concentrations in response to massage in preterm infants.

The biochemical and clinical response to massage in preterm infants was assessed. Eleven stable infants, of 29 weeks' median gestational age, median birth weight 980 g, and median postnatal age 20 days, were studied. Blood samples were obtained for the determination of adrenaline, noradrenaline, and cortisol 45 minutes before the start of massage and approximately one hour after completion of massage. Cortisol, but not catecholamine, concentrations decreased consistently after massage (median difference -35.8 nmol/l; 95% confidence interval -0.5 to -94.0, Wilcoxon matched pairs). There was a slight decrease in skin temperature (median difference -0.36 degrees C, 95% confidence interval -0.09 to -0.65) but there was no change in oxygenation or oxygen requirement. This study has shown that it is possible to detect an objective hormonal change following a supposedly 'non-therapeutic' intervention in preterm infants. The development of such methods of assessment are likely to be of particular relevance in the extremely immature or ill neonate in whom behavioural evaluation cannot play more than a limited part

Fetal Plasma-Cortisol and Beta-Endorphin Response to Intrauterine Needling

The purpose of this study was to investigate whether the fetus mounts a hormonal stress response to a potentially painful procedure, intrauterine needling

Variation in anaesthesia for the laser treatment of retinopathy of prematurity - a survey of ophthalmologists in the UK

Purpose Laser treatment for retinopathy of prematurity (ROP) may be associated with systemic stress for the infant. No national consensus on the optimum method of anaesthesia for the treatment of ROP currently exists. This study ascertains the anaesthetic practices employed for the treatment of ROP by ophthalmologists in the United Kingdom (UK), and also their attitudes towards these practices.Materials and methods A postal questionnaire was sent to 46 consultant ophthalmologists identified as performing treatment for ROP in the UK. The consultants were asked to estimate the annual number of babies with ROP that they treated with laser, what methods of anaesthesia they employed, for comments regarding the arrangements for, and types of anaesthesia employed and whether they believed that the neonatal stress response to laser treatment was associated with a significant risk of systemic complications.Results In all, 35 (76%) questionnaires were returned. A total of 30 (86%) respondents reported performing laser treatment for ROP. Of these, 15 (50%) used general anaesthesia for all cases and 11 (37%) intravenous sedation combined with topical anaesthesia for all cases. Oral sedation combined with topical anaesthesia, rectal chloral hydrate and paracetamol combined with topical anaesthesia, intravenous ketamine combined with topical anaesthesia, and subtenon's local anesthesia were used by one (3%) respondent each. There were no ophthalmologists using subconjunctival or topical anaesthetic alone or treating without anaesthesia.Conclusion This survey reveals considerable variation in practice among UK ophthalmologists regarding the anaesthetic methods employed in the treatment of ROP, and their beliefs regarding the systemic stress associated with treatment