Stephen W. Lindow

The effect of morphine and naloxone administration on plasma oxytocin concentrations in the first stage of labour

OBJECTIVE We Investigated the effect of an oplate (morphine) and an opiate antagonist (naloxone) on the maternal secretion of oxytocin in the first stage of labour.

Morphine Suppresses the Oxytocin Response in Breast-Feeding Women

The activity of opiate-mediated regulatory mechanisms of oxytocin secretion during breast-feeding was studied by the administration of either morphine, naloxone or placebo to women prior to the commencement of breast-feeding. Seventeen healthy women in the first week after delivery who had established lactation were ramdomized to receive either intravenous morphine 5 mg (n = 6), naloxone 2.4 mg (n = 6) or a placebo, sterile water (n = 5), which was given prior to commencement of breast-feeding. Oxytocin levels were measured by radioimmunoassay prior to initiation of breast-feeding and then at 2-min intervals until the feed was complete. Breast-feeding produced a significant rise in oxytocin levels in the control and naloxone groups but no significant rise in the patients given morphine. There was a significant reduction in oxytocin response following morphine administration when compared to placebo but not between naloxone and placebo. In conclusion, oxytocin secretion to breast-feeding is inhibited by exogenous morphine when compared to a control group but the administration of naloxone did not produce a significant difference from control.

Determination of mercury in hair by coupled CVAA-ICP-MS

This paper describes the coupling of a cold vapour atomic absorption (CVAA) instrument with an ICP-MS to obtain mercury concentration information and stable isotopic ratio data. The sample preparation procedure, based on microwave digestion, describes the decomposition of small masses of hair using 7 ml digestion vessels, which will enable the methodology to be used subsequently with neonatal hair samples. The results based on a CRM hair sample and spiked real samples indicated that the digestion method with direct CVAA analysis gave recoveries of around 100% with a corresponding RSD of 3.5%. The interfacing of the CVAA instrument to the ICP-MS was relatively simple and enabled isotopic data to be obtained in tandem with CVAA quantitative data. Some ICP-MS mercury memory problems were observed with the coupled CVAA-ICP-MS but these did not affect either the CVAA determination or isotopic ratio estimations.

The effect of emotional support on maternal oxytocin levels in labouring women

OBJECTIVEnThe presence of a supportive companion to women in labour has been found to reduce the duration of labour and the incidence of oxytocin augmentation. The mechanism which produces this improvement is unknown but work in animals suggests that environmental disturbance produces changes in endogenous oxytocin secretion. This study was carried out to assess maternal oxytocin secretion in relation to the presence of a supportive companion in labour.nnnSTUDY DESIGNnA randomised controlled trial involving allocation of unsupported women in the first stage of labour to a period of 1 h with a supportive companion or 1 h without. Sixteen women with uncomplicated singleton pregnancies who were in the active phase of the first stage of labour were studied. Maternal oxytocin levels were assayed by radioimmunoassay for 16 min (eight specimens) before and after the support or control period.nnnRESULTSnThere are no differences between maternal oxytocin levels in the two groups of patients. There was no difference in either of the two groups between the oxytocin levels pre and post the support/control period.nnnCONCLUSIONSnOne hour of birth support in the first stage of labour did not improve maternal oxytocin levels when compared to a control group.

The effect of morphine and naloxone administration on maternal oxytocin concentration in late pregnancy

OBJECTIVE Modification of the inhibitory control of oxytocin secretion by endogenous opiates in late pregnancy may be one of the factors involved in the onset of labour. The interrelationships between exogenously administered opioids and oxytocin may demonstrate activity of this control mechanism.

Maternal hair selenium levels as a possible long-term nutritional indicator of recurrent pregnancy loss

BackgroundApproximately 1% of all couples trying to conceive will suffer from recurrent pregnancy loss (RPL). Nutritional deficiencies have been postulated as a possible cause of RPL and in particular, selenium deficiency has been associated with reproductive failure in animal studies and more recently, in some human studies. This study was undertaken to assess the maternal hair selenium levels in women with RPL without an identified cause and to compare these results with those of women with successful reproductive histories.MethodsTwenty four patients with RPL and twenty four control subjects with at least one successful pregnancy and no pregnancy failures, who were matched for age and ethnicity, were recruited. A questionnaire was completed, which included demographic and social information and a dietary history. Hair samples were collected and analyzed for selenium content by inductively coupled plasma mass spectrometry.ResultsThe control subjects had a higher mean income and had completed more years of education compared with the RPL patients. There was no significant difference in the intake of selenium rich foods between the 2 groups. The patients, however, consumed significantly more fruit, cheese, potatoes and chocolate than the controls. The median (range) selenium content was 0.80xa0ppm (0.19-4.15) and 0.68xa0ppm (0.43-3.76) in patients and controls respectively (Mann Whitney U test 209.5 pu2009=u20090.74).ConclusionsWhile there were significant differences in the 2 groups with regard to resources, education and diet our results show that hair selenium concentrations and dietary selenium intake, were similar in the two groups. Both groups had low levels of this important element.

Analysis of heavy metal toxins in maternal and fetal hair

Objective To analyse maternal and fetal hair lead levels to assess chronic exposure. To evaluate if leaded petrol is associated with high levels of lead in the maternal and fetal hair. A series of epidemiological studies showed high levels of lead to cause permanent fetal neurological damage. Maternal and fetal hair lead levels are shown to be low in countries using unleaded petrol. But many countries, particularly African continent, are still using leaded petrol. Mother/baby pairs from centres in Nigeria, UK, Sudan and Cape Town were included in this study. Samples were taken within 3 days of delivery from the consented mothers and their babies. Lead level was analysed as per standard protocol in the same assay in Hull University by inductively coupled plasma mass spectrometry. The results are shown in the table and are variable and indicate that petrol is not the only source of lead exposure. The Maternal: Fetal ratio varies and seems protective of high levels in the mother. Table 1 Abstract PF.31 Table Centre Maternal Hair Geometric mean(range) Ppm (parts per million) Fetal Hair Geometric mean (range) ppm Hull (United Kingdom) 1.5 1.4 Unleaded petrol (0.41-5.44) (0.26-5.9) N=26 N=22 Ibadan 33.2 1.5 (Nigeria) (0.76-355.4) (0.98-3.6) Leaded petrol N=13 N=10 Khartoum 14.4 1.2 (Sudan) (3.3-195.8) (0.48-11.9) Unleaded petrol N=24 N=23 Cape Town A 5.1 0.24 (South Africa) (0.20-44.0) (0.01-3.04) Leaded Petrol N=30 n=27 Cape Town B 3.8 0.73 (South Africa) (0.70-14.6) (0.24-8.5) Transition to Unleaded Petrol N=30 N=25