PubMed Health⌕ Search

Biomedical subjects

M W Brinsmead

Publications and source records attributed to M W Brinsmead.

At least 19 recordsLinked to original sources
PubMed2000

Process measures in an antenatal smoking cessation trial: another part of the picture.

Data on provider and patient compliance can be crucial in understanding the degree of a health education program's effectiveness, as well as in identifying areas where the program requires modification. However, such data are rarely systematically reported in randomized trials. This report assesses the degree to which doctors and midwives complied with intervention protocols in a hospital antenatal smoking cessation trial, and also examines the program's acceptability to patients. Provider compliance was assessed principally via consultation audiotapes and provider-completed checklists. The audiotape analysis identified substantial compliance problems. For example, in relation to six specific smoking-related pregnancy risks, the proportions of Experimental Women informed about each individual risk ranged from 26 to 38% and the proportions receiving counselling items ranged from 52 to 79%. Doctors only informed a minority of Experimental Women of the increased risk of Sudden Infant Death Syndrome (28%) and of the presence of toxic chemicals in tobacco (21%). Comparison of compliance data from audiotapes and provider checklists revealed there was no significant agreement in three of four cases tested. Experimental Patients completed questionnaires to assess recall of smoking advice and to rate 12 program features. Of specific Experimental Program elements, the videotape (85%) received the highest level of positive patient ratings and the lottery (42%) the lowest. The process evaluation indicated that the Experimental Program needed some modification to increase its suitability for routine application. The findings also support the value of including an objective measure of provider compliance.

Female↗
PubMed1997

Predictors of smoking in pregnancy and attitudes and knowledge of risks of pregnant smokers.

This study examined the prevalence and predictors of smoking by pregnant women attending a public antenatal clinic. The prevalence of smoking in this population (n = 2577) was found to be 38.0% (95% CI 36.1-39.9%). A review of previous research investigating variables associated with smoking in pregnancy indicated that only three of 42 studies had used multivariate analysis. Using step-wise logistic regression analysis, five variables were found to be independent predictors of smoking in pregnancy: education (having 4 years or less high school), marital status (being unmarried), gravidity (being multigravida), age (being under 25 years) and language spoken at home (speaking English). The model correctly predicted 63.7% of cases. The knowledge and attitudes of pregnant smokers were also investigated using data from a sub-sample of consenting subjects. Three-quarters of the women claimed that they had reduced their smoking since discovering they were pregnant. However, their mean intake of 13.7 cigarettes daily remained at a hazardous level. Approximately half (51%) these smokers claimed to have tried to quit smoking in the current pregnancy. Most (61%) women said they believed smoking was definitely harmful to the unborn child. However, awareness and acceptance of specific risks were inadequate. Of the women in a current relationship, 72% said their partner was a regular smoker. Less than half (45%) the continuing smokers who had seen a doctor about their current pregnancy could recall being advised to stop smoking. There is a need for health care providers to adopt a more systematic and tailored approach to smoking cessation counselling. Efforts to convert quit attempts in pregnancy into sustained cessation represent a priority area of programme development and evaluation.

Journal Article↗
PubMed1997

A smoking cessation program at a public antenatal clinic.

OBJECTIVES: A randomized trial evaluated the impact of smoking cessation interventions on point prevalence and consecutive quit rates at an Australian public prenatal clinic. METHODS: Self-reports and urine cotinine tests confirmed patients' smoking status at the midpoint and end of pregnancy and 6 weeks postpartum. RESULTS: At all points, validated abstinence rates were significantly higher in the experimental group than in the control group. The rate of failed biochemical validation was significantly higher in the control group than in the experimental group. CONCLUSIONS: Prenatal clinic staff can significantly increase quit rates by using cognitive-behavioral strategies. Brief advice appears to be ineffective.

Australia↗
PubMed1995

Continuity of care by a midwife team versus routine care during pregnancy and birth: a randomised trial.

OBJECTIVE: To compare continuity of care from a midwife team with routine care from a variety of doctors and midwives. DESIGN: A stratified, randomised controlled trial. PARTICIPANTS AND SETTING: 814 women attending the antenatal clinic of a tertiary referral, university hospital. INTERVENTION: Women were randomly allocated to team care from a team of six midwives, or routine care from a variety of doctors and midwives. MAIN OUTCOME MEASURES: Antenatal, intrapartum and neonatal events; maternal satisfaction; and cost of treatment. RESULTS: 405 women were randomly allocated to team care and 409 to routine care; they delivered 385 and 386 babies, respectively. Team care women were more likely to attend antenatal classes (OR, 1.73; 95% CI, 1.23-2.42); less likely to use pethidine during labour (OR, 0.32; 95% CI, 0.22-0.46); and more likely to labour and deliver without intervention (OR, 1.73; 95% CI, 1.28-2.34). Babies of team care mothers received less neonatal resuscitation (OR, 0.59; 95% CI, 0.41-0.86), although there was no difference in Apgar scores at five minutes (OR, 0.86; 95% CI, 0.29-2.57). The stillbirth and neonatal death rate was the same for both groups of mothers with a singleton pregnancy (three deaths), but there were three deaths (birthweights of 600 g, 660 g, 1340 g) in twin pregnancies in the group receiving team care. Team care was rated better than routine care for all measures of maternal satisfaction. Team care meant a cost reduction of 4.5%. CONCLUSION: Continuity of care provided by a small team of midwives resulted in a more satisfying birth experience at less cost than routine care and fewer adverse maternal and neonatal outcomes. Although a much larger study would be required to provide adequate power to detect rare outcomes, our study found that continuity of care by a midwife team was as safe as routine care.

Adult↗
PubMed1995

Smoking cessation in pregnancy: a survey of the medical and nursing directors of public antenatal clinics in Australia.

Smoking is a major cause of adverse pregnancy outcomes. However limited data are available documenting the perceptions of care providers in this area. This mail survey undertaken in 1992-1993 aimed to assess the smoking cessation practices of Australian public antenatal clinics. Questionnaires were returned by 140 (80%) of the 175 eligible hospitals, 83 (48%) medical directors and 108 (62%) nursing directors. Smoking advice was rated an essential activity at the first antenatal visit by 69% of responding directors. Nonetheless, only 12% of clinics indicated they offered relevant training and 4% reported written policies. Results also indicate senior staff may have suboptimal levels of awareness of smoking risks. Clinics used a narrow array of strategies to promote cessation. Almost one-third of directors said they advised smokers to cut down rather than stop smoking completely. There is a need for antenatal clinics to implement integrated strategies for the detection and treatment of pregnant smokers including staff training and modifications to the clinics' environment. In addition, major health promotion agencies need to develop effective smoking cessation programmes designed specifically for use in antenatal clinics and to monitor their on-going implementation.

Australia↗
PubMed1993

Plasma corticotropin-releasing hormone, beta-endorphin and cortisol inter-relationships during human pregnancy.

To investigate the dynamic relationships among corticotropin-releasing hormone (CRH), beta-endorphin (beta EP), cortisol and obstetric events during pregnancy, blood samples were collected from 193 women at 28 weeks, 38 weeks, during labour and on the second postnatal day. Cord blood at delivery was also obtained. We found that: (1) Maternal plasma CRH, beta EP and cortisol rose from 28 to 38 weeks. (2) During the third trimester maternal plasma CRH and beta EP were correlated (r = 0.30, p < 0.001). (3) During labour, no correlations were found among maternal plasma CRH, beta EP and cortisol. (4) Maternal CRH at labour and the duration of labour were not correlated. (5) Maternal plasma CRH tended to be higher in women who delivered early (more than seven days prior to estimated date of confinement [EDC]) relative to those who were on time (within seven days' EDC) or late (greater than seven days after EDC). (6) CRH in maternal plasma at labour and cord blood were correlated (r = 0.29, p < 0.05) as were maternal and fetal beta EP (r = 0.43, p < 0.001). (7) Fetal obstetric difficulty was correlated with fetal beta EP (r = 0.54, p < 0.001). Our findings support the hypothesis that maternal plasma CRH regulates maternal beta EP during the third trimester, but other factors are involved during labour and in response to maternal obstetric stress.

Adult↗
PubMed1990

Urinary corticotropin-releasing hormone immunoreactivity is elevated during human pregnancy.

Plasma corticotropin-releasing hormone immunoreactivity (CRH IR) rises with gestational age in women. In order to investigate the physiological changes of the hormone in pregnant women's urine, CRH IR was measured by radioimmunoassay in urine collected over a 24-hour period, a blood sample and a subsequent single collection of urine after the 24-hour collection (spot urine). Plasma CRH IR in pregnant subjects, 8682.8 +/- 2063.0 pg CRH IR/ml plasma (mean +/- SEM, n = 25), was significantly higher than that in the non-pregnant controls (7.2 +/- 1.6 pg/ml, n = 5; separate t = 4.21, p = 0.0003, d.f. = 24). Similarly, pregnant women had higher spot urine CRH IR - 54.6 +/- 15.5 pg/mumol creatinine (Cr) versus 5.0 +/- 0.5 pg/mumol Cr (separate t = 3.20, p = 0.0038, d.f. = 24.0) - and 24-hour urine CRH IR - 13.7 +/- 1.2 pg/mumol Cr compared with 7.7 +/- 0.8 pg/mumol Cr (separate t = 4.28, p = 0.003, d.f. = 24.4) than the non-pregnant cohort. The difference between urinary excretion of CRH IR as estimated by 24-hour urine (13.7 +/- 1.2 pg/mumol Cr) and spot urine (54.6 +/- 15.5 pg/mumol Cr) indicated that CRH IR in 24-hour urine may be degraded during storage. The weak associations between plasma and 24-hour urine CRH IR of pregnant women (correlation coefficient r = 0.34, p greater than 0.1), and total 24-hour urine and spot urine CRH IR (r = 0.25, p less than 0.1) further indicate CRH degradation. Plasma and spot urinary CRH IR, however, were strongly correlated (r = 0.80, p = 0.001). The total CRH IR excreted as estimated from the spot urine value (0.5 +/- 0.1 micrograms/day) compared with the total filtered load of CRH IR in the pregnant group (1306.9 +/- 324.6 micrograms/day) showed that 99.97% of the filtered CRH IR was reabsorbed or metabolized by the kidneys. Acidic gel chromatography of spot and 24-hour urine samples showed a CRH IR peak at CRH41 standard elution position (Kd = 0.5), indicating that the molecular form in urine is similar to the 41-residue standard. Pregnancy-induced hypertension correlated positively with plasma CRH IR (r = 0.62, p less than 0.001) and spot urine CRH IR (r = 0.46, p less than 0.01), and negatively with parity (r = -0.60, p less than 0.001). Plasma CRH IR and parity also negatively correlated (r = -0.41, p less than 0.05).(ABSTRACT TRUNCATED AT 400 WORDS)

Corticotropin-Releasing Hormone↗
PubMed1987

Postnatal disappearance of the pregnancy-associated reduced sensitivity of plasma cortisol to feedback inhibition.

We recently observed that the characteristic insensitivity of the pituitary-adrenal system in women to feedback inhibition during pregnancy persists for at least four days postnatally. We therefore examined women during the first five weeks after delivery to assess when the sensitivity of plasma cortisol to glucocorticoid inhibition returns to normal. Dexamethasone (DEXA, 1 mg) was ingested at 11 pm by normal healthy women, once between the 3rd and 27th postnatal days, and again on day 35. Blood plasma was collected at 4 pm on the following day for cortisol assay. Plasma cortisol levels (nmol/L, mean +/- sem [n]) after DEXA in the first two weeks (216 +/- 28, [47]) were higher (p less than 0.001) than in nonmedicated nonpregnant women (47.4 +/- 8.9 [12]) and were normal by the 35th day after delivery (41.7 +/- 4.8 [74]). A negative association was found between post-DEXA cortisol and time after delivery in the first 4 post-partum weeks (r = -0.46, p less than 0.001). The study confirms that insensitivity of plasma cortisol to feedback inhibition persists beyond normal pregnancy in a significant proportion of healthy women for two to three weeks, and is absent by the 5th postnatal week.

Dexamethasone↗
PubMed1987

The nonsuppressibility of plasma cortisol persists after pregnancy.

To determine if normal balance is restored to the hypothalamic-pituitary-adrenal axis after pregnancy, we compared the dexamethasone suppressibility of plasma cortisol in women four days after delivery of their infant, with that of nonpregnant women. Plasma concentrations of cortisol before dexamethasone administration were similar in the post-partum women and in women taking oestrogen contraceptives, but both were higher than in normally cycling women. After dexamethasone, plasma cortisol in the post-partum women was significantly higher than in both oestrogen-taking and normally cycling nonpregnant women. The reduced dexamethasone-suppressibility of plasma cortisol, which is characteristic of pregnancy, extends into the post-partum period.

Contraceptives, Oral↗
PubMed1985

Insulin-like growth factor receptor in fetal lamb liver: characterization and developmental changes.

Multiplication-stimulating activity (MSA), an insulin-like growth factor (IGF) (rat IGF II), binds to extracts of many tissues from fetal lambs. We now report the presence of high concentrations of a glycoprotein receptor with a high affinity for MSA-II in microsomes prepared from fetal lamb liver. The binding of radiolabeled MSA-II is inhibited by IGF but not by insulin, human, and ovine GH, ovine PRL, ovine placental lactogen, and mouse epidermal growth factor. The relative potencies of human IGF II, human IGF I, and MSA-II in competing with [125I]MSA-II for binding to this receptor are 100:17:3.5 by weight. Binding is pH, time, and temperature dependent. Gel permeation chromatography of the Triton X-100 soluble receptor indicates a hydrodynamic radius of 6.8 nm. Specific binding increases from mid- to late gestation and is associated with changes in both the affinity and concentration of receptors. Receptor concentration increases from 7.95 +/- 3.94 pmol/mg (mean +/- SE) at 78 days gestation to 15.8 +/- 4.3 pmol/mg at 134-140 days (P less than 0.05), whereas receptor affinity decreases from 1.14 +/- 0.34 X 10(9) liter/mol to 0.63 +/- 0.14 X 10(9) liter/mol over this period (P less than 0.05). The presence of very high concentrations of an IGF receptor in fetal lamb liver suggest that this organ may be a major target for IGF action in fetal life. The increase with advancing gestational age of the concentration of IGF receptors which have preferential specificity for IGF II may function to increase the responsiveness of the fetal lamb liver to IGF II stimulation and so compensate for the decline in plasma concentrations of this growth factor which occur near birth.

Animals↗
PubMed1985

An examination of the proposed roles of placental lactogen in the ewe by means of antibody neutralization.

The physiological role of placental lactogen (PL; chorionic somatomammotrophin) in the ewe has been investigated by infusion of ewes (n = 3) on day 131 of pregnancy with sufficient ovine PL (oPL) antibody to neutralize circulating oPL for at least 12 h. Effectiveness of the antibody neutralization was defined both in vitro and in vivo according to rigorous criteria. Control ewes (n = 3) were infused simultaneously with an equivalent amount of pooled goat gamma globulin. Since both sets of ewes had previously been catheterized with jugular, utero-ovarian and femoral vein catheters and a femoral arterial catheter, it was possible to measure whole body glucose kinetics as well as muscle and uterine glucose, free fatty acid (FFA) and 3-hydroxybutyrate extraction. In addition, plasma levels of insulin, GH, prolactin, insulin-like growth factor-I (IGF-I), IGF-II, progesterone and cholesterol were determined in femoral arterial samples. Neutralization of maternal oPL did not significantly affect whole body glucose metabolism, uterine and muscle glucose extraction, or 3-hydroxybutyrate extraction by muscle. A trend towards lower plasma FFA levels was observed after prolonged infusion, but was not statistically significant. However, plasma insulin levels rose significantly during antibody infusion after an early fall. These observations are rationalized in terms of the known requirements of ruminant metabolism during pregnancy, and contrasted with the accepted model for the role of human PL in the metabolic adjustments of pregnancy. No change in plasma IGF-I, IGF-II or GH was observed, providing no support for the concept that oPL is responsible for maternal somatomedin generation during pregnancy. Similarly, plasma prolactin did not differ between antibody-treated and control groups. Finally, antibody neutralization had no influence on either plasma progesterone or cholesterol, mitigating against a role for oPL in progesterone production during late pregnancy in the ewe.

Animals↗
PubMed1982

Effect of streptozotocin on foetal lambs in mid-pregnancy.

Streptozotocin was administered to 11 foetal lambs in utero at 70-85 days of gestation. Four of the foetuses survived and, when delivered at 134-142 days, exhibited significant growth retardation of the trunk and delayed osseous maturation in limb bones. The foetal kidneys and livers were most affected, but in three of the four foetuses, the weight of the brain was appropriate for gestational age. Likewise head size, measured by length or biparietal diameter, was normal. The insulin content of the foetal pancreas was less after streptozotocin-treatment than in normal animals of a similar gestation. Two streptozotocin-treated foetuses, catheterized at 120 days gestation, had higher glucose concentrations and lower insulin responses than in controls when infused with glucose. Plasma concentrations of ovine placental lactogen were lower in streptozotocin-treated foetuses than in controls, but serum somatomedin-like activity measured by receptor assay was greater than in controls. When the foetal serum was chromatographed on Sephadex G150 at acid pH, the major size about 10000). The foetal growth retardation associated with streptozotocin administration in mid-pregnancy may be due to insulin deficiency, but the normal brain weight which occurred suggests that some other factor (possibly a somatomedin) regulates the growth of this organ.

Animals↗
PubMed1981

Fetal and material ovine placental lactogen during hyperglycaemia, hypoglycaemia and fasting.

Hyperglycaemia was produced in chronically catheterized fetal lambs and pregnant-ewes by the infusion of glucose into the fetus. Plasma concentration of placenta lactogen did not change significantly in either fetal or maternal circulation. Fetal and maternal hypoglycaemia was induced by administration of insulin to the fetus and ewe separately. Plasma concentrations of placental lactogen in the fetus did not change significantly but maternal plasma concentrations fell slightly after hypoglycaemia in either fetus or ewe. Plasma concentrations of placental lactogen rose in both the ewe and fetus during prolonged fasting of the ewe. These results neither confirm nor refute a role for placental lactogen in intermediary metabolism of the pregnant ewe and fetus but glucose concentration alone is unlikely to be a significant factor in the control of secretion of this hormone.

Animals↗