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Biomedical subjects

M H Hall

Publications and source records attributed to M H Hall.

At least 19 recordsLinked to original sources
PubMed2006

Absence of conception after caesarean section: voluntary or involuntary?

BACKGROUND: Women who deliver by caesarean section have been shown to be less likely to have a subsequent pregnancy. It is not clear whether this is due to a direct effect of the procedure on future fertility or due to deliberate avoidance of a future pregnancy. OBJECTIVE: To investigate whether absence of conception following caesarean section is voluntary or involuntary. DESIGN: Follow up of a population-based retrospective cohort. SETTING: Grampian region, Scotland. POPULATION: Women who had no further viable pregnancies within 5 years of an initial delivery. METHODS: Cases included women who delivered their first child by caesarean section between 1980 and 1995 but had no further viable pregnancies by December 2000. Controls included women who delivered their first child during the same period, by means of either spontaneous vaginal delivery (SVD) or instrumental vaginal delivery (IVD), and who had no further viable pregnancies by December 2000. Eligible women were identified from the Aberdeen Maternity and Neonatal Databank (AMND) and sent postal questionnaires to determine the extent to which not conceiving after first delivery was voluntary and the reasons for avoiding further pregnancies. Characteristics of the different mode of delivery groups were compared using univariate techniques. MAIN OUTCOME MEASURES: Extent to which absence of conception following an initial delivery by caesarean section is voluntary. RESULTS: Questionnaires were returned by 3204 (60%) of 5300 women identified from the AMND. Of these, 1675 women had not conceived at all during the follow-up period (median duration = 13 years). Absence of conception was voluntary in 488 (69%; 95% CI 66-73%) women following caesarean section, 340 (71%; 95% CI 67-76%) following SVD and 354 (72%; 95% CI 68-76%) following IVD. Few women considered seeking fertility treatment (caesarean section = 72 [10%], SVD = 50 [11%], IVD = 39 [8%]). Of the women who decided to delay or avoid a further pregnancy, fewer women who delivered by SVD reported that the birth experience influenced their decision (caesarean section = 163 [32%], SVD = 67 [18%], IVD = 136 [35%]; P < 0.001). CONCLUSIONS: Irrespective of mode of delivery, not conceiving following the birth of the first child is mainly voluntary. The experience of the previous birth is one of several factors affecting women's decisions to avoid a subsequent pregnancy.

Adult↗
PubMed2001

Holding up a mirror: changing obstetric practice through criterion-based clinical audit in developing countries.

The objective of the study described is to assess the feasibility and effectiveness of using a criterion-based clinical audit to measure and improve the quality of obstetric care at the district hospital level in developing countries. The focus is on the management of five life-threatening obstetric complications--hemorrhage, eclampsia, genital tract infection, obstructed labor and uterine rupture was audited using a "before and after" design. The five steps of the audit cycle were followed: establish criteria of good quality care; measure current practice (Review I); feedback findings and set targets; take action to change practice; and re-evaluate practice (Review II). Systematic literature review, panel discussions and pilot work led to the development of 31 audit criteria. Review I included 555 life-threatening complications occurring over 66 hospital-months; Review II included 342 complications over 42 hospital-months. Many common areas for improvement were identified across the four hospitals. Agreed mechanisms for achieving these improvements included clinical protocols, reviews of staffing, and training workshops. Some aspects of clinical monitoring, drug use and record keeping improved significantly between Reviews I and II. Criterion-based clinical audit in four typical district hospitals in Ghana and Jamaica is a feasible and acceptable method for quality assurance and appears to have improved the management of life-threatening obstetric complications.

Adult↗
PubMed2001

Can obstetric complications explain the high levels of obstetric interventions and maternity service use among older women? A retrospective analysis of routinely collected data.

OBJECTIVE: To determine whether the higher levels of obstetric intervention and maternity service use among older women can be explained by obstetric complications. DESIGN: A retrospective analysis of routinely collected data from the Aberdeen Maternity and Neonatal Databank. PARTICIPANTS: All residents of Aberdeen city district delivering singleton infants at the Maternity Hospital 1988-1997 (28,484 deliveries). MAIN OUTCOME MEASURES: Odds ratios for each intervention in older maternal age groups compared with women aged 20-29. Interventions considered include obstetric interventions (induction of labour, augmentation, epidural use, assisted delivery, caesarean section) and raised maternity service use (more than two prenatal scans, amniocentesis, antenatal admission to hospital, admission at delivery of more than five days, infant resuscitation, and admission to the neonatal unit). METHODS: Logistic regression was used to investigate the association between maternal age and the incidence of interventions. The odds ratios for each intervention were then adjusted for relevant obstetric complications and maternal socio-demographic characteristics. RESULTS: Levels of amniocentesis, caesarean section, assisted delivery, induction, and augmentation (in primiparae) are all higher among older women. Maternity service use also increases significantly with age: older women are more likely to have an antenatal admission, more than two scans, a hospital stay at delivery of more than five days, and have their baby admitted to a neonatal unit. Controlling for relevant obstetric complications reveals several examples of effect modification, but does not eliminate the age effect for most interventions in most groups of women. CONCLUSIONS: Higher levels of intervention among older women are not explained by the obstetric complications we considered.

Adult↗
PubMed2001

Appraised control, coping, and stress in a community sample: a test of the goodness-of-fit hypothesis.

Lazarus and Folkman proposed one of the most comprehensive theories of stress and coping in the psychology literature, but many of their postulates have received little empirical attention, and some of the existing research hasyielded contradictory findings. This longitudinal study sought to clarify the associations among control appraisal, coping, and stress within this theoreticalframework. The theory postulates that coping strategies used tend to match the level of appraised controllability of the stressor (matching hypothesis). It further states that the effects of problem-focused versus emotion-focused coping are moderated by the appraised controllability of the stressor (goodness-of-fit hypothesis). An alternative to the latter is the main-effects hypothesis, which states that problem-focused coping is generally more effective in reducing distress regardless of appraisal. These hypotheses were tested on 72 adults who completed questionnaires on coping and control appraisal. Stress was assessed using self-report (Symptom Checklist-90-Revised) and a behavioral measure (proofreading task) at two times approximately 2 months apart. Appraised control significantly predicted type of coping such that greater control was associated with more problem-focused and less emotion-focused coping. Although the main-effects hypothesis was not supported, the goodness-of-fit hypothesis was partly confirmed by a significant control by emotion-focused coping interaction predicting both self-report and behavioral measures of stress.

Adaptation, Psychological↗
PubMed2000

Diet in late pregnancy and glucose-insulin metabolism of the offspring 40 years later.

OBJECTIVE: To determine how diets of women in pregnancy influence the glucose-insulin metabolism of their offspring in adult life. DESIGN: A follow up study of men and women born during 1948-1954 whose mothers had taken part in a survey of diet in late pregnancy. SETTING: Aberdeen, Scotland. POPULATION: One hundred and sixty-eight men and women born in the Aberdeen Maternity Hospital. MAIN OUTCOME MEASURE: Plasma glucose and insulin concentrations, fasting and after a standard oral glucose challenge. RESULTS: The offspring of women who had high intakes of fat and protein in late pregnancy had a reduced plasma insulin increment between fasting and 30 min with a 7.0% decrease in increment (P = 0.007) per 10 g increase in protein intake and a 4.9% decrease (P = 0.002) per 10 g increase in fat intake. This was independent of the mother's body mass index or weight gain in pregnancy. A low maternal body mass index in early or late pregnancy was associated with a raised fasting plasma insulin concentration with a decrease of 2.4% (P = 0.05) per 1 kg/m2 increase of maternal body mass. CONCLUSION: High intakes of protein and fat during pregnancy may impair development of the fetal pancreatic beta cells and lead to insulin deficiency in the offspring. The offspring of thin mothers tend to be insulin resistant.

Adult↗
PubMed2000

The effect of smoking on pre-eclampsia in twin pregnancy.

OBJECTIVE: To assess the effect of smoking on the incidence of pre-eclampsia and on perinatal outcome in twin pregnancy. DESIGN: Retrospective study using Aberdeen Maternity and Neonatal Databank. SETTING: Grampian, Orkney and Shetland. POPULATION: All 1,575 twin pregnancies delivered in the years 1969-1971 and 1976-1997 (when smoking data were available). METHODS: In all twin pregnancies the effects of smoking on pre-eclampsia were analysed by parity and gestation at delivery. The effect of smoking upon late miscarriage and perinatal outcome was analysed without subdivision. MAIN OUTCOME MEASURES: Pre-eclampsia and perinatal outcome. RESULTS: Primiparae had significantly higher rates of pre-eclampsia than multiparae and were delivered significantly earlier. The incidence of pre-eclampsia in smokers was significantly lower only in multiparae. Length of gestation was significantly shorter in multiparous smokers. The effect of smoking on pre-eclampsia appeared to be direct in multiparae but possibly indirect in primiparae (by causing earlier delivery). Smokers had a higher late miscarriage rate than nonsmokers. CONCLUSIONS: In twin pregnancy the apparent protective effect of smoking against pre-eclampsia is significant only in multiparae, suggesting that in primiparae the smoking effect is overwhelmed by the other reasons for the development of pre-eclampsia. Smoking in twin pregnancy is not recommended due to the worse fetal outcome rates.

Female↗
PubMed2000

Criteria for clinical audit of the quality of hospital-based obstetric care in developing countries.

Improving the quality of obstetric care is an urgent priority in developing countries, where maternal mortality remains high. The feasibility of criterion-based clinical audit of the assessment and management of five major obstetric complications is being studied in Ghana and Jamaica. In order to establish case definitions and clinical audit criteria, a systematic review of the literature was followed by three expert panel meetings. A modified nominal group technique was used to develop consensus among experts on a final set of case definitions and criteria. Five main obstetric complications were selected and definitions were agreed. The literature review led to the identification of 67 criteria, and the panel meetings resulted in the modification and approval of 37 of these for the next stage of audit. Criterion-based audit, which has been devised and tested primarily in industrialized countries, can be adapted and applied where resources are poorer. The selection of audit criteria for such settings requires local expert opinion to be considered in addition to research evidence, so as to ensure that the criteria are realistic in relation to conditions in the field. Practical methods for achieving this are described in the present paper.

Developing Countries↗
PubMed1999

An investigation of women's involvement in the decision to deliver by caesarean section.

OBJECTIVE: To assess the degree and nature of women's involvement in the decision to deliver by caesarean section, and women's satisfaction with this involvement. DESIGN: Observational study. SETTING: The maternity unit in a large teaching hospital. SAMPLE: One hundred and sixty-six women undergoing caesarean section. METHODS: Interviews with the women on the third or fourth day postpartum, questionnaires sent to the women at 6 weeks and at 12 weeks postpartum, and extraction of information from the women's medical records. MAIN OUTCOME MEASURES: Women's knowledge, satisfaction, and involvement in making the decision concerning their caesarean section. RESULTS: The majority of the women were satisfied with the information they received during pregnancy on caesarean section and with their involvement in making the decision, but the proportions were significantly higher for elective than emergency sections. For 7% of the women, maternal preference for caesarean section was a direct factor in making the decision. Just over half of the 166 women reported that they were not debriefed on the reasons for their caesarean section before their discharge from hospital. Almost a third of the women undergoing emergency caesarean section expressed negative feelings towards their delivery, compared with 13% of those undergoing elective caesarean sections. CONCLUSION: Women are not a homogeneous group in terms of their requirements for information, nor their desire to be involved in the decision on mode of delivery. Health professionals need to be responsive to this variability and to agree on standards for communicating with women during pregnancy about the possibility of operative delivery and for debriefing women after caesarean section.

Adult↗
PubMed1999

A new bladder allows kinetic venous augmentation with a roller pump.

Augmented venous drainage improves venous return during minimally invasive cardiac surgery. Two systems to augment drainage are common: in one, a centrifugal pump draws blood from the venous site and pumps it into a venous reservoir. In the other, suction is applied directly to a hard-shell venous reservoir. Both systems overcome the high resistance of the venous cannula when gravity alone is insufficient to provide adequate drainage. Both systems also have shortcomings: in the first approach, the centrifugal pump head can entrap large bubbles, reducing flow and requiring pump stoppage to remove them. Air from the venous line also can be broken up by the centrifugal pump into small bubbles that can pass through the pump head. The direct suction system in the second approach cannot use a closed-bag reservoir, and has the potential to introduce air into the arterial line. We have developed a new venous augmentation system for a closed venous reservoir that provides excellent suction control without the potential to introduce air into the arterial line. Our system replaces the centrifugal pump of the first approach with a roller pump controlled by the Better-Bladder, a new device with FDA 510(k) clearance for long-term pumping. The Better-Bladder is a length of medical tubing, processed to form a thin-walled, enlarged bladder that is sealed within a clear rigid housing. It acts as an in-line reservoir that provides compliance in the venous line and a noninvasive means to measure blood pressure at the pump inlet. The bladder housing can maintain a negative pressure set by the user that controls the degree of gravity drainage. Tests have shown that the Better-Bladder allows for safe, smooth pump control using a roller pump in the venous line.

Catheterization, Central Venous↗
PubMed1999

An improved bladder for pump control during ECMO procedures.

A new inline reservoir called the Better-Bladder, now FDA-cleared for long term use, overcomes some disadvantages of the silicone bladder and bladder box used in extracorporeal membrane oxygenation circuits. The Better-Bladder provides compliance in the venous line and allows for noninvasive pressure measurements. Both features are useful for controlling pump speed as a function of venous line pressure. Bench tests showed that the Better-Bladder measures pressure noninvasively within +/- 4% of invasive (i.e., liquid contacting) pressure measurements in a range from -200 to +500 mmHg and at temperatures from 10 degrees C to 37 degrees C. After 60 days, the error in noninvasive pressure measurement with the Better-Bladder was less than +/- 3%. The Better-Bladder withstood pressurization to 1700 mmHg for ten days without leaking or failing in other ways. The advantages of the Better Bladder, along with its accuracy and durability, suggest its use for short and long term pumping applications.

Bias↗
PubMed1998

Subclavian artery pseudoaneurysm in type IV Ehlers-Danlos syndrome.

We report case of a subclavian artery pseudoaneurysm in a patient with type IV Ehlers-Danlos Syndrome. A 16-year-old boy underwent successful repair of a subclavian artery pseudoaneurysm that occurred after a cervical hyperextension injury. Subsequent workup included skin biopsy and fibroblast culture, which were consistent with a diagnosis of type IV Ehlers-Danlos Syndrome. This condition is a dominantly inherited connective tissue disorder, which in this patient was found to be caused by a spontaneous point mutation in the COL3A1 gene that encodes the chains of type III procollagen. The clinical, genetic, and molecular characteristics of type IV Ehlers-Danlos Syndrome are briefly reviewed.

Adolescent↗
PubMed1997

Successful minimally invasive triple coronary bypass through bilateral parasternal incisions.

A 58-year-old man with left main and right coronary artery disease requiring preoperative intraaortic balloon pumping underwent successful minimally invasive triple coronary bypass through bilateral parasternal incisions. Despite taking immunosuppressive drugs because of a previous liver transplantation, the patient had all-arterial grafts without sternotomy. He was discharged on the fourth postoperative day, returned to work in 4 weeks, and has a negative thallium stress test.

Coronary Artery Bypass↗
PubMed1996

Long-term outcome by method of delivery of fetuses in breech presentation at term: population based follow up.

OBJECTIVE: To compare the long-term outcome of infants delivered in breech presentation at term by intended mode of delivery. DESIGN: A population based comparison of outcomes up to school age. Data obtained from maternity, health visitor, and school medical records and handicap register. SETTING: Grampian region 1981-90. SUBJECTS: 1645 infants delivered alive at term after breech presentation. MAIN OUTCOME MEASURES: Handicap, developmental delay, neurological deficit, psychiatric referral. RESULTS: Elective caesarean section was performed in 590 (35.9%) cases. The remainder (1055; 64.1%) were intended vaginal deliveries. Handicap or other health problem was recorded in 269 (19.4%) of 1387 infants for whom records were available. Proportions of elective caesarean sections and intended vaginal deliveries in this group were 37.2% (100 cases) and 62.8% (169) respectively, almost the same as in the total cohort. There were no significant differences between elective caesarean section and planned vaginal delivery in terms of severe handicap or any other outcome measure. Case records were obtained for 23 of 27 infants with severe handicap. 11 (47.8%) were delivered by elective caesarean section. Of these, three had undiagnosed congenital abnormalities and seven were unexplained. Of the 12 (52.2%) planned vaginal deliveries, in only one was handicap possibly attributable to delivery and four cases were unavoidable even if elective caesarean section had been planned. CONCLUSION: In selected cases of breech presentation at term planned vaginal delivery with caesarean section if necessary remains as safe as elective caesarean section in terms of long term handicap. It was not possible to determine whether particular babies would have fared better had they been delivered by elective caesarean section.

Birth Weight↗