Pregnancy and lactation have no long-term deleterious effect on measures of bone mineral in healthy women: a twin study

BACKGROUND: The long-term effects of pregnancy and lactation on measures of bone mineral in women remain unclear.

OBJECTIVE: We studied whether pregnancy or lactation has deleterious long-term effects on bone mineral in healthy women.

DESIGN: We measured bone mineral density (BMD; g/cm(2)) in women aged > or = 18 y. Analyses were performed on 3 data sets: study 1, 83 female twin pairs (21 monozygous and 62 dizygous) aged (x +/- SD) 42.2 +/- 15.5 y who were discordant for ever having been pregnant beyond 20 wk; study 2, 498 twin pairs aged 42.3 +/- 15.0 y; and study 3, 1354 individual twins, their siblings, and family members.

RESULTS: In study 1, there were no significant within-pair differences in unadjusted BMD or BMD adjusted for age, height, and fat mass at the lumbar spine or total-hip or in total-body bone mineral content (BMC; kg) (paired t tests). In study 2, there was no significant within-pair difference in measures of bone mineral or body composition related to the within-pair difference in number of pregnancies. In study 3, subjects with 1 or 2 (n = 455) and > or = 3 pregnancies (n = 473) had higher adjusted lumbar spine BMD (2.9% and 3.8%, respectively; P = 0.001) and total-body BMC (2.2% and 3.1%; P < 0.001) than did nulliparous women (n = 426). Parous women who breast-fed had higher adjusted total-body BMC (2.6%; P = 0.005), total-hip BMD (3.2%; P = 0.04), and lower fat mass (10.9%; P = 0.01) than did parous non-breast-feeders.

CONCLUSION: We found no long-term detrimental effect of pregnancy or breast-feeding on bone mineral measures.

Finding a 'safe' place on the risk continuum: a case study of pregnancy and birthing in Lao PDR (Lao People's Democratic Republic)

This paper addresses two questions. Firstly: are the risk regimes faced, and perceived, by pregnant women in rural Lao PDR substantially different from those experienced by pregnant women in western societies? Secondly, if the Lao experiences and perceptions are different, can improvements in maternal health in Lao PDR be achieved without Laotians inheriting the risk regimes of late modernity experienced by many women in western societies? Secondary analysis is undertaken of data collected in 2005 for the evaluation of a pilot maternity waiting home in Bolikhan, Lao PDR. The results suggest significantly different risk perceptions and experiences between Lao and western communities, based on contrasting views of embodiment, identity construction and cosmologies. In the Lao rural communities studied, there is little evidence yet of 'risk society' despite the introduction of western technologies and practices to improve maternal mortality and morbidity. It is argued that 'risk society' can be avoided.

Determinants of bone density in 30- to 65-year-old women: A co-twin study

Introduction: Reported effects of body composition and lifestyle of bone mineral density in pre-elderly adult women have been inconsistent.

Methods: In a co-twin study of 146 female twin pairs aged 30 to 65 years, DXA was used to measure bone mineral density at the lumbar spine, total hip, and forearm, total body bone mineral content, and lean and fat mass. Height and weight were measured. Menopausal status, dietary calcium intake, physical activity, current tobacco use, and alcohol consumption were determined by questionnaire. Within-pair differences in bone measures were regressed through the origin against within-pair differences in putative determinants.

Results: Lean mass and fat mass were associated with greater bone mass at all sites. A discordance of 10 pack-years smoking was related to a 2.3-3.3% (SE, 0.8-1.0) decrease in bone density at all sites except the forearm, with the effects more evident in postmenopausal women. In all women, a 0.8% (SE, 0.3) difference in hip bone mineral density was associated with each hour per week difference in sporting activity, with effects more evident in premenopausal women. Daily dietary calcium intake was related to total body bone mineral content and forearm bone mineral density (1.4 ± 0.7% increase for every 1000 mg). Lifetime alcohol consumption and walking were not consistently related to bone mass.

Conclusion: Several lifestyle and dietary factors, in particular tobacco use, were related to bone mineral density. Effect sizes varied by site. Characterization of determinants of bone mineral density in midlife and thereafter may lead to interventions that could minimize postmenopausal bone loss and reduce osteoporotic fracture risk.

Factors that influence women's disclosures of substance use during pregnancy : a qualitative study of ten midwives and ten pregnant women

The present study was designed to examine the factors that motivate or act as barriers to disclosure of substance use by pregnant women. Participants included 10 midwives and 10 pregnant women who attended two ante-natal clinics at an Australian maternity hospital. One clinic specialized in women who were substance users and one clinic was specifically for young women (under 19 years of age). Midwives and pregnant women were interviewed in-depth about disclosure of substance use. Interview transcripts were analyzed, and the results revealed six main themes: practice style, assessment of substance use, practice environment and privacy, child protection issues, health of the baby, and continuity of care. The findings are discussed in relation to recommendations for best practice in midwifery care when working with pregnant women who use substances.

Thats classified: class politics and adolescence in twin peaks

Twin Peaks arguably paved the way for the television programmes currently popular with adolescent audiences, like The OC and Veronica Mars and, in it, many of the issues and representational strategies in those later programmes have their earlier manifestation. Specifically, the Twin Peaks plotline evinces a set of cultural anxieties about class-difference. Twin Peaks creates a cultural microcosm of American society that is paradoxically writ large by the limited parameters of an isolated community. Within a constricted space, characters are depicted as both individuals and as archetypes of a class location.

The effect of calcium supplementation on bone density in premenarcheal females: a co-twin approach

The age and developmental stage at which calcium supplementation produces the greatest bone effects remain controversial. We tested the hypothesis that calcium supplementation may improve bone accrual in premenarcheal females. Fifty-one pairs of premenarcheal female twins (27 monozygotic and 24 dizygotic; mean ± SD age, 10.3 ± 1.5 yr) participated in a randomized, single-blind, placebo-controlled trial with one twin of each pair receiving a 1200-mg calcium carbonate (Caltrate) supplement. Areal bone mineral density (aBMD) was measured at baseline and 6, 12, 18 and 24 months. There were no within-pair differences in height, weight, or calcium intake at baseline. Calcium supplementation was associated (P < 0.05) with increased aBMD compared with placebo, adjusted for age, height, and weight at the following time points from baseline: total hip, 6 months (1.9%), 12 months (1.6%), and 18 months (2.4%); lumbar spine, 12 months (1.0%); femoral neck, 6 months (1.9%). Adjusted total body bone mineral content was higher in the calcium group at 6 months (2.0%), 12 months (2.5%), 18 months (4.6%), and 24 months (3.7%), respectively (all P < 0.001). Calcium supplementation was effective in increasing aBMD at regional sites over the first 12–18 months, but these gains were not maintained to 24 months.

Smoking cessation programs in pregnancy: systematically addressing development, implementation, women's concerns and effectiveness

Objectives:  To increase a review's relevance to practitioners and service users and identify the implications for systematic review methodology. Methods:  A systematic review of the effects of smoking cessation programmes implemented during pregnancy integrated process indicators and the views of maternity service users and health promotion specialists. Additional qualitative data were extracted systematically from included randomised control trials (RCTs) to determine whether the design of interventions and conclusions arising from their evaluation related to the views of service users. On completing the review we reflected on the types of observational and qualitative research it drew on, where this research was incorporated into the review, and its added value. Results:   Incorporating process indicators into the review revealed: 1) problems with implementation and transplantation of some interventions and 2) studies with more stringent quality criteria and process evaluations demonstrated greater impact (weighted mean difference in smoking). Pregnant smokers were rarely involved in the design or evaluation of the interventions. Prior observational and qualitative studies and small scale consultations influenced the criteria by which the effectiveness of the interventions were judged, and revealed to what extent these criteria are adopted in practice.
Conclusions:   Systematically abstracting data about the development and delivery of interventions revealed gaps that might be filled by the active involvement of service users.

How well do women adapt to changes in their body size and shape across the course of pregnancy

This study examined body image across pregnancy. Pregnant women ( N = 158) completed measures of general attractiveness, feeling fat, fitness and strength, salience of weight and shape, and ideal and current body size at pre-pregnancy (retrospective), and in early, middle and late pregnancy. Body image was found to be fairly stable across pregnancy such that women who started with greater body concerns maintained them over time. Although women were least satisfied with their stomach size at late pregnancy, women's ideal body shape increased in parallel with increases in body size. Women with the most body concerns reported more depressive symptoms, tendency towards dieting, and smoking during pregnancy suggesting they were at greater risk in terms of health and well-being during pregnancy.

Use of complementary and alternative medicines by a sample of Australian women during pregnancy

Background: The use of complementary and alternative medicines (CAM) is growing in Australia, with women higher users than men. Yet, only a few Australian studies have explored the use of CAM during pregnancy.

Aims: To explore the use of CAM, the types of CAM practitioners consulted, physical symptoms/complaints for which CAM are used by a sample of pregnant Australian women, and women's perceptions of the efficacy of CAM in treating those complaints.

Methods: Three hundred and twenty-one pregnant women, who volunteered for a study exploring women's well-being during pregnancy, completed a self-report questionnaire in their late second/early third trimester.

Results: Seventy-three per cent of women had used at least one kind of complementary therapy in the prior eight weeks of pregnancy. Over one-third of the women had visited at least one alternative medicine practitioner during pregnancy. Approximately one-third of the women reported taking CAM to alleviate a specific physical symptom, with 95.7% of these women reporting they either got completely better or a little bit better with use of CAM; one quarter reported planning to use an alternative therapy to assist with labour preparation. Age, number of physical symptoms experienced, income level and level of education were not associated with greater use of CAM (P < 0.05); however, women reporting more physical symptoms were more likely to consult a CAM practitioner.

Conclusion: Findings highlight the substantial use of CAM during pregnancy and the need to have all health professionals adequately informed about such therapies during this life stage.

Sleep quality and depression during pregnancy: a prospective study

For the first time, the relationship between depressive symptoms and sleep quality was explored prospectively during pregnancy. Participants (n = 273) completed the Pittsburgh Sleep Quality Index and Beck Depression Inventory at three 8-week intervals, starting from 15–23 weeks gestation. In addition to sleep quality and depression remaining relatively stable during pregnancy, findings revealed that sleep quality earlier in pregnancy predicted higher levels of depressive symptoms at later stage in pregnancy (after controlling for prior depression levels). In contrast, there was no evidence to suggest that depressive symptoms earlier in pregnancy impacted on sleep quality later on. Given that depressive symptomatology can lead to major depression and given the prevalence of pre- and postnatal depression, our findings suggest that screening for sleep problems during pregnancy may be of clinical significance.

Identification and rationalization of secondary twin variants in a magnesium alloy

The present work combines electron backscatter diffraction, transmission electron microscopy and Schmid analysis to investigate secondary twinning in the magnesium alloy Mg-3AI-1Zn. Inspection of the misorientations between the parent matrix and {1011} - {1012} doubly twinned volumes reveals that there are four possible variants. One of these variants characterized by 38°< 1210 > misorientation with the matrix is favoured much more than the others. This variant involves activation of the secondary twinning systems that are quite inconsistent with the Schmid-type behaviour. For the secondary twin to grow significantly it must take on a shape enforced by the primary twin, however, this is not optimal for strain compatibility. It is argued that the 38° < 1210 > variant occurs most frequently because it provides the closest match between the primary and secondaty twinning planes, thus minimizing the compatibility strain. This conjecture is confirmed by the simulations of twin activity m ellipsoidal grains performed using the visco-plastic self-consistent crystal plasticity model.