Emily K. Rousham

Significant changes in physical activity among pregnant women in the UK as assessed by accelerometry and self-reported activity

Objective:Research on the impact of maternal physical activity on pregnancy outcomes has often employed subjective measures of physical activity obtained by diary or questionnaire. This study investigates the feasibility of using accelerometry as an objective measure of physical activity of pregnant women compared with subjective data obtained via activity recall among pregnant women.Design:Activity data were collected prospectively on 57 women at 12, 16, 25, 34 and 38 weeks of gestation. Total daily physical activity was assessed by ambulatory accelerometer and activity interview (self-report). Maternal personality variables (health value, extroversion) were assessed by established scales.Setting:Leicestershire, UK.Subjects:Pregnant women were recruited by voluntary participation via antenatal booking clinics. In all, 64 pregnant women with low-risk pregnancy were enrolled onto the study, of whom 57 completed the study.Results:Mean 24 h physical activity levels (PAL) decreased significantly from second to third trimester as assessed by self-report interview (1.51–1.29 Metabolic Equivalent TEE-h/day, P<0.01) and accelerometry (200.05–147.42 counts/min, P<0.01). The correlation between the two measures declined as pregnancy progressed (r value ranging from 0.55 to 0.08). Compliance with the accelerometers declined from 90% at 12 weeks to 47% at 34 weeks (P<0.01). Compliance with the self-report interviews was 100%. Those who fully complied with the accelerometry demonstrated a significantly higher health value (P<0.05) and a significantly greater level of extroversion (P<0.05) than those who did not.Conclusions:Accelerometers and self-reported activity interviews both indicated a significant decline in PAL during pregnancy. Although subjects showed a willingness to use both methods, accelerometers resulted in variable compliance with 72 h monitoring. Both techniques may be limited by the need to measure low levels of physical activity during the third trimester.Sponsorship:Cambridge Neurotechnology Ltd, UK, assisted with the provision of Actiwatch accelerometers.

Guidelines for Physical Activity During Pregnancy Comparisons From Around the World

Introduction. Women attain numerous benefits from physical activity during pregnancy. However, because of physical changes that occur during pregnancy, special precautions are also needed. This review summarizes current guidelines for physical activity among pregnant women worldwide. Methods. We searched PubMed (MedLINE) for country-specific governmental and clinical guidelines on physical activity during pregnancy through the year 2012. We cross-referenced with articles referring to guidelines, with only the most recent included. An abstraction form was used to extract key details and summarize. Results. In total, 11 guidelines were identified from 9 countries (Australia, Canada, Denmark, France, Japan, Norway, Spain, United Kingdom, United States). Most guidelines supported moderate-intensity physical activity during pregnancy (10/11) and indicated specific frequency (9/11) and duration/time (9/11) recommendations. Most guidelines provided advice on initiating an exercise program during pregnancy (10/11). Six guidelines included absolute and relative contraindications to exercise. All guidelines generally ruled-out sports with risks of falls, trauma, or collisions. Six guidelines included indications for stopping exercise during pregnancy. Conclusion. This review contrasted pregnancy-related physical activity guidelines from around the world, and can help inform new guidelines as they are created or updated and facilitate the development of a worldwide guideline.

Activity patterns and time allocation during pregnancy: a longitudinal study of British women.

Objective: Few studies provide data regarding the integrated everyday activities of Western pregnant women. The study aimed to quantify changes in the daily activity of women during pregnancy and to examine whether pregnancy has a differential impact on different activity domains. Design: A prospective, longitudinal study of maternal time allocation and activity was carried out. Methods: The time allocation patterns of 57 healthy nulliparous pregnant women were assessed at 16, 25, 34 and 38 weeks gestation by semi-structured interview. Mean total daily activity levels (DALs) were estimated according to the intensity and duration of each activity reported. Self-reported activity was sub-divided into occupational, recreational, domestic and nocturnal activity ratios. Results: From 16 to 34 weeks gestation mean self-reported DAL declined significantly from 1.54 to 1.40 METS (Metabolic Equivalent TEE Score, where TEE is total energy expenditure) (p < 0.001). In the different activity domains, mean occupational activity ratio decreased (p < 0.002) whilst nocturnal activity ratio increased (p < 0.002) from 16 to 34 weeks. Mean recreational activity ratio decreased significantly between 25 and 38 weeks (p < 0.001) but no significant changes were observed in mean domestic activity ratio. Conclusions: Low-risk pregnancy has a differential impact on occupational, recreational and domestic domains. Economies in energy expenditure appear to be made in occupational and recreational activity while domestic activities are largely maintained during pregnancy. Changes in physical activity may be influenced more by the type of activity rather than the intensity of activity.

Maternal reports of child illness and the biochemical status of the child: the use of morbidity interviews in rural Bangladesh

In a longitudinal study of child growth and nutritional status in Bangladesh, child morbidity was recorded using health interviews with the mother. The aim of the present study was to establish whether maternal reports of child illness were associated with the biochemical health status of the child. Children aged 2-5 years (n 117) took part in the study and their mothers were interviewed every fortnight by Bangladeshi fieldworkers. Maternal reports of diarrhoea were associated with significantly lower plasma albumin concentrations (P < 0.001), poorer intestinal permeability (P < 0.001), higher plasma immunoglobulin A levels (P < 0.005) and higher alpha-1-antichymotrypsin (ACT) levels (P < 0.05) compared with children reported to be healthy. Children with fever had significantly higher ACT (P < 0.001) and lower albumin (P < 0.05) levels compared with their healthy counterparts. Respiratory infections (RI) were not associated with any significant changes; however, reports of RI with fever were associated with significantly higher levels of ACT than either illness individually (interaction P < 0.05). These highly significant associations between maternal reports of illness and biochemical profiles of child health support the use of health interviews in developing countries.

Secular trends in skeletal maturity in South Africa: 1962–2001

Background: Secular trends are usually monitored through changes in size and earlier maturation. Skeletal maturity has rarely been used as a biological indicator of secular trend. Aim: To observe secular changes in the skeletal maturity of urban South African adolescents between 1962 and 2001. Subjects and methods: Data from the Pretoria National Nutrition Survey were compared with a cross-sectional survey of children from the Johannesburg–Soweto based Birth to Twenty birth cohort study. Adolescents aged 9–11 years from each survey were included in the analysis. Skeletal maturity was assessed using the Greulich–Pyle technique. Height, weight, triceps and subscapular skinfolds were also measured. Results: The skeletal maturity of white males and females in 2001 was in advance of the 1962 cohort by an average of 3.4 months and 2.0 months, respectively. Black males and females in 2001 were significantly in advance of the 1962 cohort by an average of 9.7 months and 15.8 months, respectively (p<0.01). Conclusion: Significant secular increases in the skeletal maturity of urban black South African children occurred between 1962 and 2001. Non-significant increases were seen in white children. The significant secular increases were concordant with increases in stature and adiposity during this period. The increase in skeletal maturity may reflect the removal of growth constraint, particularly in black children.

Socio-economic status and body composition outcomes in urban South African children

Objective: To determine which aspects of socio-economic status (SES) measured at birth and at ages 9 or 10 years, are associated with body composition at ages 9 or 10 years. Design: Mixed longitudinal cohort. Setting: Johannesburg-Soweto South Africa. Participants: A sub-sample of the Birth to Twenty (Bt20) cohort (n = 281) with data on birth weight, height, weight, fat and lean tissue (whole body dual-energy x ray absorptiometry (DXA)), and birth and ages 9 or 10 years SES measures. Main outcome measures: Linear regression was used to estimate the influence of birth and ages 9 or 10 years SES measures on three outcomes: fat mass index (FMI) (fat mass (kg)/height (m)4), lean mass index (LMI) (lean mass (kg)/height (m)2), and body mass index (BMI) at ages 9 or 10 years controlling for sex, age, birth weight and pubertal status. Results: Compared to the lowest SES tertile, being in the highest birth SES tertile was associated with increased LMI at ages 9 or 10 years (β = 0.43, SE = 0.21 for white and black children and β = 0.50, SE = 0.23 for black children only), whereas children in the high SES tertile at ages 9 or 10 years had increased FMI (β = 0.46, SE = 0.22 for white and black children, and β = 0.65, SE = 0.23 for black children only). SES at birth and at ages 9 or 10 years accounted for 8% and 6% of the variance in FMI and BMI, respectively (black children). Conclusions: These findings underline the importance of examining SES across childhood ages when assessing nutrition inequalities. Results emphasise the need to consider lean and fat mass as well as BMI when studying SES and body composition in children.

Ethnic and sex differences in skeletal maturation among the Birth to Twenty cohort in South Africa

Aim To examine ethnic and sex differences in the pattern of skeletal maturity from adolescence to adulthood using a novel longitudinal analysis technique (SuperImposition by Translation And Rotation (SITAR)). Setting Johannesburg, South Africa. Participants 607 boys and girls of black as well as white ethnicity from the Birth to Twenty bone health study, assessed annually from 9 to 20 years of age. Outcome measure Bone maturity scores (Tanner–Whitehouse III radius, ulna, and short bones (TW3 RUS)) assessed longitudinally from hand-wrist radiographs were used to produce individual and mean growth curves of bone maturity and analysed by the SITAR method. Results The longitudinal analysis showed that black boys matured later by 7.0 SE 1.6 months (p<0.0001) but at the same rate as white boys, whereas black girls matured at the same age but at a faster rate than white girls (by 8.7% SE 2.6%, p=0.0007). The mean curves for bone maturity score consistently showed a midpubertal double kink, contrasting with the quadratic shape of the commonly used reference centile curves for bone maturity (TW3). Conclusions Skeletal maturity was reached 1.9 years earlier in girls than boys, and the pattern of maturation differed between the sexes. Within girls, there were no ethnic differences in the pattern or timing of skeletal maturity. Within boys, however, skeletal maturity was delayed by 7 months in black compared with white ethnicity. Skeletal maturation, therefore, varies differentially by sex and ethnicity. The delayed maturity of black boys, but not black girls, supports the hypothesis that boys have greater sensitivity to environmental constraints than girls.

Factors affecting birthweight of rural Australian Aborigines

Aim : To examine factors affecting birthweight of Aboriginal infants in the Kimberley region of north-west Australia. Research design : A retrospective study of maternal and infant health records obtained through routine data collection. Subjects and methods : Birthweight and length of 2959 infants born to 1822 women from 1986 to 1994 were analysed. Mothers and infants were matched using unique identification codes. Index births and subsequent births to the same mother were collated in order to examine relative birth order effects and to calculate birth intervals. Results : Regression analysis showed significant associations between weight of the index birth and maternal age ( p < 0.001), remoteness of locality ( p < 0.01), sex of the infant ( p < 0.001) and maternal height ( p < 0.001). Length at birth was significantly associated with ethnicity of infant (Aboriginal vs Aboriginal/non-Aboriginal admixture, p < 0.05), sex ( p < 0.001), remoteness ( p < 0.01) and maternal height ( p < 0.001). Similar associations were observed for second and subsequent births. Birth interval was not associated with birthweight or length. Low birthweight was also more common to Aboriginal mothers compared with mothers of Aboriginal/non-Aboriginal admixture (13.1% vs 9.2%; h 2 = 5.1, p < 0.025) even though there were no differences in height between these two groups. Teenage mothers ( r 19 years) were no more likely to have low birthweight babies than older mothers. Of the variables examined, the only significant predictor of low birthweight was a previous low birthweight baby (relative risk = 4.45, p < 0.001). Conclusions : Short birth intervals and teenage births were not significant contributors to low birthweight in the present study. The high prevalence and duration of breastfeeding in the Kimberley may contribute to long average birth intervals. Pre-term birth, rather than intrauterine growth retardation, is likely to be the most common cause of low birthweight in this population.

Persistent growth faltering among Aboriginal infants and young children in north-west Australia: a retrospective study from 1969 to 1993

The objective was to examine long‐term changes in the growth of Aboriginal infants and young children in the Kimberley region in the far northwest of Australia from 1969 to 1993. A retrospective analysis of anthropometric data (weight and length) routinely collected on 0–5‐year‐old children in 5‐year cohorts from 1969 to 1993 was carried out. From 1974‐78 to 1989‐93 there has been a significant increase in mean birthweight (ANOVA p < 0.05). The percentage of low birthweight infants (<2500g) declined from 14% in 197983 to 10% in 1989‐93 (p < 0.001). There were no consistent improvements in the growth patterns of infants from birth to 60 months. All cohorts displayed pronounced growth faltering in weightforage and heightforage from 6 to 12 months of age and fell significantly below both the NCHS reference values and mean values for healthy breastfed infants. In conclusion, reductions in Aboriginal infant mortality and infectious disease rates over the past 20 years have not been accompanied by improved growth. The persistence of child malnutrition in these communities may warrant a shift in attention from disease treatment and prevention to a better understanding of nutritional influences, particularly weaning practices, during infancy and early childhood.

Summary of international guidelines for physical activity after pregnancy.

Postpartum physical activity can improve mood, maintain cardiorespiratory fitness, improve weight control, promote weight loss, and reduce depression and anxiety. This review summarizes current guidelines for postpartum physical activity worldwide. PubMed (MEDLINE) was searched for country-specific government and clinical guidelines on physical activity after pregnancy through the year 2013. Only the most recent guideline was included in the review. An abstraction form facilitated extraction of key details and helped to summarize results. Six guidelines were identified from 5 countries (Australia, Canada, Norway, United Kingdom, and United States). All guidelines were embedded within pregnancy-related physical activity recommendations. All provided physical activity advice related to breastfeeding and 3 remarked about physical activity after cesarean delivery. Recommended physical activities mentioned in the guidelines included aerobic (3/6), pelvic floor exercise (3/6), strengthening (2/6), stretching (2/6), and walking (2/6). None of the guidelines discussed sedentary behavior. The guidelines that were identified lacked specificity for physical activity. Greater clarity in guidelines would be more useful to both practitioners and the women they serve. Postpartum physical activity guidelines have the potential to assist women to initiate or resume physical activity after childbirth so that they can transition to meeting recommended levels of physical activity. Health care providers have a critical role in encouraging women to be active at this time, and the availability of more explicit guidelines may assist them to routinely include physical activity advice in their postpartum care. Target Audience Obstetricians and gynecologists, family physicians Learning Objectives After completing this CME activity, physicians should be better able to describe the benefits of physical activity identified in postpartum physical activity guidelines, discuss the impacts of physical activity on breastfeeding as described in postpartum physical activity guidelines, and assess the limitations of the current postpartum physical activity guidelines.