Validity of the SenseWear® Armband to Predict Energy Expenditure in Pregnant Women

Energy expenditure in healthy pregnant women: a systematic review

CONTEXT

Since pregnancy is a decisive period for women and children in terms of future health, it is very important to determine changes in energy expenditure and requirements. However, there is no reference method to determine the energy expenditure as there are many factors that change maternal energy homeostasis during this period.

OBJECTIVE

This review aims to evaluate the changes in energy expenditure during pregnancy and the effects of these changes on maternal weight gain, as well as the methods used to determine energy expenditure.

DATA SOURCES

Google Scholar, PubMed, ScienceDirect, Cochrane Library, and Wiley Online Library databases were searched to determine studies on energy expenditure during pregnancy between 2010 and 2022.

DATA EXTRACTION

Of the 2095 articles initially identified, 20 met the inclusion criteria for this review. Two independent reviewers selected and extracted data from those articles.

DATA ANALYSIS

The articles reviewed show that prepregnancy body mass index, gestational weight gain, changes in fat mass, and lean body mass influence energy expenditure during pregnancy. Doubly-labeled water and indirect calorimetric methods are considered reference methods for determining energy expenditure in pregnancy. Indirect calorimetric methods, when used together with body weight and physical activity measurements, allow an accurate estimation of resting energy expenditure and energy requirements for pregnant women. Metabolic Holter or accelerometers are valid methods for determining activity energy expenditure in pregnant women and are suitable for use during activity.

CONCLUSION

Resting energy expenditure and activity energy expenditure should be carefully monitored and measured by valid methods to achieve the correct energy intake targets during pregnancy. The existing equations used in determining energy expenditure should be developed for a more accurate estimation of energy expenditure during pregnancy, or new pregnancy-specific equations should be derived.

Effects of a behavioral intervention on physical activity, diet, and health-related quality of life in postpartum women with elevated weight: results of the HIPP randomized controlled trial

BACKGROUND

Approaches to improve physical activity (PA), diet, and health-related quality of life (HRQOL) during postpartum in diverse women with elevated weight are needed.

METHODS

Health In Pregnancy and Postpartum (HIPP) was a randomized controlled trial that followed African American and white women with overweight or obesity from pregnancy through 12 months postpartum. Participants were randomized to a behavioral intervention grounded in social cognitive theory (n = 112) or standard care (n = 107). From enrollment (≤ 18 weeks gestation) through 6 months postpartum, the intervention group received two in-depth counseling sessions (one each during pregnancy and postpartum), counseling calls, behavioral podcasts, and access to a private Facebook group, while the standard care group received monthly mailings and podcasts focused on healthy pregnancy and infant development. PA (SenseWear armband), diet (ASA24), and HRQOL (SF-12) measurements were obtained from blinded assessors at baseline and 6- and 12-months postpartum. Linear or quantile regression models, depending on conformity to normality assumptions, were used to test differences between behavioral intervention and standard groups in PA outcomes (minutes/day of total PA, light PA, and moderate-to-vigorous intensity PA (MVPA), and total steps/day), dietary outcomes (diet quality and six measures of dietary intake), and HRQOL at 6- and 12-months postpartum, controlling for baseline values, race, parity, weight status, education, maternal age, gestational age, and caloric intake (for most diet models).

RESULTS

There were no statistically significant differences by group for any PA, diet, or HRQOL outcomes at 6 or 12 months postpartum. Irrespective of group assignment, all PA outcomes improved from pregnancy to postpartum, as did kcals and the mental component of HRQOL. Furthermore, while not statistically significant, virtually all PA outcomes, except MVPA at 12 months, and several dietary outcomes, including diet quality, had patterns favoring the intervention group but with small effect sizes.

CONCLUSIONS

Postpartum PA, diet, and HRQOL did not differ significantly between women in the behavioral intervention group and those in the standard care group. Given the increased responsibilities and stress that women face during the postpartum period, this appears to be a challenging time to make lifestyle changes.

TRIAL REGISTRATION

This trial was registered at ClinicalTrials.gov on 10/09/2014. Identifier: NCT02260518.

Association Between Physical Activity During Pregnancy and Perinatal Depressive Symptoms in Pregnant Individuals With Overweight and Obesity

INTRODUCTION

Current research on the association between physical activity and perinatal depression is inconclusive. This study examined the association between objectively measured physical activity during pregnancy and perinatal depressive symptoms among individuals with overweight and obesity.

METHODS

Data came from the Health in Pregnancy and Postpartum study (N = 205). Physical activity was measured using the SenseWear Armband at 16 weeks' or fewer and 32 weeks' gestation and categorized into 1) never meeting 2018 physical activity guidelines, 2) meeting the guidelines at one time point, or 3) meeting the guidelines at both time points. Antenatal depressive symptoms were assessed at 32 weeks' gestation, and postpartum depressive symptoms were assessed at 6 and 12 months postpartum using the Edinburgh Postnatal Depression Scale. A score of 10 or higher was defined as probable at least minor depression (hereafter, probable depression).

RESULTS

Nearly one-half of the participants (45.4%) met physical activity guidelines both in early and late pregnancy. Pregnant individuals who met physical activity guidelines at one (adjusted odds ratio, 0.07; 95% confidence interval, 0.01-0.76) or both time points (adjusted odds ratio, 0.08; 95% confidence interval, 0.01-0.69) during pregnancy had lower odds of probable depression at 6 months postpartum than individuals who never met physical activity guidelines during pregnancy. No significant associations were found between prenatal physical activity and probable antenatal or postpartum depression at 12 months.

CONCLUSIONS

Antenatal physical activity was associated with lower odds of probable depression at 6 months after childbirth. Physicians should use evidence-based strategies to encourage pregnant people, especially those who are at risk for postpartum depression, to meet physical activity guidelines.

Maternal physical activity affects yolk sac size and growth in early pregnancy, but girls and boys use different strategies

This longitudinal study investigated the impact of actigraphy-measured maternal physical activity on yolk sac size during early development. The yolk sac, a transient extraembryonic organ, plays a crucial role in embryonic development and is involved in metabolism, nutrition, growth, and hematopoiesis. Prospectively collected data from 190 healthy women indicated that their total daily physical activity, including both light and moderate-vigorous activity, was associated with yolk sac growth dynamics depending on embryonic sex and gestational age. Higher preconception maternal physical activity was linked to a larger yolk sac at 7 weeks (95% CI [0.02-0.13 mm]) and a smaller yolk sac at 10 weeks' gestation (95% CI [- 0.18 to - 0.00]) in male embryos; in female embryos, the yolk sac size was increased at 10 weeks' gestation (95% CI [0.06-0.26]) and was, on average, 24% larger than that in male embryos (95% CI [0.12-0.38]). Considering the pattern of other maternal effects on yolk sac size-e.g., body composition and sleep duration-we suggest that physiological yolk sac adaptations occur in short, sex-specific time windows and can be influenced by various maternal factors.

Take it to the limit: The limitations of energetic explanations for birth timing in humans

A hallmark of modern humans is that our newborns are neurologically immature compared to other primates. It is disputed whether this so-called secondary altriciality evolved due to remodelling of the pelvis associated with bipedal locomotion, as suggested by the obstetrical dilemma hypothesis, or from maternal energetic limitations during pregnancy. Specifically, the 'Energetics of Gestation and Growth' (EGG) hypothesis posits that birth is initiated when foetal energy requirements exceed the maximum sustained maternal metabolic rate during pregnancy at around 2.1 × basal metabolic rate (BMR) of the non-pregnant, non-lactating condition (NPNL). However, the metabolic threshold argued under the EGG framework is derived from one study with a small sample size of only 12 women from the UK. Accordingly, we performed a meta-analysis of all published studies on metabolic scopes during pregnancy to better account for variability. After excluding 3 studies with methodological issues, a total of 12 studies with 303 women from 5 high- and 3 low-income countries were analysed. On average, pregnancy was found to be less metabolically challenging than previously suggested. The studies revealed substantial variation in metabolic scope during pregnancy, which was not reflected by variation in birth timing. Further, in a third of the studies, the metabolic rates exceeded 2.1 × BMRNPNL. Our simulation of foetal energy requirements demonstrated that this metabolic threshold of 2.1 × BMRNPNL cannot realistically be crossed by the foetus around the time of birth. These findings imply that metabolic constraints are not the main limiting factor dictating gestation length.

Comparative Assessment of Diet Quality and Adherence to a Structured Nutrition and Exercise Intervention Compared with Usual Care in Pregnancy in a Randomized Trial

Background

In trials testing the efficacy of diet and exercise modifications during pregnancy on health outcomes, assessment of participant adherence to interventions of diet and exercise is rarely reported, with few standard methods existing to measure adherence.

Objective

We aimed to assess the maternal diet quality and create an algorithm to evaluate adherence to an intervention of high protein/dairy nutrition and walking exercise from early pregnancy to birth.

Methods

In Be Healthy in Pregnancy randomized trial (NCT01693510), diet quality was measured using scores from an adapted PrimeScreen food frequency questionnaire, nutrient intake assessed by 3-day diet records, and physical activity using accelerometry at 14-17 (early), 26-28 (middle), and 36-38 (late) weeks' gestation. A novel adherence score was derived by combining data for compliance with prescribed protein and energy intakes and daily step counts in the intervention group. Between-group diet quality scores and changes in adherence scores in the intervention group across pregnancy were analyzed using generalized estimating equations adjusted for prepregnancy body mass index and study site.

Results

Diet scores were similar for intervention (n = 55) and control (n = 56) groups at baseline but only the intervention group significantly improved and maintained their scores from early to middle (18.7 ± 7.6 vs. 22.9 ± 6.1; P < 0.001) and late (22.5 ± 6.9; P < 0.008) pregnancy. Protein intake was significantly (P < 0.001) higher but energy intakes were similar in the intervention group compared with those in the control group. Adherence scores for the intervention increased significantly (P < 0.01) from early (1.52 ± 0.70) to midpregnancy (1.89 ± 0.82) but declined from midpregnancy to late (1.55 ± 0.78; P < 0.0005) pregnancy primarily owing to lower step counts.

Conclusions

Adherence to an intervention may decline toward the end of pregnancy, particularly in maintaining physical activity. Creation of adherence scores is a feasible approach to measure combined intervention compliance for diet and physical activity and may increase transparency in interpreting results of randomized trials in pregnancy.This trial was registered at clinicaltrials.gov as NCT01689961 (https://clinicaltrials.gov/ct2/show/NCT01689961?cond=NCT01689961&rank=1; registered on 21 September 2012).

Meeting physical activity guidelines and its association with health-related quality of life throughout pregnancy: the PregnActive project

Pregnancy is a unique period in women life, characterized by anatomical and metabolic variation that may affect health-related quality of life (HRQoL). Physical activity has the potential to positively influence HRQoL. The aim of this study is to analyze the association between the fulfillment of physical activity guidelines and HRQoL throughout pregnancy. Seventy-eight pregnant women were assessed at two time point through their pregnancy: at mid- and at later-pregnancy. Physical activity was objectively assessed by a multi-sensor monitor and pregnant women were categorized by the fulfillment of the minimum physical activity recommendations: at least 30 minutes/day on at least 5 days/week. Perceived mental health was evaluated by health-related quality of life and by psychological pregnancy symptoms, using the SF-36 and the Pregnancy Symptoms Inventory, respectively. T-Student Test and hierarchical multiple linear regressions analysis was developed. Pregnant women who fulfilled physical activity recommendations reported better mental HRQoL both at mid-pregnancy (p = 0.148) and later-pregnancy (p = 0.007). The number of days meeting minimum physical activity recommendations contributes to better mental HRQoL and together with depression and anxiety symptoms the model explain the 65% of the mental HRQoL at later pregnancy. Meeting the minimum physical activity recommendations is associated with better perceived health at both midpregnancy and later pregnancy. While mental HRQoL is explained by physical activity, physical HRQoL is explained by others factors such as age or pregnancy-related symptoms, but not by meeting the minimum physical activity recommendations.

Effects of a behavioral intervention on physical activity, diet, and health-related quality of life in pregnant women with elevated weight: results of the HIPP randomized controlled trial

BACKGROUND

Physical activity (PA), diet, and health-related quality of life (HRQOL) are related to maternal and infant health, but interventions to improve these outcomes are needed in diverse pregnant women with elevated weight.

METHODS

Health In Pregnancy and Postpartum (HIPP) was a randomized controlled trial. Women who were pregnant (N=219, 44% African American, 56% white) with overweight or obesity but otherwise healthy were randomized to a behavioral intervention grounded in Social Cognitive Theory (n=112) or to standard care (n=107). The intervention group received an in-depth counseling session, a private Facebook group, and 10 content-based counseling calls with accompanying behavioral podcasts followed by weekly or biweekly counseling calls until delivery. The standard care group received monthly mailings and 10 podcasts focused on healthy pregnancy. PA (SenseWear armband), diet (ASA24), and HRQOL (SF-12) measures were obtained from blinded assessors at baseline (<16 weeks) and late pregnancy (32 weeks). Mixed model repeated measures regression models tested treatment (Group x Time) and within-group effects. We hypothesized that intervention participants would have higher levels of PA, a better-quality diet, and higher HRQOL than standard care participants. Exploratory analyses examined whether changes in outcomes over time differed according to whether participants had recommended, excessive, or inadequate weight gain.

RESULTS

Treatment effects favored intervention participants for vegetable intake (d=0.40, p<0.05) and % whole grains (d=0.60, p<0.01). HRQOL mental component improved in both groups, but less in intervention than standard care participants (d=-0.33, p<0.05). Time effects demonstrated that total PA, steps/day, and HRQOL physical component declined significantly in both groups. Within-group effects showed that diet quality significantly improved in intervention participants. Moderate-intensity PA declined significantly in standard care participants, whereas light-intensity PA declined and sedentary behavior increased significantly in intervention participants. Finally, exploratory analyses showed that total PA and light PA increased whereas sedentary behavior decreased among those meeting guidelines for weight gain, with opposite patterns seen among those with excessive or inadequate weight gain.

CONCLUSIONS

The intervention improved several dietary outcomes but had modest impacts on PA and HRQOL, underscoring the challenge of behavior change during pregnancy.

TRIAL REGISTRATION

This trial was registered in ClinicalTrials.gov on 10/09/2014. NCT02260518.

Metabolome-Wide Associations of Gestational Weight Gain in Pregnant Women with Overweight and Obesity

Excessive gestational weight gain (GWG) is associated with adverse pregnancy outcomes. This metabolome-wide association study aimed to identify metabolomic markers for GWG. This longitudinal study included 39 Black and White pregnant women with a prepregnancy body mass index (BMI) of ≥ 25 kg/m2. Untargeted metabolomic profiling was performed using fasting plasma samples collected at baseline (mean: 12.1 weeks) and 32 weeks of gestation. The associations of metabolites at each time point and changes between the two time points with GWG were examined by linear and least absolute shrinkage and selection operator (LASSO) regression analyses. Pearson correlations between the identified metabolites and cardiometabolic biomarkers were examined. Of the 769 annotated metabolites, 88 metabolites at 32 weeks were individually associated with GWG, with four (phosphatidylcholine (PC) 34:4, triacylglycerol (TAG) 52:6, arachidonic acid, isoleucine) jointly associated with GWG (area under the receiver operating characteristic curve (AUC) for excessive GWG: 0.80, 95% CI: 0.67, 0.93). No correlations were observed between the 88 metabolites and insulin, C-peptide, and high-sensitivity C-reactive protein at 32 weeks. Twelve metabolites at baseline (AUC for excessive GWG: 0.80, 95% CI: 0.62, 0.99) and three metabolite changes (AUC for excessive GWG: 0.73, 95% CI: 0.44, 1.00) were jointly associated with GWG. We identified novel metabolites in the first and third trimesters associated with GWG, which may shed light on the pathophysiology of GWG.

Sleep and physical activity from before conception to the end of pregnancy in healthy women: a longitudinal actigraphy study

BACKGROUND

Sleep and physical activity changes are common in pregnancy, but longitudinal data starting before conception are scarce. Our aim was to determine the changes of the daily total sleep time (TST) and physical activity duration (PAD) from before conception to end of pregnancies in respect of pregestational maternal factors.

METHODS

This longitudinal observational study formed part of the CONIMPREG research project and recruited healthy women planning to become pregnant. Sleep and physical activity were recorded around-the-clock for ≥4 days via actigraphy before conception and during each trimester of pregnancy. Data were adjusted according to pregestational maternal body composition, parity and age.

RESULTS

Among 123 women with eligible data, the unadjusted mean (95% confidence interval) TST increased from 415.3 min (405.5-425.2 min) before conception to 458.0 min (445.4-470.6 min) in the 1st trimester, remaining high through the 2nd and 3rd trimesters. Variation was substantial before conception (±2SD range: 307-523 min). The unadjusted mean PAD before conception was 363.7 min (±2SD range: 120-608 min), decreasing sharply to 262.1 min in the first trimester and more gradually thereafter. Vigorous and moderate activity decreased more than light activity. TST and PAD were significantly associated with age, parity, and pregestational body fat percentage; lean body mass was negatively correlated with TST. Results were generally unaffected by seasonal variations.

CONCLUSION

Marked variations were found in pregestational TST and PAD. Healthy women slept ≥30 min longer during pregnancy, while PAD decreased by ≥ 90 min in early pregnancy and continued to decrease thereafter.

A Behavioral Lifestyle Intervention to Limit Gestational Weight Gain in Pregnant Women with Overweight and Obesity

OBJECTIVE

This study aimed to evaluate the effects of an antenatal behavioral lifestyle intervention on total gestational weight gain (GWG) and perinatal outcomes.

METHODS

Pregnant women with overweight and obesity in South Carolina were recruited into a theory-based randomized controlled trial (n = 112 intervention, n = 105 standard care), which was designed to target weight self-monitoring, increased physical activity, and improved dietary practices.

RESULTS

Participants were racially/ethnically diverse (44% African American). Intervention and standard care participants had similar total GWG at delivery (12.9 ± 6.9 vs. 12.4 ± 8.3 kg, respectively), but intervention participants had a smaller standard deviation (P = 0.04) in total GWG. The treatment effects were moderated by race/ethnicity and prepregnancy BMI. Among African American participants with overweight, intervention participants gained 4.5 kg less, whereas, among African American women with obesity, intervention participants gained 4.1 kg more than standard care participants. Total GWG among White participants was similar regardless of weight status and group assignment. Fewer intervention participants than standard care participants had adverse pregnancy outcomes (P ≤ 0.01).

CONCLUSIONS

The behavioral lifestyle intervention favorably impacted GWG in African American participants with overweight but not African American participants with obesity. The intervention's overall favorable impact on perinatal outcomes suggests that the mechanisms beyond total GWG may drive these outcomes.

Body composition helps: Differences in energy expenditure between pregnant and nonpregnant females

OBJECTIVES

Human pregnancy is associated with important physiological changes that usually increase energetic requirements. However, great variability exists in the costs and mechanisms required to bear pregnancy. Since body mass (BM) and composition are modified during gestation, it is of great interest to compare the influence of BM on energy expenditure (EE) in pregnant and nonpregnant females.

METHODS

BM, body composition, and EE of 77 volunteers (35 pregnant and 42 nonpregnant females) were measured. The pregnant volunteers completed two measurement rounds at 28 and 32 gestation weeks. Differences on the measured parameters were sought, and comparison of regression lines was computed to test how BM affected the EE of the volunteers.

RESULTS

BM and body composition parameters are significantly higher in pregnant females, but EE is not statistically different. Pregnant females have a larger percentage of fat mass, but lower percentage of fat-free mass (FFM). The EE per kg of FFM is similar in both groups. Comparison of regression lines shows that pregnancy does not change the relationship between BM and EE, but for similar BM pregnant females expend less energy than nonpregnant females.

CONCLUSIONS

We propose that their larger percentage of passive body tissues is the reason why pregnant females expend less energy than nonpregnant females of similar BM, without changing the scaling of EE on BM. Thus, pregnancy could not be as energetically constraining as usually assumed, with important consequences for human reproductive ecology.

Associations of 24-hours activity composition with adiposity and cardiorespiratory fitness: The PregnActive project

AIM

This study examined the associations of activity behaviors composition (sleep, sedentary time, light and moderate-to-vigorous physical activity) with adiposity and cardiorespiratory fitness, and how isotemporal reallocations of time between activity behaviors are associated with differences in adiposity and cardiorespiratory fitness.

METHODS

A cross-sectional study was conducted in 130 women during midpregnancy. Activity behaviors, conceptualized as a 24-hours composition, were objectively assessed by multi-sensor monitors. Skinfold thickness, fat mass index, and body mass index were calculated as indicators of adiposity. Cardiorespiratory fitness was assessed using a 6-minute walk test. Log-ratio multiple linear regression models and compositional isotemporal substitutions were used to analyze the associations and estimated differences in outcomes.

RESULTS

The activity composition was significantly associated with adiposity indicators (all P < .001) and cardiorespiratory fitness (P values from .025 to <.001) during midpregnancy. The isotemporal substitutions were asymmetrical, showing the highest estimated differences in adiposity (8.7%, 0.80 kg/m² , for fat mass index; 6.0%, 2.65 mm, for the sum of skinfold thickness; and 3.8%, 1.02 kg/m² , for body mass index) and cardiorespiratory fitness (3.0%, 1.00 mL/kg min) when 30 minutes of moderate-to-vigorous physical activity was reallocated by sedentary time.

CONCLUSION

The activity composition was associated with adiposity and the cardiorespiratory fitness levels during midpregnancy, with moderate-to-vigorous physical activity being the leading activity behavior. The most unfavorable differences in adiposity and cardiorespiratory fitness were found when moderate-to-vigorous physical activity was replaced by another behavior, mainly sedentary time, reinforcing the importance of at least maintaining moderate-to-vigorous physical activity during pregnancy.

Walking for health during pregnancy: A literature review and considerations for future research

Walking is the most commonly chosen type of physical activity (PA) during pregnancy and provides several health benefits to both mother and child. National initiatives have promoted the importance of walking in general, but little emphasis is directed toward pregnant women, the majority of whom are insufficiently active. Pregnant women face a variety of dynamic barriers to a physically active lifestyle, some of which are more commonly experienced during specific times throughout the pregnancy experience. Walking is unique in that it appears resistant to a number of these barriers that limit other types of PA participation, and it can be meaningfully integrated into some transportation and occupational activities when leisure-time options are unavailable. Preliminary intervention work suggests that walking programs can be effectively adopted into a typical pregnancy lifestyle. However, a great deal of work remains to administer successful pregnancy walking interventions, including developing and using validated methods of PA and walking assessment. This narrative review discusses the unique advantages of walking during pregnancy, provides recommendations for future intervention work, and outlines the need for pregnancy-focused community walking initiatives. Standard search procedures were followed to determine sources from the literature specific to walking during pregnancy for use in each section of this review.

The Behavioral Wellness in Pregnancy study: a randomized controlled trial of a multi-component intervention to promote appropriate weight gain

BACKGROUND

Adequate weight gain during pregnancy is important to both maternal and fetal outcomes. To date, randomized controlled trials have not been effective at increasing the proportion of women meeting gestational weight-gain guidelines.

OBJECTIVES

The aim of this study was to determine whether a multi-component behavioral intervention with a Registered Dietitian Nutritionist significantly improves the proportion of women who adhere to the 2009 Institute of Medicine weight-gain guidelines.

METHODS

Participants were randomly assigned to usual care (UC; n = 24) or intervention (n = 23) between 8 and 14 weeks of gestation. The intervention included a minimum of 6 one-on-one counseling sessions over ∼30 wk focusing on healthy diet and physical activity (PA) goals. In addition to the face-to-face visits, weekly communication via email supported healthy eating, PA, and appropriate weight gain. Gestational weight gain, PA, and diet were assessed at 8-14, 26-28, and 34-36 weeks of gestation; weight retention was measured 2 mo postpartum.

RESULTS

The proportion of women meeting the guidelines was significantly greater in those receiving the intervention than UC (60.8% compared with 25.0%, OR: 4.7; 95% CI: 1.3, 16.2; P = 0.019). Furthermore, 36.4% of the intervention women were at or below their prepregnancy weight at 2 mo postpartum compared with 12.5% in the UC group (P = 0.05).

CONCLUSIONS

A multi-component behavioral intervention improved adherence to the 2009 Institute of Medicine weight-gain guidelines. This trial was registered with clinicaltrials.gov as NCT02168647.

Measuring Sedentary Behavior During Pregnancy: Comparison Between Self-reported and Objective Measures

Objectives To quantify and compare the sedentary time estimated by the Sedentary Behavior Questionnaire (SBQ) and the sedentary time objectively measured by a multi-sensor monitor (SWA) in pregnant women. Methods One hundred eighty-six participants answered the SBQ and wore the SWA at least 7 valid days. The concordance, correlation, agreement and relative activity levels between both measures of sedentary time were examined. Differences of sedentary time between weekday and weekend and between groups stratified by sociodemographic and clinical characteristic were evaluated by one-way analysis of variance. Results Pregnant women were sedentary the 64% of their waking hours. Television viewing is the most prevalent sedentary behavior. The concordance, correlation, and agreement between SBQ and SWA were weak, yet a significant correlation in weekday and average day sedentary time (r = 0.23 and 0.20, P = 0.001 and 0.008, respectively) was observed. A significant linear trend was found for increasing sedentary time between both methods using a relative activity levels analysis. Conclusions for Practice Pregnant women experience high amount of sedentary time, for approximately half of the day. The SBQ shows a low validity and agreement, but strong ability to rank individuals compared with SWA in pregnant women.

Physical Activity Device Reliability and Validity during Pregnancy and Postpartum

Current physical activity (PA) recommendations for women experiencing a normal pregnancy reflect recent research showing numerous health benefits for mother and offspring. However, few studies have evaluated PA devices' reliability and validity during pregnancy, because anatomical and physiological changes throughout gestation could affect an instrument's accuracy.

PURPOSE

This study aimed to determine the reliability and validity of PA devices worn on the hip, ankle, and triceps during pregnancy and postpartum.

METHODS

Thirty-three women performed six activities of daily living and one treadmill walk at approximately 21 and 32 wk of pregnancy, and 12 wk postpartum. There were two visits at each time period, 1 wk apart. Energy expenditure (oxygen consumption) was measured by using indirect calorimetry (IC; criterion measure), whereas PA was quantified by using accelerometers and pedometers placed at the right hip and ankle and left triceps. Interclass reliability and monitor validity compared with IC in relative (mL·kg·min) terms were calculated using Pearson correlation. Both multitrial and single-trial intraclass reliabilities (ICC) were estimated using ANOVA to assess monitor reliability at each time period. SEM values were calculated in relative terms for each time period.

RESULTS

The reliability of the devices was moderate/strong because 66% of the Pearson correlations were between 0.6 and 1.0. Multitrial ICC values were largely in the moderate/strong range because 38% of the ICC values were between 0.6 and 0.79 and 50% were between 0.8 and 1.0. The SEM values for each device between visits ranged from 7% to 23% of the mean values. Comparison between IC and devices showed that 40% and 46% of the validity coefficients were between 0.4 and 0.59 and between 0.6 and 0.79, respectively.

CONCLUSIONS

PA devices show moderate/strong reliability and moderate validity for measuring PA during pregnancy and postpartum.

Explanatory factors and levels of health-related quality of life among healthy pregnant women at midpregnancy: A cross-sectional study of The PregnActive Project

AIMS

To identify potential explanatory factors and establish health-related quality of life (HRQoL) levels of healthy pregnant women at midpregnancy.

BACKGROUND

The HRQoL levels perceived by pregnant women are lower than those perceived by women of similar age and decline during the course of pregnancy.

DESIGN

An exploratory cross-sectional design was used.

METHODS

One hundred thirty-four healthy women from antenatal clinics completed questionnaires were administered a cardiorespiratory fitness (CRF) test and wore a multisensor body monitor for 7 days at midpregnancy. Data were collected from September 2015-December 2016.

RESULTS

Cardiorespiratory fitness, musculoskeletal symptoms, and age were identified as explanatory factors of the physical component summary of HRQoL. Explanatory factors of the mental component summary included musculoskeletal and psychological symptoms and light activity. Significant differences in HRQoL levels were identified among groups of pregnant women stratified by age, occupational status, pregnancy symptoms, and CRF.

CONCLUSIONS

Modifiable factors of HRQoL, such as CRF and active lifestyle may be important areas to target in interventions aimed at promoting HRQoL in healthy women at midpregnancy. The identification of the groups of pregnant women with lower levels of HRQoL may help midwives and health professional to focus their advice and conduct interventions on these groups of pregnant women. These modifiable factors should be considered in future longitudinal studies to determine causal effects, will likely help improve multidisciplinary treatments.

Transcultural adaptation and psychometric properties of Spanish version of Pregnancy Physical Activity Questionnaire: the PregnActive project

OBJECTIVE

To transculturally adapt the Spanish version of Pregnancy Physical Activity Questionnaire (PPAQ) analyzing its psychometric properties.

METHODS

The PPAQ was transculturally adapted into Spanish. Test-retest reliability was evaluated in a subsample of 109 pregnant women. The validity was evaluated in a sample of 208 pregnant women who answered the questionnaire and wore the multi-sensor monitor for 7 valid days. The reliability (intraclass correlation coefficient), concordance (concordance correlation coefficient), correlation (Pearson correlation coefficient), agreement (Bland-Altman plots) and relative activity levels (Jonckheere-Terpstra test) between both administrations and methods were examined.

RESULTS

Intraclass correlation coefficients between both administrations were good for all categories except transportation. A low but significant correlation was found for total activity (light and above) whereas no correlation was found for other intensities between both methods. Relative activity levels analysis showed a significant linear trend for increased total activity between both methods.

CONCLUSIONS

Spanish version of PPAQ is a brief and easily interpretable questionnaire with good reliability and ability to rank individuals, and poor validity compared with multi-sensor monitor. The use of PPAQ provides information of pregnancy-specific activities in order to establish physical activity levels of pregnant women and adapt health promotion interventions.

A randomized controlled trial to prevent excessive gestational weight gain and promote postpartum weight loss in overweight and obese women: Health In Pregnancy and Postpartum (HIPP)

BACKGROUND

Interventions to prevent excessive gestational weight gain and promote postpartum weight loss have yielded modest results, particularly in overweight and obese women.

OBJECTIVES

To examine the impact of a theory-based lifestyle intervention on gestational weight gain, postpartum weight loss, and related maternal and child outcomes and to examine race differences in these outcomes.

DESIGN

A randomized controlled trial (target N=400; 200 intervention, 200 standard care; 200 African American, 200 white).

METHODS

Overweight and obese African American and white women ≤16weeks gestation are recruited from obstetrics and gynecology clinics in South Carolina. Intervention participants receive two in-depth counseling sessions (early pregnancy and postpartum), telephone counseling, behavioral podcasts, and social media support that target weight self-monitoring and increasing physical activity and healthy dietary behavior practices, guided by Social Cognitive Theory. Standard care participants receive monthly mailings and a matched number of podcasts on non-weight related topics. All intervention activities last from ≤18weeks gestation to 6months after delivery. Gestational weight gain is the primary outcome. Secondary outcomes are meeting gestational weight gain guidelines (inadequate, adequate, excessive), weekly rate of gestational weight gain, postpartum weight retention, physical activity and dietary behaviors, health-related quality of life, and offspring adiposity. Participants are assessed at baseline (≤16weeks gestation), 32weeks gestation, and 6 and 12months postpartum, and offspring are assessed at 6 and 12months.

SUMMARY

HIPP is an innovative study that addresses significant gaps in the literature. Primary outcome results are expected in 2019.

Reliability and concurrent validity of the International Physical Activity Questionnaire short form among pregnant women

ABSTRACT

Sanda B, Vistad I, Haakstad LAH, Berntsen S, Sagedal LR, Lohne-Seiler H, Torstveit MK. Reliability and concurrent validity of the International Physical Activity Questionnaire short form among pregnant women.

BACKGROUND

The International Physical Activity Questionnaire short-form (IPAQ-SF) is frequently used to assess physical activity (PA) level in the general adult population including pregnant women. However, the reliability and validity of the questionnaire in pregnancy is unknown. Therefore, the aims of the present study were to investigate test-retest reliability and concurrent validity of IPAQ-SF among pregnant women, and whether PA is reported differently among those who fulfill (active) vs. do not fulfill (inactive) recommendations of ≥150 min of weekly moderate intensity PA in pregnancy.

METHOD

Test-retest reliability was examined by answering IPAQ-SF twice, two weeks apart (n = 88). To assess validity, IPAQ-SF was compared to the physical activity monitor SenseWear Armband® (SWA) (n = 64). The participants wore SWA for 8 consecutive days before answering IPAQ-SF. PA level was reported as time spent in moderate-, vigorous- and moderate-to-vigorous intensity PA (MPA, VPA and MVPA) corresponding to the cut-off points 3-6, >6 and >3 Metabolic Equivalents (METs), respectively.

RESULTS

Test-retest intraclass-correlation of MPA, VPA and MVPA ranged from 0.81-0.84 (95% Confidence Intervals: 0.69,0.90). Comparing time spent performing PA at various intensities; the mean differences and limits of agreement (±1.96 Standard Deviation) from Bland-Altman plots were-84 ± 402 min/week for MPA,-85 ± 452 min/week for MVPA and 26 ± 78 min/week for VPA, illustrating that the total group under-reported MPA by 72% and MVPA by 52%, while VPA was over-reported by 1400%. For the inactive group corresponding numbers were 44 ± 327 min/week for MPA, 52 ± 355 min/week for MVPA and 16 ± 33 min/week for VPA, illustrating that the inactive group over-reported MPA by 13% and MVPA by 49%, while VPA was not detected by SWA, but participants reported 16 min of VPA/week. In contrast, corresponding numbers for the active group were-197 ± 326 min/week for MPA,-205 ± 396 min/week for MVPA and 35 ± 85 min/week for VPA, illustrating that the active group under-reported MPA by 81% and MVPA by 60%, while they over-reported VPA by 975%.

CONCLUSION

IPAQ-SF had good test-retest reliability, but low to fair concurrent validity for MPA, VPA and MVPA compared to an objective criterion measure among pregnant women. Further, women fulfilling PA guidelines in pregnancy under-reported, while inactive women over-reported PA level.

Validity of SenseWear® Armband v5.2 and v2.2 for estimating energy expenditure

We compared SenseWear Armband versions (v) 2.2 and 5.2 for estimating energy expenditure in healthy adults. Thirty-four adults (26 women), 30.1 ± 8.7 years old, performed two trials that included light-, moderate- and vigorous-intensity activities: (1) structured routine: seven activities performed for 8-min each, with 4-min of rest between activities; (2) semi-structured routine: 12 activities performed for 5-min each, with no rest between activities. Energy expenditure was measured by indirect calorimetry and predicted using SenseWear v2.2 and v5.2. Compared to indirect calorimetry (297.8 ± 54.2 kcal), the total energy expenditure was overestimated (P < 0.05) by both SenseWear v2.2 (355.6 ± 64.3 kcal) and v5.2 (342.6 ± 63.8 kcal) during the structured routine. During the semi-structured routine, the total energy expenditure for SenseWear v5.2 (275.2 ± 63.0 kcal) was not different than indirect calorimetry (262.8 ± 52.9 kcal), and both were lower (P < 0.05) than v2.2 (312.2 ± 74.5 kcal). The average mean absolute per cent error was lower for the SenseWear v5.2 than for v2.2 (P < 0.001). SenseWear v5.2 improved energy expenditure estimation for some activities (sweeping, loading/unloading boxes, walking), but produced larger errors for others (cycling, rowing). Although both algorithms overestimated energy expenditure as well as time spent in moderate-intensity physical activity (P < 0.05), v5.2 offered better estimates than v2.2.

Predicting who fails to meet the physical activity guideline in pregnancy: a prospective study of objectively recorded physical activity in a population-based multi-ethnic cohort

BACKGROUND

A low physical activity (PA) level in pregnancy is associated with several adverse health outcomes. Early identification of pregnant women at risk of physical inactivity could inform strategies to promote PA, but no studies so far have presented attempts to develop prognostic models for low PA in pregnancy. Based on moderate-to-vigorous intensity PA (MVPA) objectively recorded in mid/late pregnancy, our objectives were to describe MVPA levels and compliance with the PA guideline (≥150 MVPA minutes/week), and to develop a prognostic model for non-compliance with the PA guideline.

METHODS

From a multi-ethnic population-based cohort, we analysed data from 555 women with MVPA recorded in gestational week (GW) 28 with the monitor SenseWear™ Pro3 Armband. Predictor variables were collected in early pregnancy (GW 15). We organized the predictors within the domains health, culture, socioeconomic position, pregnancy, lifestyle, psychosocial factors, perceived preventive effect of PA and physical neighbourhood. The development of the prognostic model followed several steps, including univariate and multiple logistic regression analyses.

RESULTS

Overall, 25 % complied with the PA guideline, but the proportion was lower in South Asians (14 %) and Middle Easterners (16 %) compared with Westerners (35 %). Among South Asians and Middle Easterners, 35 and 28 %, respectively, did not accumulate any MVPA minutes/week compared with 18 % among Westerners. The predictors retained in the prognostic model for PA guideline non-compliance were ethnic minority background, multiparity, high body fat percentage, and perception of few physically active friends. The prognostic model provided fair discrimination between women who did vs. did not comply with the PA guideline.

CONCLUSION

Overall, the proportion who complied with the PA guideline in GW 28 was low, and women with ethnic minority background, multiparity, high body fat percentage and few physically active friends had increased probability of non-compliance. The prognostic model showed fair performance in discriminating between women who did comply and those who did not comply with the PA guideline.

SenseWearMini and Actigraph GT3X Accelerometer Classification of Observed Sedentary and Light-Intensity Physical Activities in a Laboratory Setting

Purpose: To compare the ability of SenseWear Mini (SWm) and Actigraph GT3X (AG₃) accelerometers to differentiate between healthy adults' observed sedentary and light activities in a laboratory setting. Methods: The 22 participants (15 women, 7 men), ages 19 to 72 years, wore SWm and AG₃ monitors and performed five sedentary and four light activities for 5 minutes each while observed in a laboratory setting. Performance was examined through comparisons of accuracy, sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios. Correct identification of both types of activities was examined using area under the receiver operating characteristic curve (AUC). Results: Both monitors demonstrated excellent ability to identify sedentary activities (sensitivity>0.89). The SWm monitor was better at identifying light activities (specificity 0.61-0.71) than the AG₃ monitor (specificity 0.27-0.47) and thus also showed a greater ability to correctly identify both sedentary and light activities (SWm AUC 0.84; AG₃ AUC 0.62-0.73). Conclusions: SWm may be a more suitable monitor for detecting time spent in sedentary and light-intensity activities. This finding has clinical and research relevance for evaluation of time spent in lower intensity physical activities by sedentary adults.

Examining the energy cost and intensity level of prenatal yoga

CONTEXT

A popular form of pregnancy physical activity (PA) is prenatal yoga. However, little is known about the intensity and energy cost of this practice.

AIMS

To examine the energy cost and intensity level of prenatal yoga.

METHODS

Pregnant women in a prenatal yoga class (n = 19) wore a Sense Wear Armband during eleven 60 min classes each, and self-reported demographic variables, height and weight, prepregnancy weight, and PA behaviors and beliefs. Sense Wear Armband data included kilocalories, metabolic equivalent (MET) values, and time spent in various intensities. Descriptive statistics and frequencies were utilized to describe energy expenditure and intensity.

RESULTS

Energy expenditure averaged 109 ± 8 kcals, and the average MET value was 1.5 ± 0.02. On average, 93% and 7% of classes were sedentary and moderate intensity PA, respectively.

CONCLUSIONS

Time spent in a prenatal yoga class was considered to be primarily a sedentary activity. Future research should utilize larger samples, practice type, and skill level to increase generalizability.

Preventing excessive weight gain during pregnancy and promoting postpartum weight loss: a pilot lifestyle intervention for overweight and obese African American women

To test the feasibility and acceptability of a theory-based lifestyle intervention designed to prevent excessive weight gain during pregnancy and promote weight loss in the early postpartum period in overweight and obese African American women. Sixteen pregnant women (≤18 weeks gestation) were recruited from prenatal clinics in Columbia, South Carolina in 2011 and assigned to a lifestyle intervention program. The intervention, guided by formative research, consisted of an individual counseling session followed by eight group sessions alternated with telephone counseling contacts that continued through 36 weeks of gestation. At 6-8 weeks postpartum, participants received a home visit and up to three counseling calls through week 12. Medical charts were reviewed for 38 contemporary controls who met the same inclusion criteria and attended the same prenatal clinics. Compared to controls, study participants gained less total weight, had a smaller weekly rate of weight gain across the 2nd and 3rd trimesters (0.89 vs. 0.96 lbs), and were less likely to exceed weight gain recommendations (56.3 vs. 65.8 %). At 12 weeks postpartum, study participants retained 2.6 lbs from their prepregnancy weight, half of study participants were at their prepregnancy weight or lower, and only 35 % retained ≥5 lbs. The intervention also demonstrated success in promoting physical activity and reducing caloric intake, and was well-received by participants. The initial results were promising. The lessons learned can help inform future studies. The efficacy of our intervention will be tested in a large randomized controlled trial.

Alterations in energy homeostasis to favour adipose tissue gain: A longitudinal study in healthy pregnant women

BACKGROUND

Pregnancy is associated with an increase in body fat; however, excessive gestational weight gain predisposes to significant maternal and neonatal morbidity and mortality. It remains unclear whether alterations in energy homeostasis have a major influence on fat storage.

AIMS

To evaluate longitudinal changes in body composition and energy metabolism in healthy pregnant women.

MATERIALS AND METHODS

Body composition, energy expenditure and energy intake were measured longitudinally in 26 women with singleton pregnancies at 12-14 weeks, 24-26 weeks and 34-36 weeks of gestation. Fat mass (FM) and lean body mass (LBM) were measured using bio-impedance analysis, total energy expenditure (TEE) using the Sensewear Armband and energy intake through a 3-day food recall diary.

RESULTS

Throughout pregnancy, all women remained healthy. Body weight increased by 10.8 ± 3.9 kg, from 67.3 ± 14.1 kg to 78.1 ± 13.8 kg from the first to the third trimester (P < 0.001). Body fat percentage increased by 4.5 ± 4.2% (P < 0.001). LBM also increased throughout pregnancy, by 3.9 ± 2.4 kg (P < 0.001). TEE increased significantly from the first to the third trimesters (9514 kJ/day to 10 263 kJ/day; P < 0.05). In contrast, energy expenditure due to physical activity, energy intake and macronutrient intake did not change significantly throughout pregnancy.

CONCLUSION

Healthy women increase FM during pregnancy despite slight increases in TEE and no change in energy intake. This suggests that energy storage efficiency improves during pregnancy, which may be related to alterations in gut microbiota and activation of anabolic pathways during pregnancy. Clarifying factors leading to this more efficient fat and energy storing state, and the role of the pregnancy-related changes in gut microbiota, may be important for managing gestational weight gain.

Validity and reliability of Nike + Fuelband for estimating physical activity energy expenditure

Background

The Nike + Fuelband is a commercially available, wrist-worn accelerometer used to track physical activity energy expenditure (PAEE) during exercise. However, validation studies assessing the accuracy of this device for estimating PAEE are lacking. Therefore, this study examined the validity and reliability of the Nike + Fuelband for estimating PAEE during physical activity in young adults. Secondarily, we compared PAEE estimation of the Nike + Fuelband with the previously validated SenseWear Armband (SWA).

Methods

Twenty-four participants (n = 24) completed two, 60-min semi-structured routines consisting of sedentary/light-intensity, moderate-intensity, and vigorous-intensity physical activity. Participants wore a Nike + Fuelband and SWA, while oxygen uptake was measured continuously with an Oxycon Mobile (OM) metabolic measurement system (criterion).

Results

The Nike + Fuelband (ICC = 0.77) and SWA (ICC = 0.61) both demonstrated moderate to good validity. PAEE estimates provided by the Nike + Fuelband (246 ± 67 kcal) and SWA (238 ± 57 kcal) were not statistically different than OM (243 ± 67 kcal). Both devices also displayed similar mean absolute percent errors for PAEE estimates (Nike + Fuelband = 16 ± 13 %; SWA = 18 ± 18 %). Test-retest reliability for PAEE indicated good stability for Nike + Fuelband (ICC = 0.96) and SWA (ICC = 0.90).

Conclusion

The Nike + Fuelband provided valid and reliable estimates of PAEE, that are similar to the previously validated SWA, during a routine that included approximately equal amounts of sedentary/light-, moderate- and vigorous-intensity physical activity.

Validation of the SenseWear Armband in different ambient temperatures

This study examines the validity of the SenseWear Armband in different temperatures using the old (SenseWear v2.2) and newest version of the algorithm (SenseWear v5.2) against indirect calorimetry (IC). Thirty-nine male and female students (21.1 ± 1.41 years) completed an exercise trial in 19°C, 26°C and 33°C consisting of 5 min standing followed by alternating walking/running at 35% and 65% of their maximal oxygen uptake. The accuracy of the algorithms was evaluated by comparing estimated energy expenditure (EE) to IC using a mixed-model design. No difference was reported in EE between the different temperatures for IC. Both algorithms estimated EE significantly higher when exercising at high intensity in 33°C compared to 19°C. Compared to IC, SenseWear v2.2 accurately estimated EE during standing and light intensity exercise but underestimated EE when exercising in a hot environment and at high intensity. SenseWear v5.2 showed a difference when exercising at high intensity in thermoneutral and warm conditions. The new algorithm improved EE estimation in hot environments and at high intensity compared to the old version. However, given the inherent inaccuracy of the EE estimates of SenseWear, greater weight should be given to direct monitor outputs rather than the ability of a monitor to estimate EE precisely.

Validity of physical activity measures in individuals after total knee arthroplasty

OBJECTIVE

To determine the concurrent criterion-related validity of 2 activity monitors in comparison with the criterion method of indirect calorimetry in older adults after total knee arthroplasty (TKA).

DESIGN

Validation study.

SETTING

Subjects completed 9 increasingly demanding daily activities in a research laboratory; each activity was performed for 7 minutes, for a total of 80 minutes, while the activity monitors and criterion method were used concurrently.

PARTICIPANTS

Subjects (N=21, 67% women) had a mean age ± SD of 68±7 years and a body mass index of 29±4.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Energy expenditure (in kcal/min) measured by accelerometer-based and multisensor-based monitors and by a criterion method. Validity was assessed by the paired t test, intraclass correlation coefficient (ICC), and Bland-Altman plots comparing the measurements from the activity monitors with those of the criterion method.

RESULTS

Measurements from the accelerometer-based monitor were significantly lower than those of the criterion method across all walking and nonwalking activities. The underestimations ranged from 40% to 100%. The accelerometer-based monitor demonstrated small to moderate agreement compared with the criterion method (ICCs from 0 to .38). Measurements from the multisensor-based monitor were significantly lower than those of the criterion method during several nonwalking activities; yet, the differences were minor (2%-19%). Measurements from the multisensor-based monitor during walking activities were not different compared with the criterion method. The multisensor-based monitor demonstrated moderate to excellent agreement with the criterion method (ICCs from .48 to .81).

CONCLUSIONS

The multisensor-based monitor showed better criterion-related validity than the accelerometer-based monitor and should be considered as a tool to measure physical activity in individuals after TKA.

Energy Expenditure in Institutionalized Older Adults: Validation of SenseWear Mini

PURPOSE

Objective methods to quantify physical activity (PA) and predict energy expenditure (EE) are needed in the old and old-old. The aim of the present study was to evaluate the validity of EE estimates by the SenseWear Mini (SWMini) compared with indirect calorimetry during daily life activities in institutionalized older adults.

METHODS

Sixty nursing home residents (mean age = 85.5 ± 5.5 yr) wore the SWMini during rest (sitting quietly) and three activity tasks (walking, sitting/rising/walking, and moving objects). SWMini data were processed using software version 7.0. The criterion EE (kcal·min⁻¹) was estimated by a portable gas analyzer, Oxycon Mobile (OM).

RESULTS

The analyses revealed high correlations (rsitting = 0.68, ractivity tasks = 0.88) between EE estimated by OM and SWMini. EE increased between sitting periods and activity tasks for EE estimated by OM (mean difference = 61.5% ± 8.9%), as well as for EE estimated by SWMini (mean difference = 58.2% ± 7.4%) (P < 0.001). However, SWMini significantly underestimated EE, with an overall absolute percent error of 14.1% ± 7.9%. The largest absolute percent differences were observed during sitting periods compared with activity tasks (P < 0.05). Older age significantly reduced accuracy, explaining 12% of the variance in total percent error (β = 0.42, t = 2.84, P < 0.05).

CONCLUSIONS

The high percent error scores indicate that the SWMini is of limited value for quantifying EE in the old and old-old. The accuracy could be improved by developing accurate age- and activity-specific algorithms. On the other hand, the SWMini can be used as a suitable device for researchers interested in specific levels and patterns of PA and sedentary behavior.

Techniques to measure free-living energy expenditure during pregnancy - A guide for clinicians and researchers

As maternal overweight and obesity increase in prevalence, the need to optimise gestational weight gain has entered the forefront due to the well-documented poor fetal and maternal outcomes associated with excess adipose tissue. Measurements of changes in energy expenditure form crucial components of effective weight management programmes, and they are also important for clarifying the energy requirements of pregnancy. This review evaluates the primary techniques for measuring free-living energy expenditure for use in pregnancy, with special consideration of the dynamic physiological changes that occur in this state. The methods that will be discussed include the doubly labelled water method, activity recall and activity logs, heart rate monitors and motion sensors. This article may be useful for clinicians seeking to implement active gestational weight management by enabling advice on increases in caloric intake linked to measured changes in energy expenditure, and for researchers studying energy metabolism in pregnancy.

Monitoring human health behaviour in one's living environment: a technological review

The electronic monitoring of human health behaviour using computer techniques has been an active research area for the past few decades. A wide array of different approaches have been investigated using various technologies including inertial sensors, Global Positioning System, smart homes, Radio Frequency IDentification and others. It is only in recent years that research has turned towards a sensor fusion approach using several different technologies in single systems or devices. These systems allow for an increased volume of data to be collected and for activity data to be better used as measures of behaviour. This change may be due to decreasing hardware costs, smaller sensors, increased power efficiency or increases in portability. This paper is intended to act as a reference for the design of multi-sensor behaviour monitoring systems. The range of technologies that have been used in isolation for behaviour monitoring both in research and commercial devices are reviewed and discussed. Filtering, range, sensitivity, usability and other considerations of different technologies are discussed. A brief overview of commercially available activity monitors and their technology is also included.

Physical activity during pregnancy: impact of applying different physical activity guidelines

Multiple guidelines and definitions of physical activity (PA) have been used to study the benefits of activity during pregnancy. The different guidelines lead to a wide range of prevalence estimates and this has led to conflicting reports about activity patterns during pregnancy. A longitudinal study was conducted to assess PA using a pattern-recognition monitor for a 7-day period at week 18 (n = 55) and week 35 (n = 66) of pregnancy. The amount of activity performed and the number of women meeting six different PA guidelines were evaluated. Adherence to PA guidelines ranged from 5 to 100% and 9 to 100% at weeks 18 and 35, respectively. All women achieved the 500 MET-minute guideline and nearly all women accumulated ≥150 minutes of weekly moderate-vigorous physical activity (MVPA) at both time points. Only 22% and 26% participated in ≥3 sessions of MVPA lasting ≥30 minutes at both time points and this further declined to 5% and 9% when the guideline was increased to ≥5 sessions of 30 minutes. The amount of PA during pregnancy varied drastically depending on which guideline was used. Further research is warranted to clearly identify the patterns of activity that are associated with healthy pregnancy outcomes.