Measuring Physical Activity During Pregnancy

Physical activity and pregnancy outcomes: an expert review

This expert review aimed to assess current literature on the effect and tracking of physical activity during pregnancy and associated outcomes. Self-reported physical activity may be inaccurate given the subjective nature of the questionnaires. The accelerometer ActiGraph is considered the "gold standard" to objectively measure physical activity. However, other more user-friendly wearable devices are now widely available and may accurately track physical activity. Conclusive data from both validated activity questionnaires and accelerometers indicate that physical activity is safe during pregnancy. In addition, studies of physical activity during pregnancy that evaluate pregnancy outcomes have found reduced risks of preterm birth, preeclampsia, and gestational diabetes mellitus and improved mental health among individuals who regularly engage in physical activity. In the United States, approximately 48% of pregnant individuals gain more than the recommended amount of weight during pregnancy; excessive gestational weight gain is associated with an increased risk of maternal and fetal complications, including preterm birth, preeclampsia, and gestational diabetes mellitus, and corresponding higher adverse short- and long-term maternal and offspring health outcomes. Although physical activity is safe during pregnancy and may reduce excessive gestational weight gain and resultant pregnancy complications, further research is needed to determine the frequency and duration of specific types of physical activity during pregnancy. Providers should encourage physical activity before and during pregnancy and educate patients regarding the benefits and safety of physical activity.

The association of physical activity on homocysteine in pregnant women

INTRODUCTION

Women with high levels of physical activity have improved pregnancy, labor, and delivery outcomes related to cardiovascular health. Hyperhomocysteinemia, which predicts cardiovascular disease risk, is associated with maternal vascular complications during pregnancy, such as placental abruption and preeclampsia. However, studies are lacking on whether physical activity impacts homocysteine in pregnant women, pointing to a potential mechanism behind the improved cardiovascular health in women who exercise during pregnancy. The purpose of this study was to examine if women with high levels of physical activity have lower levels of homocysteine compared to women with low levels of physical activity.

METHODS

This study was a secondary analysis using data from the 2003 to 2006 National Health and Nutrition Examination Survey. A total of 257 pregnant women were included. Physical activity was assessed objectively over seven days with accelerometers. High and low groups based on moderate-to-vigorous physical activity (MVPA) and steps/day were defined. Homocysteine and related laboratory biomarkers (vitamin B12, folate, pyridoxal 5'-phosphate) were assessed through blood draws. Data assembly was performed using SAS and analysis via SPSS Complex Samples.

RESULTS

Only an estimated 17.7 ± 4.7% of women met guidelines to achieve at least 150 min per week of MVPA. Plasma homocysteine was not different between pregnant women with high and low levels of moderate-to-vigorous physical activity (4.39 ± 0.21 and 4.44 ± 0.17 µmol/L; p > .05) or between those with high and low levels of steps (3.95 ± 0.26 and 4.62 ± 0.27 µmol/L; p > .05) when the data was split into two quantiles by the median. These results were similar when using log-transformed values for homocysteine to normalize the distribution of data. Pregnant women in the group of the high steps tended to have higher vitamin B12, folate, and pyridoxal 5'-phosphate than those in the group of the low steps. Sensitivity analyses revealed that homocysteine was not different between the upper 25% (4.04 ± 0.22 µmol/L) and lower 25% (4.17 ± 0.26 µmol/L) MVPA (p = .716) but that it was statistically higher in the low (<5000 steps/day) (4.99 ± 0.20 µmol/L) steps/day group compared to high (>7500 steps/day) steps/day (3.99 ± 0.23 µmol/L) (p = .003) after excluding individuals with hypertension and thyroid/kidney issues.

CONCLUSION

Maternal steps/day, but not MVPA, appear to be associated with homocysteine (albeit weakly) in the present study after excluding potential factors which impact homocysteine. The volume of physical activity appears to be an important indicator as this difference was not revealed until the physical activity was more distinctly separated.

The association between level of physical activity and pregnancy rate after embryo transfer: a prospective study

RESEARCH QUESTION

Is physical activity after embryo transfer, as assessed by a smart band activity tracker, associated with decreased pregnancy rates?

DESIGN

Prospective observational cohort study comprising infertile women aged < 38 years, who had undergone fewer than three previous embryo transfers, achieved a good ovarian response and were undergoing frozen-thawed embryo transfer in a tertiary-referral centre. A validated smart band activity tracker was used to assess physical activity level immediately after the embryo transfer and until the pregnancy test. No specific recommendations were given to participants on level or intensity of physical activity. Physicians and patients were blinded to the data stored in the pedometer. Primary outcome was ongoing pregnancy rate.

RESULTS

Fifty women met the inclusion criteria. Ongoing pregnancy rate was 30%. In a pooled analysis, participants walked significantly fewer steps per day on the day of embryo transfer compared with the first 2 days after embryo transfer (4075, interquatile range [IQR] 2932-5592 versus 5204, IQR4203-8584, P = 0.01). No significant difference was observed between pregnant women and non-pregnant women in the median steps per day after embryo transfer until serum beta-HCG was measured (7569, IQR 6008-10884 versus 6572.5, IQR 5299-8786, P = 0.43). No significant difference was observed in the median number of steps on the day of embryo transfer or the first 2 days after embryo transfer between pregnant and non-pregnant women.

CONCLUSIONS

A quantitative objective assessment of the association between physical activity and pregnancy rates after frozen-thawed embryo transfer was conducted. Ambulation after embryo transfer has no adverse effect on pregnancy rates and, therefore, women should resume regular activity immediately after embryo transfer.

A feasibility study of activity tracking devices in pregnancy

BACKGROUND

We aimed to evaluate the feasibility of using an activity-tracking device (ATD) during pregnancy and compare self-reported to ATD-calculated energy expenditure in a 2-phase study.

METHODS

(Phase 1) Twenty-five pregnant women were asked about exercise, computer use, smartphone ownership, and ATD attitudes. Descriptive statistics were reported. (Phase 2) Women ≥18 years, smartphone owners, < 16-weeks gestation, and without exercise restrictions were approached to participate in 2016-2017. Women received instructions to wear and sync the ATD daily. We assessed protocol adherence and satisfaction via surveys at 36-weeks and used mixed models to assess the relationship between gestational age and ATD data. Energy expenditure from the Pregnancy Physical Activity Questionnaire (PPAQ) was compared to ATD-calculated energy expenditure.

RESULTS

(Phase 1) Walking was the most common exercise; 8% did not perform any activity during pregnancy. All women had internet access and owned a smartphone. Women stated they would wear the ATD all the time during a pregnancy (88%), with the intent to improve their health (80%). (Phase 2) The characteristics of the 48 women were: pre-pregnancy BMI 28, 62% non-Hispanic black, 62% multiparas. Of the 18 women who completed the 36-week survey, only 56% wore the ATD daily, 33% had a lost or broken ATD, and 17% had technical problems; however, 94% enjoyed wearing it, 94% would recommend it to a pregnant friend, and 78% thought it helped them reach activity goals. According to ATD data, the median number of active days was 41 (IQR 20-73) and the median proportion of active days out of potential days was 22% (IQR 11-40). As gestational age increased, mean log steps decreased, active minutes decreased, and sedentary hours increased in unadjusted and adjusted models (P < 0.05 all comparisons). There were no differences in mean energy expenditure (MET-h/week) estimated by PPAQ or ATD data at 28 weeks gestation [212 (22-992 range) vs. 234 (200-281 range), P = 0.66] and at 36 weeks [233 (86-907 range) vs. 218 (151-273 range), P = 0.68]).

CONCLUSIONS

Women reported high motivation to wear an ATD and high satisfaction with actually using an ATD during pregnancy; however adherence to the study protocol was lower than expected and ATD technical problems were frequent.

The Reliability and Validity of the Turkish Kaiser Physical Activity Survey for Pregnant Women

BACKGROUND

Evaluation of physical activity by condition-specific surveys provides more accurate results than generic physical activity questionnaires. The aim of this study was to investigate the reliability and validity of the Kaiser Physical Activity Survey (KPAS) in Turkish pregnant women.

METHODS

In the translation and cultural adaptation of the KPAS, the 6-phase guidelines recommended in the literature were followed. The study included a total of 151 pregnant women who were assessed using the Turkish version of KPAS, the Pregnancy Physical Activity Questionnaire, and the SenseWear Pro3 Armband. To determine the test-retest reliability, the KPAS was reapplied after 7 days. The psychometric properties of KPAS were analyzed with respect to internal consistency, test-retest reliability, and concurrent validity.

RESULTS

Cronbach α coefficient indicating the internal consistency of the Turkish KPAS was found to be .60 to .80, showing moderate reliability. The intraclass correlation coefficient for test-retest reliability was very strong (intraclass correlation coefficient: .96-.98). The total KPAS scores were found to be moderately correlated with the total Pregnancy Physical Activity Questionnaire score and the total energy expenditure value on the SenseWear Pro3 Armband.

CONCLUSIONS

This study showed that KPAS is a valid and reliable instrument for evaluating physical activity in Turkish pregnant women in different aspects.

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.

Pregnancy Induces an Earlier Chronotype in Both Mice and Women

Daily rhythms generated by endogenous circadian mechanisms and synchronized to the light-dark cycle have been implicated in the timing of birth in a wide variety of species. Although chronodisruption (e.g., shift work or clock gene mutations) is associated with poor reproductive outcomes, little is known about circadian timing during pregnancy. This study tested whether daily rhythms change during full-term pregnancies in mice and women. We compared running wheel activity continuously in both nonpregnant ( n = 14) and pregnant ( n = 13) 12- to 24-week-old C57BL/6NJ mice. We also monitored wrist actigraphy in women ( N = 39) for 2 weeks before conception and then throughout pregnancy and measured daily times of sleep onset. We found that on the third day of pregnancy, mice shift their activity to an earlier time compared with nonpregnant dams. Their time of daily activity onset was maximally advanced by almost 4 h around day 7 of pregnancy and then shifted back to the nonpregnant state approximately 1 week before delivery. Mice also showed reduced levels of locomotor activity during their last week of pregnancy. Similarly, in women, the timing of sleep onset was earlier during the first and second trimesters (gestational weeks 4-13 and 14-27) than before pregnancy and returned to the prepregnant state during the third trimester (weeks 28 until delivery). Women also showed reduced levels of locomotor activity throughout pregnancy. These results indicate that pregnancy induces changes in daily rhythms, altering both time of onset and amount of activity. These changes are conserved between mice and women.

Physical Activity Questionnaires for Pregnancy: A Systematic Review of Measurement Properties

Background

In order to assess physical activity (PA) during pregnancy, it is important to choose the instrument with the best measurement properties.

Objectives

To systematically summarize, appraise, and compare the measurement properties of all self-administered questionnaires assessing PA in pregnancy.

Methods

We searched PubMed, Embase, and SPORTDiscus with the following inclusion criteria: (i) the study reported at least one measurement property (reliability, criterion validity, construct validity, responsiveness) of a self-administered questionnaire; (ii) the questionnaire intended to measure PA; (iii) the questionnaire was evaluated in healthy pregnant women; and (iv) the study was published in English. We evaluated results, quality of individual studies, and quality of evidence using a standardized checklist (Quality Assessment of Physical Activity Questionnaires [QAPAQ]) and the GRADE (Grading of Recommendation, Assessment, Development, and Evaluation) approach.

Results

Seventeen articles, reporting 18 studies of 11 different PA questionnaires (17 versions), were included. Most questionnaire versions showed insufficient measurement properties. Only the French and Turkish versions of the Pregnancy Physical Activity Questionnaire (PPAQ) showed both sufficient reliability and construct validity. However, all versions of the PPAQ pooled together showed insufficient construct validity. The quality of individual studies was usually high for reliability but varied considerably for construct validity. Overall, the quality of evidence was very low to moderate.

Conclusions

We recommend the PPAQ to assess PA in pregnancy, although the pooled results revealed insufficient construct validity. The lack of appropriate standards in data collection and processing criteria for objective devices in measuring PA during pregnancy attenuates the quality of evidence. Therefore, research on the validity of comparison instruments in pregnancy followed by consensus on validation reference criteria and standards of PA measurement is needed.

Electronic supplementary material

The online version of this article (10.1007/s40279-018-0961-x) contains supplementary material, which is available to authorized users.

Activity Tracking Devices in Group Prenatal Care: A Feasibility Study

To evaluate the feasibility (adherence to the study protocol and satisfaction) of using an activity tracking device (ATD) in group prenatal care. Women participated if they (1) were in group prenatal care, (2) owned a smartphone, and (3) had no activity restrictions. Women were instructed to wear and sync the ATD daily. Protocol adherence and satisfaction were assessed via surveys. Mixed models assessed the relationship between gestational age and ATD data. Self-reported energy expenditure from the Pregnancy Physical Activity Questionnaire (PPAQ) was compared with ATD-calculated energy expenditure. The baseline characteristics of the 49 women were as follows: 24 years old, prepregnancy body mass index 28, 80% Hispanic, 86% nulliparas, and 21 weeks of gestation. Of the 30 women who completed the follow-up survey, 47% self-reported wearing the ATD daily, 27% reported a lost or broken ATD, and 22% reported technical problems; however, 97% enjoyed wearing it, 100% would recommend it to a pregnant friend, and 77% thought it helped them reach activity goals. According to ATD data, the median active days were 47 (interquartile range [IQR] 21-79) and the median proportion of active days of potential days was 43.7% (IQR 15.4-77.1). For women who wore the ATD for the first 7 days, mean steps/day were 7574 (range 3076-15,828), active minutes/day were 277 (range 145-475), and sedentary hours/day were 12 (range 7.8-16.2). As gestational age increased, mean log steps decreased, mean active minutes decreased, and mean sedentary hours increased in unadjusted and adjusted models (p < 0.001 all comparisons). There were no differences in mean energy expenditure (MET-h/week) by PPAQ or ATD data at 28 weeks of gestation [231 (62-927 range) vs. 238 (212-290 range), p = 0.74] and at 36 weeks of gestation [145 (35-581 range) vs. 222 (196-272 range), p = 0.27]. Most women reported high satisfaction with an ATD in group prenatal care, yet adherence to the study protocol was low and ATD technical problems were common. As gestational age increased, activity decreased while sedentary time increased, suggesting that additional research is needed to find ways to engage women in physical activity during pregnancy.

Quantitative assessment of physical activity in pregnant women with sonographic short cervix and the risk for preterm delivery: A prospective pilot study

Objective

Bed rest or activity restriction is a common obstetrical practice, despite a paucity of data to support its efficacy. The aim of this study was to determine whether physical activity, as assessed by a smart band activity tracker, is associated with preterm birth in pregnant women at high risk for preterm delivery.

Methods

This was a pilot prospective cohort study including pregnant women at high risk for preterm delivery between 24 and 32 weeks-of-gestation. Physical activity level was assessed by smart band activity. Patients with sonographic short cervical length (≤ 20 mm) were asked to wear the smart band activity tracker continuously for at least one week, including one weekend. Both physicians and patients were blinded to the data stored in the smart band activity tracker. No specific recommendations were given to participants as to the level or intensity of physical activity. The primary outcome was the rate of preterm birth (< 37 weeks-of-gestation). Secondary outcomes included the rate of delivery before 34 weeks of gestation and neonatal outcome. Parametric and nonparametric statistics were used for analysis.

Results

Study population included 49 pregnant women: 37 women (75.7%) delivered preterm and 12 (24.5%) delivered at or after 37 weeks-of-gestation. The median steps per day was significantly lower in patients who delivered preterm (3576, IQR: 2478–4775 vs. 4554, IQR: 3632–6337, p = 0.02). Regression analysis revealed that the median number of steps per day was independently inversely associated with preterm birth, after adjustment for maternal age, body mass index, gestational age at recruitment, cervical length, cervical dilatation and plurality.

Conclusion

This pilot study represents the first quantitative assessment of the association between physical activity and preterm birth. The results of this pilot study do not support the efficacy of decreased physical activity in the prevention of preterm birth in patients with sonographic short cervical length.

Acceptability and validity of a home exercise diary used in home-based pulmonary rehabilitation: A secondary analysis of a randomised controlled trial

INTRODUCTION

Evaluating adherence to home-based pulmonary rehabilitation (PR) could be challenging due to lack of direct supervision and the complex nature of the rehabilitation model. To measure adherence to home-based PR in the HomeBase trial, participants were encouraged to work towards a goal of at least 30 min of whole-body exercise on most days of the week and report their participation using a home exercise diary.

OBJECTIVE

This project aimed to evaluate the acceptability and validity of the home exercise diary.

METHODS

Diary return and completion rates assessed acceptability of the home exercise diary. Home participants underwent physical activity (PA) monitoring using the Sensewear armband during the final week of an 8-week PR. The correlation between self-documented and objective daily exercise minutes was calculated. Objective exercise minutes were defined as bouts of ≥10 min spent in ≥ moderate PA. Differences in self-documented weekly exercise minutes between sufficiently active (≥7000 daily steps) and inactive participants were computed.

RESULTS

Diaries were returned by 92% of programme completers. Of those who returned diaries, 72% have completed exercise documentation. Fifteen programme completers underwent PA monitoring [mean age 69 (9) (SD) years, FEV₁ 55 (19) %predicted]. A moderate correlation was observed between self-documented and objective mean daily exercise minutes (r = .59, P = .02). Active participants [n = 6, 10 253 (1521) daily steps] documented more exercise (111 min) during week eight compared with inactive participants [n = 9, 2705 (1772) daily steps, P = .002].

CONCLUSION

The self-documented home exercise diary is an acceptable and valid method to reflect exercise participation during home-based PR.

What Adherence Measures Should Be Used in Trials of Home-Based Rehabilitation Interventions? A Systematic Review of the Validity, Reliability, and Acceptability of Measures

OBJECTIVE

To systematically review methods for measuring adherence used in home-based rehabilitation trials and to evaluate their validity, reliability, and acceptability.

DATA SOURCES

In phase 1 we searched the CENTRAL database, NHS Economic Evaluation Database, and Health Technology Assessment Database (January 2000 to April 2013) to identify adherence measures used in randomized controlled trials of allied health professional home-based rehabilitation interventions. In phase 2 we searched the databases of MEDLINE, Embase, CINAHL, Allied and Complementary Medicine Database, PsycINFO, CENTRAL, ProQuest Nursing and Allied Health, and Web of Science (inception to April 2015) for measurement property assessments for each measure.

STUDY SELECTION

Studies assessing the validity, reliability, or acceptability of adherence measures.

DATA EXTRACTION

Two reviewers independently extracted data on participant and measure characteristics, measurement properties evaluated, evaluation methods, and outcome statistics and assessed study quality using the COnsensus-based Standards for the selection of health Measurement INstruments checklist.

DATA SYNTHESIS

In phase 1 we included 8 adherence measures (56 trials). In phase 2, from the 222 measurement property assessments identified in 109 studies, 22 high-quality measurement property assessments were narratively synthesized. Low-quality studies were used as supporting data. StepWatch Activity Monitor validly and acceptably measured short-term step count adherence. The Problematic Experiences of Therapy Scale validly and reliably assessed adherence to vestibular rehabilitation exercises. Adherence diaries had moderately high validity and acceptability across limited populations. The Borg 6 to 20 scale, Bassett and Prapavessis scale, and Yamax CW series had insufficient validity. Low-quality evidence supported use of the Joint Protection Behaviour Assessment. Polar A1 series heart monitors were considered acceptable by 1 study.

CONCLUSIONS

Current rehabilitation adherence measures are limited. Some possess promising validity and acceptability for certain parameters of adherence, situations, and populations and should be used in these situations. Rigorous evaluation of adherence measures in a broader range of populations is needed.

Optimising the validity and completion of adherence diaries: a multiple case study and randomised crossover trial

BACKGROUND

Diaries are the most commonly used adherence measurement method in home-based rehabilitation trials, yet their completion and validity varies widely between trials. We aimed to: (1) generate theory to explain this variation, (2) create an optimised diary and (3) evaluate the optimised diary's validity.

METHODS

Stage 1.

DEVELOPMENT

using a multiple case study approach, we collected trialist interviews (n = 7), trial publications (n = 16) and diaries (n = 7) from seven purposively sampled UK rehabilitation trials. We explored return rates, diary designs and trialists' ideas as to what affected diary completion and validity. Using explanatory case study analysis, we developed a diary optimisation model. Stage 2.

EVALUATION

we compared a diary optimised according to several model components to one nonoptimised according to the same components in a randomised AB/BA crossover trial. Healthy adults aged 60+ years without mobility impairments undertook a home-based 8-week walking programme. They recorded walking duration and frequency for 4 weeks per diary. We hypothesised that the optimised diary would possess greater validity for self-reported adherence to walking duration (criterion: the Activpal accelerometer), assessed during each diary's final week. Participants were blinded to the hypothesis. Secondary outcomes included test-retest reliability and acceptability. Ethical approval was granted from Glasgow Caledonian University.

RESULTS

Thirty-two out of 33 participants completed the study. Diaries did not significantly differ in validity, reliability or acceptability. Both diaries agreed closely with the Activpal when assessing duration adherence at a group level, however, inter and intraindividual variation in validity was high (mean difference (95 % limits of agreement (LOA): limits of agreement plot the difference between measurements collected using two different methods against their mean and thus assess the extent to which the two measures agree with each other)) optimised diary = 3.09 % (-103.3 to 109.5 %), nonoptimised diary = -0.34 % (-131.1 to 130.5 %), p = 0.732). We found similarly wide LOA for percentage of days adhered to and percentage of walks taken, whilst frequency adherence was underestimated. Participants rated both diaries as low-burden and equal numbers favoured each diary or were neutral. Preference appeared to impact minimally upon validity.

CONCLUSION

Group-level adherence diary data are likely to be valid. However, individual diary data lack validity, which raises concerns if using this data in calculations such as predicting functional outcomes. Different diary designs are likely interchangeable, though unanticipated high variation meant that this study was underpowered.

TRIAL REGISTRATION

The trial was not eligible for registration in a clinical trial database as diary measurement property outcomes, not clinical health outcomes of participants, were assessed.

The Turkish version of the pregnancy physical activity questionnaire: cross-cultural adaptation, reliability, and validity

[Purpose] The aim of this study was to translate the Pregnancy Physical Activity Questionnaire, adapt it for use with Turkish subjects and determine its reliability and validity. [Subjects and Methods] The Pregnancy Physical Activity Questionnaire was translated into Turkish and administered twice at 7–14-day intervals to pregnant women to assess the test-retest reliability. Cronbach’s α was used for internal consistency, and the inter-rater correlation coefficient was used to calculate the test-retest reliability. The Turkish Short Form 36 Health Survey (SF-36) and the International Physical Activity Questionnaire were used to estimate validity. [Results] The internal consistency during the first and third trimesters of pregnancy was excellent, with Cronbach’s α values of 0.93 and 0.95, respectively. The mean interval between the two assessments was 11.1 ± 2.1 days. The correlation coefficient between the total activity measured by the Turkish version of the Pregnancy Physical Activity Questionnaire and the International Physical Activity Questionnaire estimates of the total metabolic equivalent were fair to poor during the first, second, and third trimesters of pregnancy (r = 0.17, r = 0.17, r = 0.21, respectively). The Turkish version of the Pregnancy Physical Activity Questionnaire showed fair correlations with the Short Form 36 Health Survey physical component score (r = −0.30) and mental component score (r = −0.37) for the first trimester of pregnancy. [Conclusion] The Turkish version of the Pregnancy Physical Activity Questionnaire was found to be reliable and valid for assessing a pregnant woman’s physical activity.

Travel patterns during pregnancy: comparison between Global Positioning System (GPS) tracking and questionnaire data

BACKGROUND

Maternal exposures to traffic-related air pollution have been associated with adverse pregnancy outcomes. Exposures to traffic-related air pollutants are strongly influenced by time spent near traffic. However, little is known about women's travel activities during pregnancy and whether questionnaire-based data can provide reliable information on travel patterns during pregnancy.

OBJECTIVES

Examine women's in-vehicle travel behavior during pregnancy and examine the difference in travel data collected by questionnaire and global positioning system (GPS) and their potential for exposure error.

METHODS

We measured work-related travel patterns in 56 pregnant women using a questionnaire and one-week GPS tracking three times during pregnancy (<20 weeks, 20-30 weeks, and >30 weeks of gestation). We compared self-reported activities with GPS-derived trip distance and duration, and examined potentially influential factors that may contribute to differences. We also described in-vehicle travel behavior by pregnancy periods and influences of demographic and personal factors on daily travel times. Finally, we estimated personal exposure to particle-bound polycyclic aromatic hydrocarbon (PB-PAH) and examined the magnitude of exposure misclassification using self-reported vs. GPS travel data.

RESULTS

Subjects overestimated both trip duration and trip distance compared to the GPS data. We observed moderately high correlations between self-reported and GPS-recorded travel distance (home to work trips: r = 0.88; work to home trips: r = 0.80). Better agreement was observed between the GPS and the self-reported travel time for home to work trips (r = 0.77) than work to home trips (r = 0.64). The subjects on average spent 69 and 93 minutes traveling in vehicles daily based on the GPS and self-reported data, respectively. Longer daily travel time was observed among participants in early pregnancy, and during certain pregnancy periods in women with higher education attainment, higher income, and no children. When comparing self-reported vs. GPS data, we found that estimated personal exposure to PB-PAH did not differ remarkably at the population level, but the difference was large at an individual level.

CONCLUSION

Self-reported home-to-work data overestimated both trip duration and trip distance compared to GPS data. Significant differences in PAH exposure estimates were observed at individual level using self-reported vs. GPS data, which has important implications in air pollution epidemiological studies.

Preventing long-term risk of obesity for two generations: prenatal physical activity is part of the puzzle

Background. The period surrounding pregnancy has been identified as a risk period for overweight/obesity in both mother and child because of excessive gestational weight gain (GWG). The promotion of a healthy GWG is therefore of paramount importance in the context of the prevention of obesity in the current and next generations. Objective. To provide a comprehensive overview of the effect of prenatal physical activity interventions, alone or in combination with nutritional counselling, on GWG and to address whether preventing excessive GWG decreases the incidence of infant high birth weight and/or postpartum weight retention. Method. A search of the PubMed database was conducted to identify all relevant studies. Nineteen studies were included in this review: 13 interventions combining physical activity, nutrition, and GWG counselling and 6 interventions including physical activity alone. Results. Prenatal lifestyle interventions promoting healthy eating and physical activity habits appear to be the most effective approach to prevent excessive GWG. Achievement of appropriate GWG may also decrease the incidence of high infant birth weight and postpartum weight retention. Conclusion. Healthy eating habits during pregnancy, combined with an active lifestyle, may be important elements in the prevention of long-term risk of obesity for two generations.

Physical activity and pregnancy: past and present evidence and future recommendations

PURPOSE

In this review, we provide researchers and practitioners with an overview of the physical activity and pregnancy literature to promote prenatal physical activity, improve measurement, further elucidate the role of activity in reducing maternal health complications, and inform future research.

METHOD

We examined past and present physical activity and pregnancy studies and highlight key papers with a focus on maternal health outcomes to best inform physical activity promotion efforts.

RESULTS

We discuss: (a) historical overview of prenatal physical activity relative to the physical activity guidelines, how they have changed over time, and how evidence of the effect of prenatal activity on maternal/fetal health outcomes has affected clinical recommendations; (b) existing tools and challenges associated with measuring prenatal physical activity; (c) empirical evidence on multilevel determinants of prenatal activity to guide future intervention work; (d) empirical evidence of prenatal activity on adverse maternal outcomes (gestational diabetes mellitus, preeclampsia, excessive gestational weight gain) from observational and intervention studies; and (e) summary/recommendations for future research and practice.

CONCLUSIONS

The physical activity and pregnancy literature has evolved over the past 50 years, and there is sufficient empirical evidence to support the promotion of moderate-to-vigorous prenatal physical activity for maternal health benefits. Future studies and interventions should be carefully designed, theoretically driven, and include validated and reliable activity measures. Researchers and practitioners should also consider the multifaceted determinants and outcomes of prenatal physical activity and intervene to promote physical activity before, during, and after pregnancy.

Is intensive counseling in maternity care feasible and effective in promoting physical activity among women at risk for gestational diabetes? Secondary analysis of a cluster randomized NELLI study in Finland

BACKGROUND

Women who are physically active during early pregnancy have notably lower odds of developing gestational diabetes than do inactive women. The purpose of the intervention was to examine whether intensified physical activity (PA) counseling in Finnish maternity care is feasible and effective in promoting leisure-time PA (LTPA) among pregnant women at risk of gestational diabetes.

METHODS

Fourteen municipalities were randomized to intervention (INT) and usual care group (UC). Nurses in INT integrated five PA counseling sessions into routine maternity visits and offered monthly group meetings on PA instructed by physiotherapists. In UC conventional practices were continued. Feasibility evaluation included safety (incidence of PA-related adverse events; questionnaire), realization (timing and duration of sessions, number of sessions missed, attendance at group meetings; systematic record-keeping of the nurses and physiotherapists) and applicability (nurses' views; telephone interview). Effectiveness outcomes were weekly frequency and duration of total and intensity-specific LTPA and meeting PA recommendation for health self-reported at 8-12 (baseline), 26-28 and 36-37 weeks' gestation. Multilevel analysis with adjustments was used in testing for between-group differences in PA changes.

RESULTS

The decrease in the weekly days of total and moderate-to-vigorous-intensity LTPA was smaller in INT (N = 219) than in UC (N = 180) from baseline to the first follow-up (0.1 vs. -1.2, p = 0.040 and -0.2 vs. -1.3, p = 0.016). A similar trend was seen in meeting the PA recommendation (-11%-points vs. -28%-points, p = 0.06). INT did not experience more adverse events classified as warning signs to terminate exercise than UC, counseling was implemented as planned and viewed positively by the nurses.

CONCLUSIONS

Intensified counseling had no effects on the duration of total or intensity-specific weekly LTPA. However, it was able to reduce the decrease in the weekly frequency of total and moderate-to-vigorous-intensity LTPA from baseline to the end of second trimester and was feasibly embedded into routine practices. TR

Review of self-reported physical activity assessments for pregnancy: summary of the evidence for validity and reliability

BACKGROUND

Epidemiological studies and surveillance systems of pregnant women often rely on collection of physical activity through self-report. This systematic review identified and summarised self-reported physical activity assessments with evidence for validity and reliability among pregnant women.

METHODS

Peer-reviewed articles published through 2011 were included if they assessed validity and/or reliability of an interviewer- or self-administered physical activity questionnaire or diary among pregnant women.

RESULTS

We identified 15 studies, including 12 studies that assessed questionnaires and 4 studies that assessed diaries, conducted in Australia, Finland, Norway, the U.K., the U.S. and Vietnam. For questionnaires, 92% (11/12) assessed mode, all assessed frequency and/or duration and 58% (7/12) collected information on perceived intensity. All but one study (92%) assessed validity of the questionnaires. Questionnaires compared with objective measures (accelerometers, pedometers) ranged from slight to fair agreement, while comparison with other self-reported measures ranged from substantial to almost perfect agreement. Five studies (42%) assessed test-retest reliability of the questionnaires, ranging from substantial to almost perfect agreement. The four studies on diaries were all assessed for validity against objective measures, ranging from slight to substantial agreement.

CONCLUSIONS

Selection of valid and reliable physical activity measures that collect information on dose (type, frequency, duration, intensity) is recommended to increase precision and accuracy in detecting associations of physical activity with maternal and fetal outcomes.

Prenatal exercise research

In this review of recent research on prenatal exercise, studies from several different countries suggest that only approximately 40% of pregnant women exercise, even though about 92% are encouraged by their physicians to exercise, albeit with some 69% of the women being advised to limit their exercise. A moderate exercise regime reputedly increases infant birthweight to within the normal range, but only if exercise is decreased in late pregnancy. Lower intensity exercise such as water aerobics has decreased low back pain more than land-based physical exercise. Heart rate and blood pressure have been lower following yoga than walking, and complications like pregnancy-induced hypertension with associated intrauterine growth retardation and prematurity have been less frequent following yoga. No studies could be found on tai chi with pregnant women even though balance and the risk of falling are great concerns during pregnancy, and tai chi is one of the most effective forms of exercise for balance. Potential underlying mechanisms for exercise effects are that stimulating pressure receptors during exercise increases vagal activity which, in turn, decreases cortisol, increases serotonin and decreases substance P, leading to decreased pain. Decreased cortisol is particularly important inasmuch as cortisol negatively affects immune function and is a significant predictor of prematurity. Larger, more controlled trials are needed before recommendations can be made about the type and amount of pregnancy exercise.

Understanding health behaviours in a cohort of pregnant women at risk of gestational diabetes mellitus: an observational study

OBJECTIVE

To assess health behaviours, physical activity levels, weight gain and development of gestational diabetes mellitus (GDM) in high-risk women.

DESIGN

An observational sub-study of a larger randomised controlled trial.

SETTING

A large tertiary hospital in Australia.

POPULATION

Ninety-seven women (mean age 31.7 ± 4.5 years; body mass index 30.3 ± 5.9 kg/m(2) ) at risk of developing GDM.

METHODS

Women were identified as at risk of GDM based on a validated screening tool. Baseline measures were completed at 12-15 weeks of gestation and repeated at 26-28 weeks of gestation.

MAIN OUTCOME MEASURES

Anthropometric (weight and height) and physical activity assessment (Yamax pedometer and International physical activity questionnaire), questionnaires (self-efficacy) and GDM screening.

RESULTS

By 28 weeks of gestation, there was a high GDM prevalence of 26% using the recent International Association of Diabetes and Pregnancy Study Group criteria. Weight gain in overweight (body mass index 25-29.9 kg/m(2)) and obese (body mass index >30.0 kg/m(2)) women exceeded minimum total weight gain recommendations set by the Institute of Medicine (P < 0.01). Physical activity levels were low and declined during pregnancy (5437 ± 2951 steps/day to 4096 ± 2438 steps/day, respectively, P < 0.001). Despite reduced activity levels, increased weight gain and high GDM incidence many women did not accurately perceive GDM risk and were confident in their ability to control weight. A significant association with physical activity, weight and GDM outcome was not observed.

CONCLUSIONS

Overweight and obese pregnant women at risk for developing GDM demonstrate excessive weight gain and a reduced level of physical activity observed from early pregnancy to 28 weeks of gestation. Results highlight the need for targeted intervention in women at risk for developing GDM.

Accuracy of physical activity monitors in pregnant women

PURPOSE

To determine the step count accuracy of three pedometers and one accelerometer in pregnant women during treadmill walking.

METHODS

Participants were 30 women in the second or third trimester (20-34 wk) who were screened for pregnancy-related risk factors. Each participant was fitted with a belt containing three physical activity monitors: Yamax Digiwalker SW-200 (DW), New Lifestyles NL 2000 (NL), and GT3X ActiGraph accelerometer (ACT). The Omron HJ-720ITC (HJ) was placed in the pants' front pocket. Participants walked at 54, 67, 80, and 94 m · min for 2 min each. Actual steps were determined by an investigator using a hand-tally counter. The mean percent of steps recorded was calculated for each device at each speed and compared. Pearson correlations were used to determine the effect of body mass index and tilt angle on pedometer accuracy.

RESULTS

There was a significant interaction between speed and device (F9,20 = 7.574, P < 0.001). Across all speeds, the NL and HJ had the lowest error. The ACT and DW underestimated the actual steps taken, particularly at the slower walking speeds. At 54 m · min, the ACT averaged 77.5% of steps and the DW averaged 56.9% of steps. Significant differences in the mean percent of steps recorded were found between devices at all speeds. Body mass index was only significantly correlated with percent of steps recorded by the NL, and there were no significant correlations between steps recorded and tilt angle.

CONCLUSIONS

In pregnant women, the ACT and DW had more error than the NL and HJ. On the basis of these results, the NL and HJ should be considered for use in further research studies and physical activity programs that focus on walking during pregnancy.

Optimization of gestational weight gain in the obese gravida: a review

Because of the consistent association between gestational weight gain and birth weight (along with other maternal and child outcomes such as postpartum weight retention and child obesity), helping women avoid excessive weight gain during pregnancy should be an important objective of prenatal and preconceptional care. This article focuses on the updated Institute of Medicine gestational weight gain recommendations and measures directed at maintaining those guidelines and improving pregnancy outcome.

Measuring physical activity during pregnancy

BACKGROUND

Currently, little is known about physical activity patterns in pregnancy with prior estimates predominantly based on subjective assessment measures that are prone to error. Given the increasing obesity rates and the importance of physical activity in pregnancy, we evaluated the relationship and agreement between subjective and objective physical activity assessment tools to inform researchers and clinicians on optimal assessment of physical activity in pregnancy.

METHODS

48 pregnant women between 26-28 weeks gestation were recruited. The Yamax pedometer and Actigraph accelerometer were worn for 5-7 days under free living conditions and thereafter the International Physical Activity Questionnaire (IPAQ) was completed. IPAQ and pedometer estimates of activity were compared to the more robust and accurate accelerometer data.

RESULTS

Of 48 women recruited, 30 women completed the study (mean age: 33.6 ± 4.7 years; mean BMI: 31.2 ± 5.1 kg/m(2)) and 18 were excluded (failure to wear [n = 8] and incomplete data [n = 10]). The accelerometer and pedometer correlated significantly on estimation of daily steps (ρ = 0.69, p < 0.01) and had good absolute agreement with low systematic error (mean difference: 505 ± 1498 steps/day). Accelerometer and IPAQ estimates of total, light and moderate Metabolic Equivalent minutes/day (MET min(-1) day(-1)) were not significantly correlated and there was poor absolute agreement. Relative to the accelerometer, the IPAQ under predicted daily total METs (105.76 ± 259.13 min(-1) day(-1)) and light METs (255.55 ± 128.41 min(-1) day(-1)) and over predicted moderate METs (-112.25 ± 166.41 min(-1) day(-1)).

CONCLUSION

Compared with the accelerometer, the pedometer appears to provide a reliable estimate of physical activity in pregnancy, whereas the subjective IPAQ measure performed less accurately in this setting. Future research measuring activity in pregnancy should optimally encompass objective measures of physical activity.

TRIAL REGISTRATION

Australian New Zealand Clinical Trial Registry Number: ACTRN12608000233325. Registered 7/5/2008.

Padrão de atividade física entre gestantes atendidas pela estratégia saúde da família de Campina Grande - PB

INTRODUÇÃO: A atividade física realizada durante a gestação vem sendo discutida devido aos seus efeitos benéficos tanto para a saúde materna como para o crescimento fetal e desfechos gestacionais, porém ainda são escassos estudos sobre o padrão de atividade física neste período. OBJETIVO: Avaliar o padrão de atividade física entre gestantes atendidas pela estratégia Saúde da Família (ESF) do município de Campina Grande/PB. MÉTODOS:Foi acompanhada uma coorte observacional de gestantes (n=118), a partir da 16ª semana gestacional, durante os anos de 2005 a 2006. A cada quatro semanas eram aferidas as condições clínicas, socioeconômicas e obstétricas, incluindo a aplicação de um questionário específico sobre atividade física na 16ª, 24ª e 32ª semanas gestacionais. A avaliação foi feita a partir da somatória do equivalente metabólico (METs) e as atividades cotidianas foram divididas em quatro grupos: atividades laboral, doméstica e caminhada, além de inatividade. As gestantes foram classificadas de acordo com o padrão de atividade física realizado em: sedentárias, praticantes de atividades física leve, moderada e vigorosa. Os dados foram analisados no programa Epi Info 3.4.1. RESULTADOS: As características socioeconômicas da coorte estudada indicaram majoritariamente gestantes de baixo poder aquisitivo, baixa escolaridade e baixo percentual de mulheres economicamente ativas. O padrão de atividade física observado foi baixo desde o primeiro trimestre gestacional, oscilando entre o leve e o sedentário, e foi diminuindo com o evoluir da gravidez, com 100% das gestantes alcançando o padrão sedentário na 32ª semana. Em relação aos grupos de atividades, observou-se um predomínio de atividades domésticas, seguidas pelas atividades de lazer. CONCLUSÃO:Na coorte estudada verificou-se um padrão de atividade física inadequado desde o início da gestação, agravando-se no terceiro trimestre gestacional.

Physical activity and persistent low back pain and pelvic pain post partum

Background

The aims of this study were (i) to investigate the potential influence of pre-pregnancy regular leisure-time physical activity (PA) on the risk of persistent LBPP half a year after pregnancy, and (ii) to explore the starting time and prevalence of PA among women experiencing LBPP during pregnancy, in relation to remission or persistent LBPP half a year after pregnancy.

Methods

This study is a follow-up study of 639 women who reported LBPP during pregnancy. These women were sent a questionnaire at approximately six months after delivery. The respondents were divided into three groups: 'no pain', 'recurrent pain', and 'continuous pain'. Data were analysed using an independent samples t-test, Pearson's chi-squared test, and univariate and multivariate logistic regression analyses.

Results

44.5% of subjects reported current PA at six months post partum. The mean starting time of PA was 2.6 months post partum and the mean number of current, weekly events of PA was 3.4; there were no differences between the groups. 82.2% reported previous PA at some period in life. Women with BMI ≥ 30 reported current PA to a lesser extent. The number of years of pre-pregnancy PA did not influence the risk of persistent LBPP.

Conclusion

Almost half of women who had experienced LBPP during pregnancy reported PA at six months post partum. The number of years of pre-pregnancy PA did not influence the risk of persistent LBPP. Obesity was a risk factor for not practising PA.

A comparison of direct versus self-report measures for assessing physical activity in adults: a systematic review

BACKGROUND

Accurate assessment is required to assess current and changing physical activity levels, and to evaluate the effectiveness of interventions designed to increase activity levels. This study systematically reviewed the literature to determine the extent of agreement between subjectively (self-report e.g. questionnaire, diary) and objectively (directly measured; e.g. accelerometry, doubly labeled water) assessed physical activity in adults.

METHODS

Eight electronic databases were searched to identify observational and experimental studies of adult populations. Searching identified 4,463 potential articles. Initial screening found that 293 examined the relationship between self-reported and directly measured physical activity and met the eligibility criteria. Data abstraction was completed for 187 articles, which described comparable data and/or comparisons, while 76 articles lacked comparable data or comparisons, and a further 30 did not meet the review's eligibility requirements. A risk of bias assessment was conducted for all articles from which data was abstracted.

RESULTS

Correlations between self-report and direct measures were generally low-to-moderate and ranged from -0.71 to 0.96. No clear pattern emerged for the mean differences between self-report and direct measures of physical activity. Trends differed by measure of physical activity employed, level of physical activity measured, and the gender of participants. Results of the risk of bias assessment indicated that 38% of the studies had lower quality scores.

CONCLUSION

The findings suggest that the measurement method may have a significant impact on the observed levels of physical activity. Self-report measures of physical activity were both higher and lower than directly measured levels of physical activity, which poses a problem for both reliance on self-report measures and for attempts to correct for self-report - direct measure differences. This review reveals the need for valid, accurate and reliable measures of physical activity in evaluating current and changing physical activity levels, physical activity interventions, and the relationships between physical activity and health outcomes.

Activity levels among lower-limb amputees: self-report versus step activity monitor

OBJECTIVE

To determine the accuracy of self-reported activity by community-dwelling, lower-limb amputees.

DESIGN

Descriptive study.

SETTING

A regional prosthetics outpatient service.

PARTICIPANTS

Seventy-seven unilateral lower-limb amputees at least 6 months after prosthetic rehabilitation.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Measured activity counts (in steps/min) and self-reported activity (rest, low, medium, high) in 15-minute intervals over 1 week were recorded for each participant.

RESULTS

Participants averaged 3063+/-1893 steps per day. Strong agreement (gamma> or =0.7) between self-reported and measured activity was found for only 34% of participants between the hours of 9:00 am to 9:00 pm. The measured and self-reported proportion of time spent in various states of activity also showed poor agreement (rest, r=.41; low level activity, r=.39; medium level, r=.26; high level, r=.40). There was no bias toward either over- or under-reporting.

CONCLUSIONS

The majority of participants were unable to accurately self-report their activity levels (sleep excluded) as compared with measured activity levels. This may have important implications for prescribing appropriate prosthetics and for clinicians who provide patients with advice on promoting health.