Impact of physical activity during pregnancy and postpartum on chronic disease risk. Med Sci Sports Exerc. 2006;38:989-1006. [PMID: 16672855 DOI: 10.1249/01.mss.0000218147.51025.8a]

Association of physical activity and sedentary behavior with biological markers among U.S. pregnant women

BACKGROUND

To examine the association between objectively measured light-intensity and moderate-to-vigorous-intensity physical activity (MVPA), sedentary behaviors, and biological markers in a national sample of U.S. pregnant women, as few studies have examined these relationships among this population.

METHODS

The sample of noninstitutionalized U.S. civilians was selected by a complex, multistage probability design. Data from the 2003-2006 National Health and Examination Survey were used. Two hundred six pregnant women were included in the data analysis. Physical activity and sedentary data were objectively measured via accelerometry (ActiGraph 7164). Biomarker data was obtained in the mobile examination center from urine, blood samples, blood pressure, and anthropometric measurements. Urine and blood samples were obtained to determine pregnancy status, C-reactive protein (CRP), high-density lipoprotein (HDL) cholesterol, total cholesterol, and cotinine as well as fasting glucose, fasting triglycerides, and fasting low-density lipoprotein (LDL) cholesterol data. Multivariable regression was employed to examine the association between physical activity, sedentary behavior, and biomarker levels.

RESULTS

There was a positive association between sedentary behavior and CRP levels (beta coefficient [b]=0.001, p=0.02) and LDL cholesterol (b=0.12, p=0.02). There was an inverse association between light-intensity physical activity and CRP (b=-0.003; p=0.008) and diastolic blood pressure (b=-0.03; p=0.02), with those engaging in higher levels of MVPA having higher HDL cholesterol (b=6.7; p=0.01).

CONCLUSION

Physical activity and sedentary behavior were favorably associated with various biomarkers among pregnant women, suggesting that healthcare providers should encourage pregnant women to participate in safe forms of physical activity behaviors while also reducing their amount of time spent in sedentary behaviors.

Mother's exercise during pregnancy programmes vasomotor function in adult offspring

The intrauterine environment is influenced by maternal behaviour and programmes atherosclerotic disease susceptibility in offspring. The aim of this investigation was to test the hypothesis that mothers' exercise during pregnancy improves endothelial function in 3-, 5- and 9-month-old porcine offspring. The pregnant sows in the exercise group ran for an average of 39.35 ± 0.75 min at 4.81 ± 0.35 km h(-1) each day for 5 days per week for all but the last week of gestation. This induced a significant reduction in resting heart rate (exercised group, 89.3 ± 3.5 beats min(-1); sedentary group, 102.1 ± 3.1 beats min(-1); P < 0.05) but no significant differences in gestational weight gain (65.8 ± 2.1 versus 63.3 ± 1.9%). No significant effect on bradykinin-induced vasorelaxation with and without l-NAME was observed. A significant main effect was identified on sodium nitroprusside-induced vasorelaxation (P = 0.01), manifested by a reduced response in femoral arteries of all age groups from exercised-trained swine. Nitric oxide signalling was not affected by maternal exercise. Protein expression of MYPT1 was reduced in femoral arteries from 3-month-old offspring of exercised animals. A significant interaction was observed for PPP1R14A (P < 0.05) transcript abundance and its protein product CPI-17. In conclusion, pregnant swine are able to complete an exercise-training protocol that matches the current recommendations for pregnant women. Gestational exercise is a potent stimulus for programming vascular smooth muscle relaxation in adult offspring. Specifically, exercise training for the finite duration of pregnancy decreases vascular smooth muscle responsiveness in adult offspring to an exogenous nitric oxide donor.

Green space, social inequalities and neonatal mortality in France

Background

Few studies have considered using environmental amenities to explain social health inequalities.

Nevertheless, Green spaces that promote good health may have an effect on socioeconomic health inequalities. In developed countries, there is considerable evidence that green spaces have a beneficial effect on the health of urban populations and recent studies suggest they can have a positive effect on pregnancy outcomes. To investigate the relationship between green spaces and the spatial distribution of infant mortality taking account neighborhood deprivation levels.

Methods

The study took place in Lyon metropolitan area, France. All infant deaths that occurred between 2000 and 2009 were geocoded at census block level. Each census block was assigned greenness and socioeconomic deprivation levels. The spatial–scan statistic was used to identify high risk cluster of infant mortality according to these neighborhood characteristics.

Results

The spatial distribution of infant mortality was not random with a high risk cluster in the south east of the Lyon metropolitan area (p<0.003). This cluster disappeared (p=0.12) after adjustment for greenness level and socioeconomic deprivation, suggesting that these factors explain part of the spatial distribution of infant mortality. These results are discussed using a conceptual framework with 3 hypothetical pathways by which green spaces may have a beneficial effect on adverse pregnancy outcomes: (i) a psychological pathway, (ii) a physiological disruption process and (iii) an environmental pathway.

Conclusions

These results add some evidence to the hypothesis that there is a relationship between access to green spaces and pregnancy outcomes but further research is required to confirm this.

Relationship of Past-Pregnancy Physical Activity and Self-efficacy With Current Physical Activity and Postpartum Weight Retention

Life events unique to the perinatal period may place a woman at greater risk for decreased physical activity and increased postpartum weight retention (PPWR). Study purposes were to determine a) the relationship between women’s postpartum self-efficacy (SE) to overcome perceived barriers to exercise with current and past pregnancy leisure-time physical activity (LTPA), and b) the relationship between LTPA and PPWR. A Modifiable Activity Questionnaire was used to assess current and past pregnancy LTPA (Met*h/wk) at 20 and 32 weeks gestation and 12 weeks postpartum. Current barriers to LTPA and SE were assessed via the Perceived Barriers Efficacy Questionnaire. Top three barrier values were averaged to obtain an overall SE score for participants (N=30). Pearson correlations were run between LTPA, PPWR and SE scores. ANOVA was used to compare PPWR between women who did and did not meet LTPA guidelines of 7.5 MET*h/wk. The top three barriers to LTPA were time, motivation, and childcare. Positive correlations (p≤0.01) were found between SE levels and LTPA at all time periods of interest. LTPA was inversely related to PPWR. Relationships between SE, LTPA, and PPWR helped validate the need to promote perinatal PA, to aid long term weight management.

Guidelines for Physical Activity during Pregnancy: Comparisons From Around the World

INTRODUCTION

Women attain numerous benefits from physical activity during pregnancy. However, due to physical changes that occur during pregnancy, special precautions are also needed. This review summarizes current guidelines for physical activity among pregnant women worldwide.

METHODS

We searched PubMed (MedLINE) for country-specific governmental and clinical guidelines on physical activity during pregnancy through the year 2012. We cross-referenced with articles referring to guidelines, with only the most recent included. An abstraction form was used to extract key details and summarize.

RESULTS

In total, 11 guidelines were identified from nine countries (Australia, Canada, Denmark, France, Japan, Norway, Spain, United Kingdom, United States). Most guidelines supported moderate intensity physical activity during pregnancy (10/11) and indicated specific frequency (9/11) and duration/time (9/11) recommendations. Most guidelines provided advice on initiating an exercise program during pregnancy (10/11). Six guidelines included absolute and relative contraindications to exercise. All guidelines generally ruled-out sports with risks of falls, trauma, or collisions. Six guidelines included indications for stopping exercise during pregnancy.

CONCLUSION

This review contrasted pregnancy-related physical activity guidelines from around the world, and can help to inform new guidelines as they are created or updated, and facilitate the development of a worldwide guideline.

Clinical guidelines for occupational lifting in pregnancy: evidence summary and provisional recommendations

Empirically based lifting criteria established by the National Institute for Occupational Safety and Health (NIOSH) to reduce the risk of overexertion injuries in the general US working population were evaluated for application to pregnant workers. This report proposes criteria to guide decisions by medical providers about permissible weights for lifting tasks performed at work over the course of an uncomplicated pregnancy. Our evaluation included an extensive review of the literature linking occupational lifting to maternal and fetal health. Although it has been 29 years since the American Medical Association's Council on Scientific Affairs published its report on the Effects of Pregnancy on Work Performance, these guidelines continue to influence clinical decisions and workplace policies. Provisional clinical guidelines derived from the NIOSH lifting criteria that account for recent evidence for maternal and fetal health are presented and aim to improve the standard of care for pregnant workers.

The effects of physical activity and physical activity plus diet interventions on body weight in overweight or obese women who are pregnant or in postpartum: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

To review the effectiveness of physical activity (PA) and PA plus diet interventions in managing weight among overweight or obese (OW/OB) pregnant or postpartum women.

METHODS

Four databases were searched for randomized controlled studies published between January 2000 and December 2011 that reported weight change outcomes of PA interventions in OW/OB pregnant or postpartum women. PA alone as well as PA plus diet interventions were included.

RESULTS

Of 681 abstracts identified, 11 were included (7 trials with pregnant women and 4 trials with postpartum women). Overall, we found that PA interventions were effective for OW/OB pregnant as well as postpartum women. On average, pregnant women in the intervention groups gained 0.91kg less (95% CI: -1.76, -0.06) compared with those in the usual care groups. Postpartum women in the intervention groups significantly lost more body weight (-1.22kg; 95% CI: -1.89, -0.56) than those in the control groups. In the subgroup analyses by PA intervention types, supervised PA plus diet interventions were the most effective.

CONCLUSIONS

PA plus diet interventions may require more than advice; supervised PA programs or personalized prescription/goals are needed to prevent excessive weight gain for OW/OB pregnant women and excessive weight retention for OW/OB postpartum women.

Perceived benefits and barriers to leisure-time physical activity during pregnancy in previously inactive and active women

This study compared perceived benefits and barriers to leisure-time physical activity during pregnancy among women who were insufficiently active or inactive before pregnancy. Eighty-two pregnant women completed questionnaires assessing leisure-time physical activity benefits/barriers, exercise self-efficacy, social support, depressed mood, pre-pregnancy and current physical activity and fatigue. Multivariable regression analyses identified factors associated with exercise benefits/barriers for the two pre-pregnancy leisure-time physical activity groups. Both pre-pregnancy leisure-time physical activity groups reported more benefits than barriers to exercise during pregnancy. Previously inactive women reported fewer perceived benefits and greater perceived barriers to leisure-time physical activity during pregnancy. Higher self-efficacy for exercise during pregnancy was significantly associated with greater benefits of leisure-time physical activity during pregnancy for both groups. Less family support for exercise and lower self-efficacy for exercise were significantly related to greater leisure-time physical activity barriers during pregnancy for previously inactive women. Lower self-efficacy for exercise, higher depressed mood scores, and younger age were associated with greater leisure-time physical activity barriers for active women. Findings suggest that the intensities of perceived leisure-time physical activity benefits and barriers during pregnancy differ for women, depending on their pre-pregnancy leisure-time physical activity status. Consideration of pre-pregnancy leisure-time physical activity status may thus be important when tailoring strategies to overcome barriers to promote initiation and maintenance of physical activity during pregnancy.

Weight loss before conception: A systematic literature review

The prevalence of overweight and obesity in women has increased during the last decades. This is a serious concern since a high BMI before conception is an independent risk factor for many adverse outcomes of pregnancy. Therefore, dietary counseling, intended to stimulate weight loss in overweight and obese women prior to conception has recently been recommended. However, dieting with the purpose to lose weight may involve health risks for mother and offspring. We conducted a systematic literature review to identify papers investigating the effects of weight loss due to dietary interventions before conception. The objective of this study is to assess the effect of weight loss prior to conception in overweight or obese women on a number of health-related outcomes in mother and offspring using studies published between January 2000 and December 2011. Our first literature search produced 486 citations and, based on predefined eligibility criteria, 58 were selected and ordered in full text. Two group members read each paper. Fifteen studies were selected for quality assessment and two of them were considered appropriate for inclusion in evidence tables. A complementary search identified 168 citations with four papers being ordered in full text. The two selected studies provided data for overweight and obese women. One showed a positive effect of weight loss before pregnancy on the risk of gestational diabetes and one demonstrated a reduced risk for large-for-gestational-age infants in women with a BMI above 25 who lost weight before pregnancy. No study investigated the effect of weight loss due to a dietary intervention before conception. There is a lack of studies on overweight and obese women investigating the effect of dietary-induced weight loss prior to conception on health-related variables in mother and offspring. Such studies are probably lacking since they are difficult to conduct. Therefore, alternative strategies to control the body weight of girls and women of reproductive age are needed.

The Maternal Obesity Management (MOM) Trial Protocol: a lifestyle intervention during pregnancy to minimize downstream obesity

BACKGROUND

Maternal obesity and/or high gestational weight gain (GWG) are associated with downstream child obesity. Pregnancy represents a critical period for prevention as women are highly motivated and more receptive to behavior change.

OBJECTIVE

This pilot study was developed to test the feasibility of intervening with the mother, specifically keeping her GWG within the Institute of Medicine (IOM) limits, with the intended target of preventing obesity in her child downstream. We are testing the practicality of delivering a structured physical activity and nutrition intervention to pregnant women during gestation and then following mom and baby to 24 months of age.

STUDY DESIGN

This study is a two-arm, parallel group, randomized controlled trial being conducted in Ottawa. Pregnant women, with pregravid BMI >18.5, between 12 and 20 weeks gestation are randomized to one of two groups: intervention (n=30) who receive the MOM trial Handbook (guide to healthy gestation) plus a structured physical activity and nutrition program, or a standard clinical care control group (n=30). The intervention lasts 25-28 weeks (6 months) depending on anticipated delivery date, with follow-up assessment on mother and child at 3, 6, 12 and 24 months post-delivery.

SIGNIFICANCE

Pregnancy, a critical time of growth, development and physiological change, provides an opportunity for early lifestyle intervention. The goal of identifying an effective lifestyle program for the gestational period that leads to healthy fetal development and subsequently normal weight offspring, less likely to develop obesity and its co-morbidities, is unique and could possibly attenuate the inter-generational cycle of obesity.

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.

Physical activity during pregnancy and postpartum depressive symptoms

OBJECTIVE

to examine the associations between total and domain-specific moderate-to-vigorous physical activity (MVPA) during pregnancy and postpartum depressive symptoms.

DESIGN

a prospective cohort study.

PARTICIPANTS

data were obtained from 652 women recruited from prenatal clinics at University of North Carolina Hospitals during 2001-2005 for the Pregnancy, Infection, and Nutrition (PIN) Postpartum Study.

MEASUREMENTS

MVPA measured at 17-22 and 27-30 weeks' gestation was investigated as a predictor of depressive symptoms assessed with the Edinburgh Postnatal Depression Scale at 3 months postpartum.

FINDINGS

total MVPA was not associated with depressive symptoms when using either 17-22 weeks' gestation or 27-30 weeks' gestation MVPA measures. In general, there were minimal associations for domain-specific MVPA. The direction of associations between depressive symptoms and work, adult and child care, and outdoor household MVPAs differed by time of measurement.

KEY CONCLUSIONS

the association between physical activity and postpartum depressive symptoms may differ with the timing of assessment. Additional studies (i.e. with a larger sample of women or a sample of at-risk women) following women throughout pregnancy and postpartum are needed to explore differences in the influence of physical activity on depressive symptoms.

IMPLICATIONS FOR PRACTICE

assessment of potential risk factors for elevated depressive symptoms, such as participation levels in different types of physical activity, throughout pregnancy may assist in determining who may be susceptible to postpartum depression.

Changes in physical activity among postpartum overweight and obese women: results from the KAN-DO Study

Few studies have assessed physical activity at multiple time points in the postpartum period or used both self-reported and objective measures of assessment. The purpose of this study was to describe physical activity and sedentary behavior at two time points in a cohort of overweight or obese postpartum women using both self-reported and objective measures. In total, 132 women completed physical activity assessments at a median of 24 weeks postpartum and again approximately 10 months later. At both time points, women wore an Actical accelerometer for one week and completed the Kaiser Physical Activity Survey. Adjusted Poisson regression models were used to determine whether physical activity changed over time for the cohort. Overall counts per minute and moderate to vigorous physical activity increased from baseline to 10 months later, although the absolute levels were modest (median 6.9 to 8.8 minutes/day). A median of 64%-71% at baseline and 63%-67% at follow-up of their monitored times were sedentary. More intensive interventions are needed to help postpartum women integrate physical activity and reduce sedentary behavior. [Supplementary material is available for this article. Go to the publisher's online edition of Women & Health for the following resource: three figures that show the distribution of physical activity and sedentary behavior by study periods among control participants].

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.

Using a combined protection motivation theory and health action process approach intervention to promote exercise during pregnancy

Despite the benefits of exercise during pregnancy, many expectant mothers are inactive. This study examined whether augmenting a protection motivation theory (PMT) intervention with a Health Action Process Approach can enhance exercise behavior change among pregnant women. Sixty inactive pregnant women were randomly assigned to one of three treatment groups: PMT-only, PMT + action-planning, and PMT + action-and-coping-planning. Week-long objective (accelerometer) and subjective (self-report) exercise measures were collected at baseline, and at 1- and 4-weeks post-intervention. Repeated-measures ANOVAs demonstrated that while all participants reported increased exercise from baseline to 1-week post-intervention, participants in both planning groups were significantly more active (p < .001) than those in the PMT-only group by 4-weeks post-intervention (η (2) = .13 and .15 for accelerometer and self-report data, respectively). In conclusion, augmenting a PMT intervention with action or action-and-coping-planning can enhance exercise behavior change in pregnant women.

Evaluation of the 'healthy start to pregnancy' early antenatal health promotion workshop: a randomized controlled trial

BACKGROUND

Pregnancy is an ideal time to encourage healthy lifestyles as most women access health services and are more receptive to health messages; however few effective interventions exist. The aim of this research was to deliver a low-intensity, dietitian-led behavior change workshop at a Maternity Hospital to influence behaviors with demonstrated health outcomes.

METHODS

Workshop effectiveness was evaluated using an RCT; 'usual care' women (n = 182) received a nutrition resource at their first antenatal visit and 'intervention' women also attended a one-hour 'Healthy Start to Pregnancy' workshop (n = 178). Dietary intake, physical activity levels, gestational weight gain knowledge, smoking cessation, and intention to breastfeed were assessed at service-entry and 12 weeks later. Intention-to-treat (ITT) and per-protocol (PP) analyses examined change over time between groups.

RESULTS

Approximately half (48.3%) the intervention women attended the workshop and overall response rate at time 2 was 67.2%. Significantly more women in the intervention met pregnancy fruit guidelines at time 2 (+4.3%, p = 0.011) and had a clinically-relevant increase in physical activity (+27 minutes/week) compared with women who only received the resource (ITT). Women who attended the workshop increased their consumption of serves of fruit (+0.4 serves/day, p = 0.004), vegetables (+0.4 serves/day, p = 0.006), met fruit guidelines (+11.9%, p < 0.001), had a higher diet quality score (p = 0.027) and clinically-relevant increases in physical activity (+21.3 minutes/week) compared with those who only received the resource (PP).

CONCLUSIONS

The Healthy Start to Pregnancy workshop attendance facilitates improvements in important health behaviors. Service changes and accessibility issues are required to assist women's workshop attendance to allow more women to benefit from the workshop's effects.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ACTRN12611000867998.

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.

More Active Mums in Stirling (MAMMiS): a physical activity intervention for postnatal women. Study protocol for a randomized controlled trial

Background

Many postnatal women are insufficiently physically active in the year after childbirth and could benefit from interventions to increase activity levels. However, there is limited information about the efficacy, feasibility and acceptability of motivational and behavioral interventions promoting postnatal physical activity in the UK.

Methods

The MAMMiS study is a randomized, controlled trial, conducted within a large National Health Service (NHS) region in Scotland. Up to 76 postnatal women will be recruited to test the impact of two physical activity consultations and a 10-week group pram-walking program on physical activity behavior change. The intervention uses evidence-based motivational and behavioral techniques and will be systematically evaluated using objective measures (accelerometers) at three months, with a maintenance measure taken at a six-month follow-up. Secondary health and well-being measures and psychological mediators of physical activity change are included.

Discussion

The (MAMMiS study will provide a test of a theoretical and evidence-based physical activity behavior change intervention for postnatal women and provide information to inform future intervention development and testing within this population.

Trial registration

Current Controlled Trials ISRCTN79011784

Exercise for pregnant women for preventing gestational diabetes mellitus

BACKGROUND

Gestational diabetes mellitus (GDM) affects a significant number of women each year. GDM is associated with a wide range of adverse outcomes for women and their babies. Recent observational studies have found physical activity during normal pregnancy decreases insulin resistance and therefore might help to decrease the risk of developing GDM.

OBJECTIVES

To assess the effects of physical exercise for pregnant women for preventing glucose intolerance or GDM.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (2 April 2012), ClinicalTrials.gov (2 April 2012) and the WOMBAT Perinatal Trials Registry (2 April 2012).

SELECTION CRITERIA

Randomised and cluster-randomised trials assessing the effects of exercise for preventing pregnancy glucose intolerance or GDM.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, extracted data and assessed the risk of bias of included studies.

MAIN RESULTS

We included five trials with a total of 1115 women and their babies (922 women and their babies contributed outcome data). Four of the five included trials had small sample sizes with one large trial that recruited 855 women and babies. All five included trials had a moderate risk of bias. When comparing women receiving additional exercise interventions with those having routine antenatal care, there was no significant difference in GDM incidence (three trials, 826 women, risk ratio (RR) 1.10, 95% confidence interval (CI) 0.66 to 1.84), caesarean section (two trials, 934 women, RR 1.33, 95% CI 0.97 to 1.84) or operative vaginal birth (two trials, 934 women, RR 0.83, 95% CI 0.58 to 1.17). No trial reported the infant primary outcomes prespecified in the review.None of the five included trials found significant differences in insulin sensitivity. Evidence from one single large trial suggested no significant difference in the incidence of developing pregnancy hyperglycaemia not meeting GDM diagnostic criteria, pre-eclampsia or admission to neonatal ward between the two study groups. Babies born to women receiving exercise interventions had a non-significant trend to a lower ponderal index (mean difference (MD) -0.08 gram x 100 m(3), 95% CI -0.18 to 0.02, one trial, 84 infants). No significant differences were seen between the two study groups for the outcomes of birthweight (two trials, 167 infants, MD -102.87 grams, 95% CI -235.34 to 29.60), macrosomia (two trials, 934 infants, RR 0.91, 95% CI 0.68 to 1.22), or small-for-gestational age (one trial, 84 infants, RR 1.05, 95% CI 0.25 to 4.40) or gestational age at birth (two trials, 167 infants, MD -0.04 weeks, 95% CI -0.37 to 0.29) or Apgar score less than seven at five minutes (two trials, 919 infants, RR 1.00, 95% CI 0.27 to 3.65). None of the trials reported long-term outcomes for women and their babies. No information was available on health services costs.

AUTHORS' CONCLUSIONS

There is limited randomised controlled trial evidence available on the effect of exercise during pregnancy for preventing pregnancy glucose intolerance or GDM. Results from three randomised trials with moderate risk of bias suggested no significant difference in GDM incidence between women receiving an additional exercise intervention and routine care.Based on the limited data currently available, conclusive evidence is not available to guide practice. Larger, well-designed randomised trials, with standardised behavioural interventions are needed to assess the effects of exercise on preventing GDM and other adverse pregnancy outcomes including large-for-gestational age and perinatal mortality. Longer-term health outcomes for both women and their babies and health service costs should be included. Several such trials are in progress. We identified another seven trials which are ongoing and we will consider these for inclusion in the next update of this review.

The potential impact of physical activity during pregnancy on maternal and neonatal outcomes

INTRODUCTION

Pregnancy is a critical period of body weight regulation. Maternal obesity and excessive gestational weight gain have become increasingly common and contribute to poor obstetrical outcomes for mother and baby. Regular participation in physical activity may improve risk profiles in pregnant women.

PURPOSE AND METHODS

Our objectives were to provide an overview of maternal-fetal exercise physiology, summarize current evidence on the effects of physical activity during pregnancy on maternal-fetal outcomes, and review the most recent clinical practice guidelines. In addition, we summarize the findings in the context of the current obesity epidemic and discuss implications for clinical practice. A literature review was completed in which we queried OVID (Medline), EMBASE, and PSYCHINFO databases with title words "exercise or physical activity" and "pregnancy or gestation" from 1950 to March 1, 2010. A total of 212 articles were selected for review.

RECOMMENDATIONS

Care providers should recommend physical activity to most pregnant women (i.e., those without contraindications) and view participation as a safe and beneficial component of a healthy pregnancy.

TARGET AUDIENCE

Obstetricians & Gynecologists and Family Physicians.

LEARNING OBJECTIVES

After participating in this CME activity, physicians should be better able to classify the potential impact of physical activity on maternal glycemic control and fetal growth outcomes. Assess maternal lifestyle and provide recommendations on appropriate gestational weight gain, evaluate pregnant women for contraindications to physical activity participation, make individualized recommendations for exercise participation, and educate patients on the merits of physical activity for health benefit.

Impacto da orientação para a prática regular de atividade física dois anos após o parto

OBJETIVOS: avaliar as modificações na prática de atividade física (AF) e as barreiras para adoção de um estilo de vida saudável em mulheres que receberam orientações nutricionais e de AF durante a gestação e no primeiro ano após o parto. MÉTODOS: estudo de coorte com 57 mulheres (Grupo Controle = 29 e Grupo Intervenção = 28), e idade média igual a 28 (±6) anos. As informações foram obtidas através de entrevistas em visita domiciliar (durante a intervenção) e inquérito telefônico (um ano após o término da intervenção), utilizou-se questionário de AF. Para análise das barreiras foi realizada uma entrevista semiestruturada com questões abertas, as quais foram codificadas e agrupadas para análise dos dados. Foram realizados testes de qui-quadrado, Mann-Whitney U e Friedman. RESULTADOS: aos seis meses, apenas 30% das mulheres do grupo Intervenção realizavam AF no lazer pelo menos 120 minutos por semana, contra 10% do grupo Controle, reduzindo para 18% e 4%, respectivamente, dois anos após o parto. As principais barreiras à prática de AF regular foram: falta de tempo (44%), cuidado com os filhos (37%), trabalho (21%), afazeres domésticos (21%) e comodismo (26%). CONCLUSÕES: futuros programas devem priorizar a aquisição de conhecimento, visando à adoção de um estilo de vida ativo no pós-parto, considerando as barreiras maternas.

Impact of a health promotion intervention on maternal depressive symptoms at 15 months postpartum

Given that diet, physical activity, and social support are associated with depression, we examined whether a health promotion intervention designed to modify these factors in low-income, postpartum women would reduce depressive symptoms. This study used a randomized, controlled design to examine the effect of the Just for You (JFY) Program, an educational intervention promoting healthy lifestyles through home visits by nutrition paraprofessionals and motivational telephone counseling, on postpartum depressive symptoms. A total of 679 women income-eligible for the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) were recruited at 6-20 weeks post delivery and randomized to Usual WIC Care or JFY. Using an intention-to-treat analysis, the authors modeled depressive symptoms on the Center for Epidemiologic Studies Depression Scale (CES-D) among 403 women (59%) completing follow-up at a mean of 15 months infant age, adjusting for baseline CES-D, age, household income and randomization strata (body mass index (BMI), race/region). As a secondary analysis, the authors evaluated potential mediators related to social support and self-efficacy to change one or more health behaviors targeted by the intervention. Women randomized to JFY reported 2.5 units lower CES-D score (P = 0.046) compared with those receiving Usual WIC Care alone. This relationship was attenuated by change in self-efficacy (β = -2.3; P = 0.065), suggesting this construct may partially have mediated the effect of JFY on maternal depressive symptoms. A health promotion intervention delivered through home visits and telephone calls can reduce depressive symptoms at 15 months postpartum among low-income, ethnically diverse women.

Can physical activity reduce excessive gestational weight gain? Findings from a Chinese urban pregnant women cohort study

BACKGROUND

Excessive gestational weight gain (GWG) poses negative impact on mothers and their children. It is important to understand the modifiable lifestyle factors associated with excessive GWG during pregnancy to guide future public health practice.

AIM

To investigate the association between physical activity during pregnancy and GWG of Chinese urban pregnant women.

METHODS

A pregnant women cohort was established between 2005 and 2007 in Changzhou, China. Physical activity levels of pregnant women were assessed using pedometer in the 2nd and 3rd trimester, respectively. According to step counts, pregnant women were categorized into 4 different physical activity groups: Sedentary, Low Active, Somewhat Active and Active. The pregnant women were followed for eligibility and data collection from the 2nd trimester to delivery. Multiple linear regression and multiple binary logistic model were applied to determine the association between physical activity and GWG.

RESULTS

Physical activity levels and GWG of 862 pregnant women were assessed, among them 473 (54.9%) experienced excessive GWG. The adjusted odds ratio (OR) was 0.59 (95%CI: 0.36 ~ 0.95) for excessive GWG in the Active group during the 2nd trimester and 0.66 (95%CI: 0.43 ~ 1.00) in the Somewhat Active group during the 3rd trimester, compared with the Sedentary group respectively. In the last two trimesters, the Active group had 1.45 kg less GWG, than the Sedentary group. The ORs of excessive GWG decreased with the increased level of physical activity (P < 0.05).

CONCLUSION

This study suggests that pregnant women being physically active have less weight gain during pregnancy.

Leisure-time physical activity in pregnancy and the birth weight distribution: where is the effect?

BACKGROUND

Leisure-time physical activity (LTPA) is recommended during pregnancy and has been associated with lower risk of delivering a large infant. We sought to characterize the effect of LTPA across the entire birth weight distribution.

METHODS

Women enrolled in the Pregnancy Outcomes and Community Health (POUCH) Study (1998-2004) were followed-up in 2007. Follow-up efforts were extensive for a subcohort and minimal for the remainder (nonsubcohort). Thus, 596 subcohort and 418 nonsubcohort women who delivered at term participated. Offspring were categorized as small-, appropriate-, or large-for-gestational-age (SGA, AGA, and LGA, respectively) based on gender and gestational age-specific birth weight z-scores (BWz). At follow-up, women recalled pregnancy LTPA and were classified as inactive, insufficiently active or meeting LTPA recommendations. Linear, logistic, and quantile regression analyses were conducted separately by subcohort status.

RESULTS

Meeting LTPA recommendations decreased odds of LGA significantly among the nonsubcohort (aOR = 0.30, 95% CI: 0.14-0.64) and nonsignificantly among the subcohort (aOR = 0.68, 95% CI: 0.34-1.34). In quantile regression, meeting LTPA recommendations reduced BWz among the upper quantiles in the nonsubcohort.

CONCLUSIONS

LTPA during pregnancy lowered odds of LGA and reduced BWz among the upper quantiles, without shifting the entire distribution. LTPA during pregnancy may be useful for reducing risks of large fetal size.

Accuracy of physical activity assessment during pregnancy: an observational study

Background

Prenatal physical activity may improve maternal and infant health and lower future disease risk for both mother and baby; however, very few physical activity assessment methods have been validated for use during pregnancy. The purpose of this study was to evaluate the accuracy of a subjective physical activity record (PAR) and an objective activity monitor, against a reference standard to quantify moderate and vigorous physical activity (MVPA) in pregnant women. The reference standard was based on participant interviews to determine if a woman was an exerciser and confirmed with information obtained from the PAR and a heart rate monitor.

Methods

Fifty-two pregnant women completed a physical activity record (PAR) and wore a SenseWear^® Mini Armband (SWA) activity monitor over a 7-day period at 18 weeks gestation. Total minutes spent in MVPA were totaled from both modalities and evaluated against the reference standard using contingency analysis and Pearson's chi-square test to evaluate the number of women meeting minimum prenatal physical activity recommendations (at least 3, 30 minute sessions of exercise per week). Both modalities were also tested individually and collectively to assess their ability as indicators of activity using empirically determined cut-offs as indicated by receiver-operator characteristic curves. These experimentally-derived criteria were also tested with Pearson's chi-square test.

Results

According to the reference standard, 13 of 52 participants (25%) met the criterion of 3, 30 minute sessions of volitional, moderate-intensity activity. When compared to the reference standard, both the PAR and SWA overestimated exercise status; 42 (81%) and 52 (100%) participants, respectively, achieved 90 minutes of MVPA (P < 0.0001 for both comparisons). Single-modality predictors of MVPA did not show a significant correlation. A composite predictor of MVPA offered the most favorable option for sensitivity and specificity (true positives, n = 8 and true negatives, n = 36) using cut-offs of 280 and 385 minutes/week for the PAR and SWA, respectively.

Conclusion

Compared to the reference standard, time spent in MVPA obtained from the PAR or SWA overestimated the prevalence of women meeting prenatal exercise recommendations. The most accurate predictor of women meeting current prenatal exercise guidelines was identified by using the PAR and SWA collectively.

Gestational diabetes: development of an early risk prediction tool to facilitate opportunities for prevention

BACKGROUND AND AIM

In the setting of advancing maternal age, escalating obesity and increasing Gestational Diabetes Mellitus (GDM) rates, we aimed to develop a novel risk prediction tool to identify high-risk women in early pregnancy, specifically to facilitate targeted antenatal prevention of GDM.

METHODS

In this retrospective, observational study, first-trimester data collected routinely by midwifery staff in 4276 women attending a large tertiary hospital in 2007/2008 was analysed to examine predictive factors for GDM. GDM was diagnosed with a 28-week oral glucose tolerance test. The data set included a derivation group (n=2880, from 2007 deliveries) and a validation group (n = 1396, from 2008). Multivariate analysis generated a scoring system.

RESULTS

GDM was significantly correlated with a number of factors: past history of GDM, increasing maternal age and body mass index, Asian descent and family history of diabetes. Validation group clinical scores achieved a sensitivity of 61.3% and specificity of 71.4% for differentiating women according to their risk of developing GDM.

CONCLUSIONS

Risk factors for GDM are easily identified at the first-trimester midwifery hospital booking visit. A risk prediction tool, derived from risk factors in early pregnancy, identifies women at high risk of GDM. This represents a novel approach to facilitate targeted early intervention with the potential to prevent development of, or ameliorate, GDM.

Safety and efficacy of supervised strength training adopted in pregnancy

OBJECTIVE

Describe safety and efficacy of a supervised, low-to-moderate intensity strength training program adopted during pregnancy among women at increased risk for back pain.

METHODS

32 women adopted strength training twice per week for 12 weeks. Data on musculoskeletal injuries, symptoms, blood pressure, and the absolute external load used for 5 of 6 exercises were obtained during each session. A submaximal lumbar extension endurance exercise test was performed at weeks 5, 10, and 13.

RESULTS

The mean (± SD) exercise session attendance rate was 80.5% (± 11.3%). No musculoskeletal injuries occurred. Potentially adverse symptoms (eg, dizziness) were infrequent (2.1% of sessions). Repeated-measures ANOVA showed large increases in the external load across 12 weeks (all P values < .001) and the percentage increases in external load from weeks 1 to 12 were 36% for leg press, 39% for leg curl, 39% for lat pull down, 41% for lumbar extension and 56% for leg extension. Training was associated with a 14% increase in lumbar endurance. Blood pressure was unchanged following acute exercise sessions and after 12 weeks of exercise training.

CONCLUSION

The adoption of a supervised, low-to-moderate intensity strength training program during pregnancy can be safe and efficacious for pregnant women.

Primary prevention of gestational diabetes mellitus and large-for-gestational-age newborns by lifestyle counseling: a cluster-randomized controlled trial

BACKGROUND

Our objective was to examine whether gestational diabetes mellitus (GDM) or newborns' high birthweight can be prevented by lifestyle counseling in pregnant women at high risk of GDM.

METHOD AND FINDINGS

We conducted a cluster-randomized trial, the NELLI study, in 14 municipalities in Finland, where 2,271 women were screened by oral glucose tolerance test (OGTT) at 8-12 wk gestation. Euglycemic (n = 399) women with at least one GDM risk factor (body mass index [BMI] ≥ 25 kg/m(2), glucose intolerance or newborn's macrosomia (≥ 4,500 g) in any earlier pregnancy, family history of diabetes, age ≥ 40 y) were included. The intervention included individual intensified counseling on physical activity and diet and weight gain at five antenatal visits. Primary outcomes were incidence of GDM as assessed by OGTT (maternal outcome) and newborns' birthweight adjusted for gestational age (neonatal outcome). Secondary outcomes were maternal weight gain and the need for insulin treatment during pregnancy. Adherence to the intervention was evaluated on the basis of changes in physical activity (weekly metabolic equivalent task (MET) minutes) and diet (intake of total fat, saturated and polyunsaturated fatty acids, saccharose, and fiber). Multilevel analyses took into account cluster, maternity clinic, and nurse level influences in addition to age, education, parity, and prepregnancy BMI. 15.8% (34/216) of women in the intervention group and 12.4% (22/179) in the usual care group developed GDM (absolute effect size 1.36, 95% confidence interval [CI] 0.71-2.62, p = 0.36). Neonatal birthweight was lower in the intervention than in the usual care group (absolute effect size -133 g, 95% CI -231 to -35, p = 0.008) as was proportion of large-for-gestational-age (LGA) newborns (26/216, 12.1% versus 34/179, 19.7%, p = 0.042). Women in the intervention group increased their intake of dietary fiber (adjusted coefficient 1.83, 95% CI 0.30-3.25, p = 0.023) and polyunsaturated fatty acids (adjusted coefficient 0.37, 95% CI 0.16-0.57, p < 0.001), decreased their intake of saturated fatty acids (adjusted coefficient -0.63, 95% CI -1.12 to -0.15, p = 0.01) and intake of saccharose (adjusted coefficient -0.83, 95% CI -1.55 to -0.11, p  =  0.023), and had a tendency to a smaller decrease in MET minutes/week for at least moderate intensity activity (adjusted coefficient 91, 95% CI -37 to 219, p = 0.17) than women in the usual care group. In subgroup analysis, adherent women in the intervention group (n = 55/229) had decreased risk of GDM (27.3% versus 33.0%, p = 0.43) and LGA newborns (7.3% versus 19.5%, p = 0.03) compared to women in the usual care group.

CONCLUSIONS

The intervention was effective in controlling birthweight of the newborns, but failed to have an effect on maternal GDM.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN33885819. Please see later in the article for the Editors' Summary.

Physical activity and depressive symptoms among pregnant women: the PIN3 study

Prenatal depression confers health risks for both mother and family. Physical activity may promote better mental health; however, few studies have examined the influence of physical activity on prenatal depression. Data from 1,220 women enrolled in the third Pregnancy, Infection, and Nutrition Study (2001-2005) were used to examine the associations between overall and domain-specific moderate-to-vigorous physical activity (MVPA) and depressive symptoms during pregnancy. Self-reported, past week physical activity assessed at 17-22 weeks' gestation was modeled in logistic regression with self-reported depressive symptoms assessed by the Center for Epidemiologic Studies-Depression Scale at 24-29 weeks' gestation. Active women with ≤2.67 h/week of total MVPA had almost half the odds of having high depressive symptoms as compared to women with no MVPA (odds ratio [OR] = 0.56, 95% confidence interval [CI] = 0.38, 0.83). Increased odds of elevated depressive symptoms were found for women participating in some but ≤2.25 h/week of adult and child care MVPA (OR = 1.84; 95% CI = 1.08, 3.11) and >1 h of indoor household MVPA (OR = 1.63, 95% CI = 0.99, 2.70) when compared to women with no MVPA. While overall MVPA may play a role in reducing the odds of developing elevated depressive symptoms, adult and child care and indoor household activities may increase it.

Antenatal depression: a rationale for studying exercise

BACKGROUND

Major depressive disorder (MDD) in pregnancy or antenatal depression poses unique treatment challenges and has serious consequences for mothers, unborn babies, and families when untreated. This review presents current knowledge on exercise during pregnancy, antidepressant effects of exercise, and the rationale for the specific study of exercise for antenatal depression.

METHOD

A systematic literature review was performed using English language articles published in Medline, PsycINFO, CINAHL, and the Cochrane Library from 1985 to January 2010.

RESULTS

There is a broad literature supporting the antidepressant effects of exercise, but a paucity of studies specifically for antenatal depression. A small number of observational studies have reported that regular physical activities improve self-esteem and reduce symptoms of anxiety and depression during pregnancy. To date, there have not been randomized controlled studies of exercise for the treatment of MDD in pregnant women.

CONCLUSIONS

Systematic studies are needed to assess exercise as a treatment alternative for MDD during pregnancy. In consideration of the benefits of exercise for the mother and baby, and the burden of depression, studies are needed to determine the role of exercise for pregnant women with depression.

Compliance with leisure-time physical activity recommendations in pregnant women

OBJECTIVE

The aim of this study was to identify the prevalence and factors associated with the performance of minimal beneficial leisure-time physical activity in the first half of pregnancy according to the criteria of the American College of Sport and Medicine (ACSM) and the American College of Obstetricians and Gynecologists (ACOG).

MATERIAL AND METHODS

This was a cross-sectional study carried out at the Maternal and Neonatal University Hospital in Granada, which services the whole population of the hospital reference area. We studied 1,175 healthy pregnant women aged over 18 years. Information about sociodemographics, lifestyles, obstetric antecedents and anthropometric variables were collected. The amount of leisure-time physical activity was quantified by assigning metabolic equivalents to each activity. The ACSM and ACOG criteria were used to define optimal physical activity in the first half of pregnancy. The frequency of compliance for both criteria was estimated. Multiple logistic regression models were fitted to study the factors associated with the recommendations.

RESULTS

Only 20.3% (95% confidence interval 15.50-26.10) of the women complied with ACOG criteria. More women complied with ACSM recommendations (70.8%, 95% confidence interval 67.5-73.8), which are less restrictive criteria. Women aged 30 years old or older and those with a university degree tended to devote more time to exercising according to both recommendations.

CONCLUSION

The prevalence of pregnant women who performed minimal beneficial leisure-time physical activity was lower with the dominant and more accepted criteria. It is necessary to encourage physical activity, mainly among those who are younger, and those with lower levels of educational attainment.

Responses of serum neurotrophic factors to exercise in pregnant and postpartum women

It was recently shown in humans that exercise affects the neurotrophic factors known to function as neurogenesis regulators. No data related to exercise and pregnancy, however, is yet available. Thus, we investigated the effects of acute exercise on pregnant women during late pregnancy and women postpartum, on the serum concentration of the brain-derived neurotrophic factor (BDNF), the insulin-like growth factor 1 (IGF-1), the vascular endothelial growth factor (VEGF), prolactin (PRL) and cortisol (COR). Twenty women with uncomplicated pregnancies underwent a graded submaximal exercise test during pregnancy (weeks 32-36 of gestation; T(1)) and postpartum (10-12 weeks after childbirth; T(2)). On two of these test days the women carried out an intensifying exercise test (25 W steps) on a cycle ergometer until a heart rate of 150 bpm was reached. Blood samples were taken in the rest period before beginning the exercise, immediately at the end of the exercise and after recovery periods of 5 and 10 min, respectively. Basal maternal IGF-1, PRL and COR were found to be higher during T(1) (p<.01), while the BDNF was higher during T(2) (p=.00). VEGF was not detectable in the serum of the pregnant women. During T(2), VEGF, which was found to be within the normal range before exercise, was at a higher level after exercise (p<.01). Exercise increased the BDNF and IGF-1 during T(1) and T(2) (p<.01). This study also shows that exercise increases the serum concentrations of IGF-1 and BDNF during pregnancy and postpartum as well as VEGF postpartum. Thus, exercise might be a beneficial lifestyle factor with therapeutic/public health implications i.e. with regard to maternal mood and cognitive performance.

Physical activity during pregnancy in a prospective cohort of British women: results from the Avon longitudinal study of parents and children

We sought to examine the levels, types, and changes of physical activity and their correlates among pregnant women. Data came from 9,889 pregnant women with due dates between April 1, 1991 and December 31, 1992 who were participants of the Avon Longitudinal Study of Parents and Children (ALSPAC) in Bristol, Avon, Southwest England. Self-reported physical activity during pregnancy was collected via questionnaires administered at 18 and 32 weeks of gestation. We found, at 18 weeks of gestation, the prevalence of engaging in physical activity that was sufficient to cause sweating for ≥ 3 h/week (referred to as strenuous physical activity) was 48.8%. This percentage was similar at 32 weeks of gestation. The most common physical activity during pregnancy reported by these women was brisk walking, followed by swimming and ante-natal exercise. In models that mutually adjusted for all characteristics examined, younger women, women in lower social classes, those not employed during pregnancy, married and parous women (compared to those not in each of these groups) were more likely to report engaging in strenuous physical activity. After becoming pregnant, about two out of three of these women reported reducing physical activity levels at 18 weeks of gestation. In mutually adjusted models, women who were younger, fit and well, parous, and women from lower social classes (compared to those not in each of these groups) were less likely to report reducing their physical activity. Our findings provide insights that are relevant to the design of future observational and intervention studies concerned with the effects of physical activity during pregnancy on health outcomes for mothers and offspring.

Prevention of gestational diabetes: design of a cluster-randomized controlled trial and one-year follow-up

Background

Annual prevalence of gestational diabetes mellitus (GDM) is 12.5% among Finnish pregnant women. The prevalence is expected to rise with the increasing overweight among women before pregnancy. Physical activity and diet are both known to have favourable effects on insulin resistance and possibly on the risk of GDM. We aimed to investigate, whether GDM can be prevented by counseling on diet, physical activity and gestational weight gain during pregnancy.

Methods/Design

A cluster-randomized controlled trial was conducted in 14 municipalities in the southern part of Finland. Pairwise randomization was performed in order to take into account socioeconomic differences. Recruited women were at 8-12 weeks' gestation and fulfilled at least one of the following criteria: body mass index ≥ 25 kg/m², history of earlier gestational glucose intolerance or macrosomic newborn (> 4500 g), age ≥ 40 years, first or second degree relative with history of type 1 or 2 diabetes. Main exclusion criterion was pathological oral glucose tolerance test (OGTT) at 8-12 weeks' gestation. The trial included one counseling session on physical activity at 8-12 weeks' gestation and one for diet at 16-18 weeks' gestation, and three to four booster sessions during other routine visits. In the control clinics women received usual care. Information on height, weight gain and other gestational factors was obtained from maternity cards. Physical activity, dietary intake and quality of life were followed by questionnaires during pregnancy and at 1-year postpartum. Blood samples for lipid status, hormones, insulin and OGTT were taken at 8-12 and 26-28 weeks' gestation and 1 year postpartum. Workability and return to work were elicited by a questionnaire at 1- year postpartum. Linkage to the national birth register of years 2007-2009 will provide information on perinatal complications and GDM incidence among the non-participants of the study. Cost-effectiveness evaluation will be based on quality-adjusted life years. This study has received ethical approval from the Ethical board of Pirkanmaa Hospital District.

Discussion

The study will provide information on the effectiveness and cost-effectiveness of gestational physical activity and dietary counseling on prevention of GDM in a risk group of women. Also information on the prevalence of GDM and postpartum metabolic syndrome will be gained. Results on maintaining the possible health behaviour changes are important in order to prevent chronic diseases such as cardiovascular disease and diabetes.

Trial registration

The trial is registered ISRCTN 33885819

Postpartum physical activity: measuring theory of planned behavior constructs

OBJECTIVES

To produce evidence for factor validity and longitudinal invariance of scales used to examine the theory of planned behavior applied to physical activity.

METHODS

Self-report questionnaires were administered at 3- (n = 267) and 12-months (n = 333) postpartum.

RESULTS

A single-factor model fit data from the normative beliefs, perceived behavioral control, and behavioral beliefs scales. Attitude and control beliefs were found to be multidimensional. Longitudinal invariance of all scales was supported.

CONCLUSIONS

Each scale had strong validity evidence. Future research using these measures will help identify areas for intervention and reveal how changes in these constructs influence physical activity.

Aerobic exercise during pregnancy influences fetal cardiac autonomic control of heart rate and heart rate variability

BACKGROUND

Previous studies using ultrasound technology showed that fetal heart rate (HR) may be responsive to maternal aerobic exercise. Although it is recognized that cardiac autonomic control may be influenced by the intrauterine environment, little is known about how maternal exercise affects fetal heart development.

AIMS

This study tested the hypothesis that regular maternal exercise throughout gestation influences fetal cardiac autonomic control of HR and heart rate variability (HRV) when compared to fetuses of non-exercising women.

STUDY DESIGN

Magnetocardiograms (MCGs) were recorded using a dedicated fetal biomagnetometer at 28, 32 and 36 weeks gestational age (GA) from 26 regularly exercising (>30 min of aerobic exercise, 3x per week) and 35 healthy, non-exercising pregnant women. Fetal MCG was isolated and normal R-peaks were marked to derive fetal HR and HRV in the time and frequency domains. We applied a mixed-effects model to investigate the effects of exercise, GA and fetal activity state.

RESULTS

At 36 weeks GA, during the active fetal state, fetal HR was significantly lower in the exercise group (p=<0.0006). Post-hoc comparisons showed significantly increased HRV in the exercise group during the active fetal state at 36 weeks GA for both time and frequency domain measures.

CONCLUSION

These results indicate that regular maternal exercise throughout gestation results in significantly lower fetal HR and increased HRV.

Beliefs about exercise and physical activity among pregnant women

OBJECTIVE

The objective of this study was to document self-reported beliefs about physical activity and exercise among pregnant women.

METHODS

The Pregnancy, Infection, and Nutrition (PIN3) Study asked 1306 pregnant women about beliefs regarding physical activity and exercise at 27-30 weeks' gestation.

RESULTS

While 78% of women agreed that most women can continue their regular exercise during pregnancy, fewer (68%) agreed that most women who never exercised could begin an exercise program during pregnancy. Most (89%) agreed that regular exercise was better than irregular exercise during pregnancy. While almost all women agreed with the benefits of light activity (98%), fewer agreed that there were benefits with moderate (73%) or vigorous exercise (13%). Differences in beliefs were most notable by educational level, race/ethnicity, and whether they participated in regular exercise during pregnancy.

CONCLUSION

Future studies can better elucidate the reasons behind the differences in beliefs, to explore whether cultural reasons are contributing to these differences and whether tailored messages would be more effective than general educational approaches.

PRACTICE IMPLICATIONS

This study provides information to create more successful interventions to help women understand concepts regarding the safety and benefits of physical activity during pregnancy.