2019 Canadian guideline for physical activity throughout pregnancy

Physical Activity During Pregnancy Is Associated with Increased Placental FATP4 Protein Expression

Placental function is of utmost importance to ensure proper fetal development in utero. Among the placenta's many roles includes the passage of sufficient macronutrients, such as glucose, amino acids, and fatty acids, to the fetus. Macronutrients are carried from maternal circulation to the fetus across transporters within the placenta. The objective of this study was to examine the impact of (i) an acute bout of exercise and (ii) chronic exercise participation on placenta nutrient transporter expression and localization. To investigate the effect of acute exercise, pre- and post-exercise serum was collected from pregnant (n = 5) and non-pregnant (n = 5) women who underwent a moderate-intensity exercise session and used to treat BeWo cells. To assess chronic physical activity, we analyzed term placenta from women categorized as active (n = 10) versus non-active (n = 10). Protein expression and localization for the transporters GLUT1, SNAT1, and FATP4 were examined for both groups. GLUT1 expression in BeWo cells treated with serum from pregnant women was higher compared with that from non-pregnant, independent of exercise. FATP4 protein expression was elevated in the term placenta of active women. Immunohistochemistry analysis of term placenta illustrated increased staining of FATP4 in placental tissue from active women and differential staining pattern of GLUT1 depending on physical activity status. Chronic exercise during pregnancy increases the expression of placental FATP4 in vivo, suggesting greater metabolism and usage of fatty acids. Additionally, serum from pregnant women could contain factors that increase GLUT1 protein expression in vitro. BeWo cells treated with pre- and post-exercise serum from pregnant women resulted in greater GLUT1 expression compared with those treated with pre- and post-exercise serum from non-pregnant women. Physical activity appears to differentially impact key placental transporters involved in the transfer and availability of nutrients from mother to fetus. Future research ought to examine the mechanisms involved in regulating these changes and their impact on fetal growth and health.

Why can't I exercise during pregnancy? Time to revisit medical 'absolute' and 'relative' contraindications: systematic review of evidence of harm and a call to action

BACKGROUND

Clinical guidelines recommend pregnant women without contraindication engage in regular physical activity. This is based on extensive evidence demonstrating the safety and benefits of prenatal exercise. However, certain medical conditions or contraindications warrant a reduction, modification or cessation of activity due to potential health risks.

AIM

To review and evaluate the evidence related to medical disorders which may warrant contraindication to prenatal exercise.

METHODS

Online databases were searched up to 5 April 2019. Forty-four unique studies that reported data on our Population (pregnant women with contraindication to exercise), Intervention (subjective/objective measures of acute or chronic exercise), Comparator (not essential) and Outcomes (adverse maternal or fetal outcomes) were included in the review.

KEY FINDINGS

We found that the majority of medical conditions listed as contraindications were based on expert opinion; there is minimal empirical evidence to demonstrate harm of exercise and benefit of activity restriction. We identified 11 complications (eg, gestational hypertension, twin pregnancy) previously classified as contraindications where women may in fact benefit from regular prenatal physical activity with or without modifications. However, the evidence suggests that severe cardiorespiratory disease, placental abruption, vasa previa, uncontrolled type 1 diabetes, intrauterine growth restriction, active preterm labour, severe pre-eclampsia and cervical insufficiency are associated with strong potential for maternal/fetal harm and warrant classification as absolute contraindications.

CONCLUSION

Based on empirical evidence, we provide a call to re-evaluate clinical guidelines related to medical disorders that have previously been considered contraindications to prenatal exercise. Removing barriers to physical activity during pregnancy for women with certain medical conditions may in fact be beneficial for maternal-fetal health outcomes.

Overview of Physical Activity Counseling in Primary Care

Physical inactivity is a global health burden. Promoting physical activity in primary care through physical activity counseling is an effective intervention. This article provides an overview of and perspectives on physical activity counseling in primary care. The identification of physical inactivity as a health problem may increase the awareness of physical inactivity among patients and primary care providers, which will lead to an action plan. The contents of physical activity counseling should be based on evidence-based recommendations. Safety issues should be evaluated appropriately to optimize the utilization of primary care services. Physical activity counseling methods should be "tailored" for an individual using appropriate counseling methods and setting-specific resources. Multilevel barriers to physical activity counseling in primary care (i.e., healthcare providers, patients, and systems) must be addressed. Setting-specific strategies to overcome these barriers should be implemented to maximize the effectiveness of physical activity counseling in primary care.

Therapeutic Physical Exercise Post-Treatment in Breast Cancer: A Systematic Review of Clinical Practice Guidelines

Advances achieved in diagnosis and improvements in treatment for breast cancer have resulted in a favourable survival rate. Therapeutic physical exercise (TPE) is presented as an intervention strategy that seeks to improve the functional capabilities of the subject. To analyse if clinical practice guidelines recommend therapeutic physical exercise to reduce the adverse effects of treatment in breast cancer survivors, and on what level of scientific evidence are these recommendations based. This systematic review was prepared by searching nine electronic databases to identify eligible studies. Thirteen met the criteria for inclusion. The Appraisal of Guidelines for Research and Evaluation (AGREE II) scale was used to analyse the quality of Clinical Practice Guideline (CPGs). The percentages obtained ranged between 30.07% and 75.70%. Specifically, the highest degree of evidence could be found in the application of TPE to offset adverse effects leading to effects such as: an increase in the quality of life, fatigue reduction, and reduction in body weight alterations. TPE is presented as an optimal intervention strategy to alleviate the negative effects that patients with breast cancer suffer as a result of the treatments received. The level of evidence that supports this claim is very strong for the majority of the side effects analysed. However, this evidence is not always included in the clinical practice guidelines.

Determination of minimal recording period to assess resting heart rate variability during pregnancy

Traditionally, resting heart rate variability (rHRV) is measured for 10 min using the last 5 min for analyses (e.g., criterion period). It is unknown whether the measurement period can be shortened in pregnant women as there are currently no established standards. We aimed to compare shorter time segments (e.g., from the 1st to 10th minutes) of the parasympathetic index natural logarithm transformation of root mean square of successive R–R differences (Ln rMSSD) with the criterion period in pregnant and nonpregnant women. Twelve pregnant (age: 30.8 ± 3.4 years; gestational age: 20.1 ± 5.0 weeks) and 15 nonpregnant women (age: 29.8 ± 4.0 years) were included. rHRV was measured using a portable heart rate monitor for 10 min while sitting. Ln rMSSD difference/agreement between shorter time segments and criterion period was analyzed. The result observed between the 4th–5th minutes was the shortest time segment not different from/highly agreed with the criterion period in pregnant women (difference [95% confidence interval (CI)]: −0.10 [−0.22 to 0.02]/bias ± 1.96 × SD: −0.06 [−0.38 to 0.25]). In nonpregnant women, the 2nd–3rd-minute segment was the shortest with similar results (difference [95% CI]: −0.04 [−0.15 to 0.07]/bias ± 1.96 × SD: −0.03 [−0.39 to 0.32]). The Ln rMSSD was found to be stable from the 5th–10th minutes and the 3rd–10th minutes in pregnant and nonpregnant women, respectively. A shortened rHRV assessment can increase its applicability in clinical/exercise-training settings.

Novelty Ln rMSSD can be measured for 5 min in pregnant women, with the last 1-min segment analyzed. The last 1-min segment from 3 min can be used for rHRV measurement in nonpregnant women. The shortened rHRV assessment can facilitate its applicability in clinical/exercise-training settings.

Spotlight on the fetus: how physical activity during pregnancy influences fetal health: a narrative review

Before and during pregnancy, women often aim to improve their lifestyle so as to provide a healthier environment for their developing child. It remains unresolved, however, as to whether physical activity (PA) during pregnancy poses a possible risk or whether it might even have beneficial effects on the developing child. There is increasing evidence that PA during pregnancy is indeed beneficial to maternal physiological and psychological health and that it is generally not detrimental to the fetal cardiovascular system and neuronal function in the developing child. This also led to international recommendations for PAs during pregnancy. In the current review, we aimed to comprehensively assess the evidence of beneficial and harmful effects of maternal PA, including high-performance sports, on fetal development. The different mental and body-based relaxation techniques presented here are frequently performed during pregnancy. We found a considerable number of studies addressing these issues. In general, neither low key, moderate maternal PA nor relaxation techniques were observed to have a harmful effect on the developing child. However, we identified some forms of PA which could have at least a transient unfavourable effect. Notably, the literature currently available does not provide enough evidence to enable us to make a general conclusive statement on this subject. This is due to the lack of longitudinal studies on the metabolic and cognitive effects of regular PA during pregnancy and the wide diversity of methods used. In particular, the kind of PA investigated in each study differed from study to study.

Associations of Pregnancy Physical Activity with Maternal Cardiometabolic Health, Neonatal Delivery Outcomes and Body Composition in a Biethnic Cohort of 7305 Mother-Child Pairs: The Born in Bradford Study

OBJECTIVE

Physical activity is advocated for a range of benefits to the uncomplicated pregnancy. We investigated associations of mid-pregnancy physical activity with maternal and neonatal health in white British and Pakistani-origin women from a deprived urban setting.

METHODS

The study was performed in 6921 pregnant women (53% Pakistani-origin) who contributed data for 7305 singleton births. At 26-28 weeks gestation, women were grouped into four activity levels (inactive/somewhat active/moderately active/active) based on their self-reported physical activity. Linear regression with robust standard errors was used to calculate adjusted mean differences in health markers between the four groups of physical activity (reference group: inactive).

RESULTS

Three-quarters (74%) of Pakistani-origin women and 39% of white British women were inactive. Trend-tests revealed that more active white British women tended to be less adipose, had lower fasting and postload glucose levels, lower triglyceride concentrations, and their babies were less adipose (smaller triceps and subscapular skinfolds) than less active white British women. Somewhat active Pakistani-origin women exhibited lower triglyceride concentrations and systolic blood pressure, higher high-density lipoprotein cholesterol levels, and their babies were less adipose (smaller mid-upper arm and abdominal circumferences; lower cord-blood leptin concentration) compared to inactive Pakistani-origin women. No associations were observed for gestational age or birth weight.

CONCLUSIONS

Physical activity performed mid-pregnancy was beneficially associated with maternal cardiometabolic health and neonatal adiposity, without influencing gestational age or birth weight. Associations were dose-dependent in white British women, and even a small amount of mid-pregnancy physical activity appeared to benefit some health markers in Pakistani-origin women.

Factors Associated with the Leisure-Time Physical Activity (LTPA) during the First Trimester of the Pregnancy: The Cross-Sectional Study among Pregnant Women in Serbia

Background: The benefits of physical activity during pregnancy include lower maternal weight gain, a lower likelihood of gestational diabetes, low back pain, preeclampsia, preterm delivery, caesarian delivery, and macrosomia. This study aimed to examine the factors associated with insufficient leisure-time physical activity (LTPA) during the first trimester. Methods: A cross-sectional study was conducted at the Clinic for Obstetrics and Gynecology of Clinical Center of Serbia, Belgrade, between January and June of 2018. The final analyses included 162/175 pregnant women. The questionnaire was used to obtain social characteristics, pregnancy, and lifestyle characteristics (Pregnancy Risk Assessment Monitoring System-PRAMS), pre-pregnancy LTPA (International Physical Activity Questionnaire-IPAQ), and LTPA during the first trimester (Pregnancy Physical Activity Questionnaire-PPAQ). Women were classified into two groups of sufficient and insufficient LTPA during the first trimester based on the recommendations of the World Health Organization. Multivariate logistic regression analysis was applied. Results: A total of 27.2% of the women had insufficient LTPA during pregnancy. Insufficient LTPA during pregnancy was associated with <12 years of education (OR: 2.3, 95% CI: 1.05-5.04), self-rated financial status as poor (OR: 0.34, 95% CI: 0.14-0.79), and hours spent walking before pregnancy (OR: 0.87, 95% CI: 0.77-0.99). Conclusions: Our results can help direct health care professionals advice for women who are planning pregnancy towards walking as it seems to be sustained during pregnancy.

Review of Recent Physical Activity Guidelines During Pregnancy to Facilitate Advice by Health Care Providers

Importance

Physical activity during pregnancy can offer many maternal and fetal health benefits.

Objective

The aim was to summarize American, Canadian, and international recommendations published recently on physical activity during pregnancy to aid health care providers in their delivery of advice on the topic.

Evidence Acquisition

A descriptive review of 3 national guidelines and 1 international guideline on physical activity during pregnancy was conducted. The guidelines included the 2019 Canadian recommendations, the 2018 United States' Physical Activity Guidelines for Americans (second edition), the 2015 (reaffirmed in 2017) American College of Obstetrics and Gynecology guideline, and the 2016-2018 International Olympic Committee recommendations for recreational and elite athletes.

Results

For apparently healthy women, under the guidance of their health care provider, moderate-intensity physical activity using both aerobic and muscle conditioning activities is recommended. The guidelines recommended at least 150 min/wk spread throughout the week (Canada, United States) or at least 20 to 30 min/d (American College of Obstetrics and Gynecology).

Conclusions and Relevance

This summary of 4 recent guidelines can facilitate use of updated recommendations by health care providers regarding physical activity during pregnancy. More detailed evidence-based guidelines on physical activity during postpartum are needed.

Gestational Exercise and Maternal and Child Health: Effects until Delivery and at Post-Natal Follow-up

We studied the influence of pregnancy exercise on maternal/offspring cardiometabolic health until delivery and at follow-up. We pooled data from two randomized controlled trials from our group that were performed following the same methodology (one unpublished). We also collected follow-up data de novo from the participants of both trials and their offspring. In total, 1348 women with uncomplicated, singleton gestations were assigned to an intervention (n = 688, performing a supervised, moderate-intensity exercise program (three sessions/week)) or control group (n = 660). Maternal outcomes were excessive gestational weight gain (EGWG), gestational hypertension/diabetes and, at follow-up, return to pre-pregnancy weight within six months, hypertension, overweight/obesity, and other cardiometabolic conditions. Offspring outcomes were macrosomia and low-birthweight and, at follow-up, overweight/obesity, low-weight, and cardiometabolic conditions. Adherence to the intervention, which proved safe, was > 95%. Pregnancy exercise reduced the risk of EGWG, gestational hypertension, and diabetes (adjusted odds ratio (OR) and 95% confidence interval: 0.60 (0.46–0.79), 0.39 (0.23–0.67), and 0.48 (0.28–0.84)), and it was associated with a greater likelihood of returning to pre-pregnancy weight (2.37 (1.26–4.54)) and a lower risk of maternal cardiometabolic conditions (0.27 (0.08–0.95)) at the end of follow-up (median 6.1 years (interquartile range 1.8)). Pregnancy exercise also reduced the risk of macrosomia (0.36 (0.20–0.63)) and of childhood overweight/obesity during the first year (0.20 (0.06–0.63)). Our findings suggest that pregnancy exercise might protect maternal/offspring health.

Psychosocial Stress, Sedentary Behavior, and Physical Activity during Pregnancy among Canadian Women: Relationships in a Diverse Cohort and a Nationwide Sample

BACKGROUND

Past research shows that psychosocial stress and distress predict sedentary behavior and physical activity, but few studies focus on pregnant women. Our objective was to analyze relationships between psychosocial stress and distress with sedentary behavior and physical activity among pregnant women in Canada.

METHODS

We analyzed objectively-measured sedentary behavior and physical activity at 16-18, 24-26, and 32-24 weeks pregnancy in a sociodemographically diverse cohort of 70 women in Montreal, Canada. Participants completed the Perceived Stress Questionnaire and wore an accelerometer for 3 days that quantified sitting time and steps per day. We used univariate general linear models to analyze relationships between perceived stress with sedentary behavior and physical activity at each evaluation. To assess generalizability, we analyzed relationships between psychological distress with self-reported leisure-time sedentary behavior and daily energy expenditure in transportation and leisure physical activities among a sample representative of 166,095 women in the Canadian Community Health Survey.

RESULTS

In the Montreal cohort, we observed a positive association between perceived stress and sitting time, with small to moderate effect sizes (partial η2 = 0.08-0.16). We observed negative relationships between perceived stress and steps per day at the first two evaluations only, with small to moderate effect sizes (partial η2 = 0.08-0.11). Relationships for sedentary behavior were similar in the nationwide sample, but with smaller effect sizes (partial η2 = 0.02). There were no relationships between distress and physical activity in the nationwide sample.

CONCLUSION

Psychosocial stress represents one risk factor for sedentarity, with relationships evident throughout pregnancy and at the population level. Relationships with physical activity are less consistent, but stress might represent a risk factor for low physical activity in early to mid-pregnancy. Results might guide the development of more comprehensive interventions targeting stress, sedentarity, and physical activity. In particular, integrating psychosocial health into interventions to reduce sedentarity, and including concrete guidelines on sedentary behavior in psychosocial health interventions, might be prioritized.

High maternal self-efficacy is associated with meeting Institute of Medicine gestational weight gain recommendations

Objective

Fetal exposure to an intrauterine environment affected by maternal obesity and excessive gestational weight gain increases the likelihood of infants born large for gestational age and childhood obesity. This study examined behavioural factors and lifestyle practices associated with women’s perceived attainability of meeting the 2009 Institute of Medicine (IOM) weight gain guidelines.

Methods

Cross-sectional data were collected from pregnant (n = 320) and postpartum (n = 1179) women who responded to the validated Canadian Electronic Maternal (EMat) health survey. Consenting women completed the survey through REDCap^™ a secure, web-based data capture platform. Multiple logistic regression analyses were used to evaluate correlates associated with meeting or not meeting IOM recommendations. Odds ratios (ORs) were adjusted for relevant behavioural and sociodemographic covariates.

Results

There were no significant differences between adjusted and unadjusted ORs for self-efficacy, barriers, and facilitators to weight gain during pregnancy. Women who reported worry regarding weight gain were significantly less likely to meet IOM guidelines (OR = 0.48, 95% CI = 0.33–0.69). Perceived controllability of behaviour was significantly associated with meeting IOM guidelines. An internal locus of control for weight gain was associated with an increased odds of meeting guidelines when women perceived to be in control of their weight gain (OR = 1.75, 95% CI = 1.29–2.37), healthy and exercised (OR = 1.91, 95% CI = 1.34–2.71), and when no barriers to healthy weight gain were perceived (OR = 1.43, 95% CI = 1.04–1.95); whereas, an external locus of control in which women viewed weight gain as beyond their control, was associated with a significantly reduced odds of achieving guidelines (OR = 0.58, 95% CI = 0.39–0.88).

Conclusions

Self-efficacy and perceived controllability of behaviour are key factors to consider when developing pregnancy-specific interventions to help women achieve guideline-concordant weight gain and ensure the downstream health of both mother and infant.

Influence of a Concurrent Exercise Training Intervention during Pregnancy on Maternal and Arterial and Venous Cord Serum Cytokines: The GESTAFIT Project

The aim of the present study was to analyze the influence of a supervised concurrent exercise-training program, from the 17th gestational week until delivery, on cytokines in maternal (at 17th and 35th gestational week, and at delivery) and arterial and venous cord serum. Fifty-eight Caucasian pregnant women (age: 33.5 ± 4.7 years old, body mass index: 23.6 ± 4.1kg/m²) from the GESTAFIT Project (exercise (n = 37) and control (n = 21) groups) participated in this quasi-experimental study (per-protocol basis). The exercise group followed a 60-min 3 days/week concurrent (aerobic-resistance) exercise-training from the 17th gestational week to delivery. Maternal and arterial and venous cord serum cytokines (fractalkine, interleukin (IL)-1β, IL-6, IL-8, IL-10, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α) were assessed using Luminex xMAP technology. In maternal serum (after adjusting for the baseline values of cytokines), the exercise group decreased TNF-α (from baseline to 35th week, p = 0.02), and increased less IL-1β (from baseline to delivery, p = 0.03) concentrations than controls. When adjusting for other potential confounders, these differences became non-significant. In cord blood, the exercise group showed reduced arterial IL-6 and venous TNF-α (p = 0.03 and p = 0.001, respectively) and higher concentrations of arterial IL-1β (p = 0.03) compared to controls. The application of concurrent exercise-training programs could be a strategy to modulate immune responses in pregnant women and their fetuses. However, future research is needed to better understand the origin and clearance of these cytokines, their role in the maternal-placental-fetus crosstalk, and the influence of exercise interventions on them.

Experiences regarding nutrition and exercise among women during early postpartum: a qualitative grounded theory study

BACKGROUND

Excess gestational weight gain has long- and short-term implications for women and children, and postpartum weight retention is associated with an increased risk of long-term obesity. Despite the existence of dietary and exercise guidelines, many women struggle to return to pre-pregnancy weight. Experiences of women in tackling postpartum weight loss are poorly understood. We undertook this study to explore experiences related to nutrition, exercise and weight in the postpartum in women in Ontario, Canada.

METHODS

This was a nested qualitative study within The Be Healthy in Pregnancy Study, a randomized controlled trial. Women randomized to the control group were invited to participate. Semi-structured focus groups were conducted at 4-6 months postpartum. Focus groups were audio recorded, transcribed verbatim, coded and analyzed thematically using a constructivist grounded theory approach.

RESULTS

Women experienced a complex relationship with their body image, due to unrealistic expectations related to their postpartum body. Participants identified barriers and enablers to healthy habits during pregnancy and postpartum. Gestational weight gain guidelines were regarded as unhelpful and unrealistic. A lack of guidance and information about weight management, healthy eating, and exercise in the postpartum period was highlighted.

CONCLUSION

Strategies for weight management that target the unique characteristics of the postpartum period have been neglected in research and in patient counselling. Postpartum women may begin preparing for their next pregnancy and support during this period could improve their health for subsequent pregnancies.

TRIAL REGISTRATION

NCT01689961 registered September 21, 2012.

Greater energy demand of exercise during pregnancy does not impact mechanical efficiency

Pregnant women are recommended to engage in 150 min of moderate-intensity physical activity per week to reduce pregnancy complications. Many women struggle to remain physically active throughout pregnancy, and there is no consensus about whether women adopt a less efficient movement pattern as they progress through pregnancy and experience gestational weight gain. This study assessed the change in energy expenditure and mechanical efficiency in pregnant women (PREG; n = 10) when performing a walking treadmill task in early, mid, and late pregnancy and also compared with an age- and body mass index-matched, nonpregnant (CON; n = 10) group. On average, the PREG group gained within the Institute of Medicine's gestational weight gain guidelines (11.6 ± 3.6 kg) and were all inactive (measured using accelerometry), except for 1 participant, by the third trimester, as per the 2019 Canadian physical activity guidelines for pregnant women. Energy expended to complete the walking task increased throughout pregnancy and was higher than the controls (111.5 ± 24.6 kcal) in mid and late pregnancy (139.0 ± 22.2 kcal, p = 0.02, and 147.3 ± 24.6 kcal, p = 0.005, respectively), but not early pregnancy (129.9 ± 18.9 kcal, p = 0.08). Walking mechanical efficiency was similar within pregnant women at each time point and compared to nonpregnant controls. Our findings add to the growing body of evidence demonstrating that pregnant women can safely perform physical activity by showing that walking mechanical efficiency is unchanged at low to moderate intensities. Novelty Energy demand during exercise increases proportionally to weight gain across pregnancy trimesters. However, mechanical efficiency remains unchanged during low- to moderate-intensity walking.

Examination of the Myokine Response in Pregnant and Non-pregnant Women Following an Acute Bout of Moderate-Intensity Walking

Background

It is recommended that women accumulate 150-min of weekly moderate-intensity physical activity (MPA) when pregnant. Engaging in regular physical activity (PA) confers many health benefits to both the mother and the fetus. However, the molecular mechanisms by which these health benefits are bestowed are not well understood. One potential factor that may be contributing to the observed benefits is myokines, which are small peptides secreted by skeletal muscles. In the non-pregnant population, myokines are believed to be involved in the molecular mechanisms resulting from PA. The objective of this study was to characterize and compare the myokine profile of pregnant and non-pregnant women, after an acute bout of MPA.

Methods

Pregnant (n = 13) and non-pregnant (n = 17) women were recruited from the Ottawa region to undergo a treadmill walking session at moderate-intensity (40–60% heart rate reserve). Pre- and post-exercise serum samples were taken, and a set of 15 myokines were analyzed although only 10 were detected. IL-6 was analyzed using a high-sensitivity assay, while FGF21, EPO, BDNF, Fractalkine, IL-15, SPARC, FABP-3, FSTL-1, and oncostatin were analyzed using various multiplex assays.

Results

The pregnant and non-pregnant groups did not differ in terms of age, height, non/pre-pregnancy weight, BMI, and resting heart rate. Baseline levels of EPO and oncostatin were higher in the pregnant group while FGF21 was higher in the non-pregnant group. Circulating levels of three myokines, FGF21, EPO, and IL-15 significantly increased in response to the acute exercise in the pregnant group. Non-pregnant women exhibited an increase in three myokines, FABP-3, FSTL-1, and oncostatin, while one myokine, EPO, decreased post-exercise. SPARC, fractalkine and BDNF were shown to increase post-exercise regardless of pregnancy status while the response for BDNF was more pronounced in the non-pregnant group.

Conclusion

This is the first study examining myokine response following an acute bout of PA in pregnancy. Moderate intensity PA, which is recommended during pregnancy, elicited an increase in four myokines post-compared to pre-exercise in the pregnant group. Further research is warranted to understand the role of myokines in pregnancy.

The Avoiding Diabetes After Pregnancy Trial in Moms Program: Feasibility of a Diabetes Prevention Program for Women With Recent Gestational Diabetes Mellitus

OBJECTIVE

Our aim in this study was to evaluate the feasibility of a home-based diabetes prevention program, delivered by interdisciplinary certified diabetes educators (CDEs), and customized for postpartum women with recent gestational diabetes mellitus (GDM).

METHODS

This pilot randomized trial recruited women with GDM from 24 to 40 weeks gestation from 4 centres, and trained 10 CDEs in behaviour coaching, physical activity (PA) and low glycemic index education. Women were randomized after 3 months postpartum to standard care (1 visit) or 1 of 3 24-week coaching interventions (1 visit and 12 telephone calls): i) PA and diet, ii) PA only or iii) diet only. Feasibility outcomes included recruitment, retention, adherence and satisfaction.

RESULTS

Of 1,342 eligible patients, 392 were actively invited (29.3%) and 227 (16.9%) consented. Of these, 149 (65.6%) were randomized postpartum, of whom 131 (87.9%) started the program and 105 (70.5%) attended the final assessment. Intervention arm participants completed a median 75% (interquartile range, 50% to 92%) of telephone calls. Visit and call duration were a mean 71.4 (standard deviation, 13.8) and 18.1 (standard deviation, 6.5) minutes, respectively. Participants reported excellent/very good satisfaction 73% of the time, and 87% would recommend the program to others.

CONCLUSIONS

A home-based diabetes prevention program customized for postpartum women with GDM can be feasibly delivered by CDEs, and it is associated with >70% retention, adherence and satisfaction.

The effects of vigorous intensity exercise in the third trimester of pregnancy: a systematic review and meta-analysis

Background

Fetal growth is dependent upon utero-placental vascular supply of oxygen and nutrients from the mother and has been proposed to be compromised by vigorous intensity exercise in the third trimester. The aim of this systematic review was to investigate the effects of vigorous intensity exercise performed throughout pregnancy, on infant and maternal outcomes.

Methods

Electronic searching of the PubMed, Medline, EMBASE, Cochrane Library, Web of Science and CINAHL databases was used to conduct the search up to November 2018. Study designs included in the systematic review were randomised control trials, quasi-experimental studies, cohort studies and case-control studies. The studies were required to include an intervention or report of pregnant women performing vigorous exercise during gestation, with a comparator group of either lower intensity exercise or standard care.

Results

Ten cohort studies (n = 32,080) and five randomized control trials (n = 623) were included in the systematic review (n = 15), with 13 studies included in the meta-analysis. No significant difference existed in birthweight for infants of mothers who engaged in vigorous physical activity and those who lacked this exposure (mean difference = 8.06 g, n = 8006). Moreover, no significant increase existed in risk of small for gestational age (risk ratio = 0.15, n = 4504), risk of low birth weight (< 2500 g) (risk ratio = 0.44, n = 2454) or maternal weight gain (mean difference = − 0.46 kg, n = 1834). Women who engaged in vigorous physical activity had a small but significant increase in length of gestational age before delivery (mean difference = 0.21 weeks, n = 4281) and a small but significantly reduced risk of prematurity (risk ratio = − 0.20, n = 3025).

Conclusions

Findings from this meta-analysis indicate that vigorous intensity exercise completed into the third trimester appears to be safe for most healthy pregnancies. Further research is needed on the effects of vigorous intensity exercise in the first and second trimester, and of exercise intensity exceeding 90% of maximum heart rate.

Trial registration

PROSPERO trial registration CRD42018102109.

Electronic supplementary material

The online version of this article (10.1186/s12884-019-2441-1) contains supplementary material, which is available to authorized users.

Exercise in Pregnant Women with Diabetes

PURPOSE OF REVIEW

Diabetes affects an increasing number of pregnancies. Regular exercise is recommended for pregnant women without diabetes, but whether exercise during pregnancy also benefits women with gestational diabetes (GDM) or preexisting (type 1 or type 2) diabetes or if these women have any specific risks is unclear.

RECENT FINDINGS

Recent evidence suggests that low- to moderate-intensity exercise improves blood glucose and may delay insulin initiation for women with GDM. Exercise is also safe, with no reports of increased maternal or neonatal complications. Few studies evaluated exercise as adjunct therapy for pregnant women with preexisting diabetes, precluding a thorough assessment in this population. Low- to moderate-intensity exercise during pregnancy safely improves glycemic control among women with GDM. More studies are needed to evaluate the impact of exercise in pregnant women with preexisting diabetes. Whether a specific type, volume, or timing of activity is most effective is not known.

Energy Intake Requirements in Pregnancy

Energy intake requirements in pregnancy match the demands of resting metabolism, physical activity, and tissue growth. Energy balance in pregnancy is, therefore, defined as energy intake equal to energy expenditure plus energy storage. A detailed understanding of these components and their changes throughout gestation can inform energy intake recommendations for minimizing the risk of poor pregnancy outcomes. Energy expenditure is the sum of resting and physical activity-related expenditure. Resting metabolic rate increases during pregnancy as a result of increased body mass, pregnancy-associated physiological changes, i.e., cardiac output, and the growing fetus. Physical activity is extremely variable between women and may change over the course of pregnancy. The requirement for energy storage depends on maternal pregravid body size. For optimal pregnancy outcomes, women with low body weight require more fat mass accumulation than women with obesity, who do not require to accumulate fat mass at all. Given the high energy density of fat mass, these differences affect energy intake requirements for a healthy pregnancy greatly. In contrast, the energy stored in fetal and placental tissues is comparable between all women and have small impact on energy requirements. Different prediction equations have been developed to quantify energy intake requirements and we provide a brief review of the strengths and weaknesses and discuss their application for healthy management of weight gain in pregnant women.

Physical Activity and Depressive Disorders in Pregnant Women-A Systematic Review

Background and Objectives: Pregnancy is a unique period in the life of every woman. The lifestyle of a pregnant woman has a significant impact on her and her child's health. Regular physical activity is one of the elements that help maintain normal mental and physical well-being. In pregnant women who regularly have moderate physical activity, there is a lower risk of developing obesity and overweight. Physical exercises have an impact on maintaining proper muscular tonus, reduce pain and prepare for the exertion during labour. Based on the available literature, the aim of this study was to present the impact of physical activity on depressive disorders in pregnant women. Materials and Methods: A review of the literature was carried out in the Medline PubMed database. The basic search terms were: "pregnancy" AND "physical activity AND depression". The work included only English-language publications published in the years 2000-2018. Results: A total of 408 references were found. On the basis of an analysis of titles, abstracts and the language of publication (other than English), 354 articles were rejected, and 54 articles were fully read, of which five were rejected due to lack of access to the full version. Finally, 17 references were included in the review. Conclusions: Physical activity, at least once a week, significantly reduces the symptoms of depression in pregnant women and may be an important factor in the prevention of depression in this period.

Can Off-Training Physical Behaviors Influence Recovery in Athletes? A Scoping Review

Recently, the attention on recovery in sport increased enormously although there is lack of scientific evidence on the role of lifestyle in terms of movement [i.e., physical behaviors (PBs)], apart from sleep. Few studies assessed physical activity (PA) and sedentary behavior (SB) in athletes. The aims of this scoping review were to answer to the following scientific questions: (1) How active/inactive are competitive athletes out of training? (2) Do off-training PBs affect recovery, performance, and health? (3) What strategies can be implemented to improve recovery using off-training PBs, apart from sleep? From 1,116 potentially relevant articles, nine were eligible for inclusion in this review. The main issues identified were related to the heterogeneity concerning the types of sports, age category, gender, competitive level, sample size, and instruments/devices adopted, the paucity of studies investigating the effects of PBs while awake on recovery, and the lack of experimental designs manipulating PBs while awake to accelerate recovery. Furthermore, PA and SB domains were rarely investigated, while no research articles focused on the combined effect of 24-h PBs. Eight out of nine studies measured PA, seven SB, and two included sleep. Three studies included training practice into PA measurement by the means of accelerometry. Overall, almost the totality of the athletes achieved recommended PA levels although they sustained prolonged SB. In conclusion, more descriptive researches are needed in different athletic populations and settings. Furthermore, experimental designs aimed at investigating the effects of PBs manipulation on recovery and the putative mechanisms are encouraged.

Domain-specific physical activity and sedentary behavior during pregnancy and postpartum depression risk in the French EDEN and ELFE cohorts

The potential beneficial effects of physical activity during pregnancy on postpartum depressive symptoms (PPD) remain inconclusive. Using data from two prospective French birth cohorts, we aimed to examine the relationship between domain-specific physical activity (including leisure-time sedentary behavior) in pregnancy and the occurrence of PPD. Participants of the ELFE cohort (n = 15,538) completed the Pregnancy Physical Activity Questionnaire (PPAQ), which assesses the following physical activity/sedentary behavior domains: household/caregiving, occupational, sports/exercise, transportation and leisure-time sedentary behavior during the third pregnancy trimester. In the EDEN cohort (n = 1745) women completed the Baecke Questionnaire (BQ) measuring occupational, sports/exercise, and leisure-time activity during the first trimester of pregnancy. Depressive symptoms in the first postpartum year were measured using the Edinburgh Postnatal Depression Scale in both cohorts. Associations of physical activity/sedentary behavior with PPD symptoms were determined by logistic regression analysis, with adjustment on potential confounding factors. In the adjusted models, higher levels of household/caregiving activities (OR = 1.10 (95% CI 1.01-1.19)) and leisure-time sedentary behavior (OR = 1.16 (95% CI 1.06-1.23)), in the third pregnancy trimester were associated with an increased odds of PPD. No significant associations were found for physical activity domains during the first pregnancy trimester. Higher levels of household and caregiving activities and leisure-time sedentary behavior in the last trimester of pregnancy appear to increase the likelihood of postpartum depression. Purpose and context should be taken into account when encouraging physical activity as a strategy to help prevent postpartum mental health problems from pregnancy onwards. Reducing sedentary behavior could be a complementary strategy.

Prenatal exercise (including but not limited to pelvic floor muscle training) and urinary incontinence during and following pregnancy: a systematic review and meta-analysis

OBJECTIVE

To examine the relationships between prenatal physical activity and prenatal and postnatal urinary incontinence (UI).

DESIGN

Systematic review with random effects meta-analysis and meta-regression.

DATA SOURCES

Online databases were searched up to 6 January 2017.

STUDY ELIGIBILITY CRITERIA

Studies of all designs were included (except case studies) if they were published in English, Spanish or French and contained information on the Population (pregnant women without contraindication to exercise), Intervention (subjective or objective measures of frequency, intensity, duration, volume or type of exercise, alone ["exercise-only"] or in combination with other intervention components [e.g., dietary; "exercise + co-intervention"]), Comparator (no exercise or different frequency, intensity, duration, volume and type of exercise) and Outcome (prenatal or postnatal UI).

RESULTS

24 studies (n=15 982 women) were included. 'Low' to 'moderate' quality evidence revealed prenatal pelvic floor muscle training (PFMT) with or without aerobic exercise decreased the odds of UI in pregnancy (15 randomised controlled trials (RCTs), n=2764 women; OR 0.50, 95% CI 0.37 to 0.68, I²=60%) and in the postpartum period (10 RCTs, n=1682 women; OR 0.63, 95% CI 0.51, 0.79, I²=0%). When we analysed the data by whether women were continent or incontinent prior to the intervention, exercise was beneficial at preventing the development of UI in women with continence, but not effective in treating UI in women with incontinence. There was 'low' quality evidence that prenatal exercise had a moderate effect in the reduction of UI symptom severity during (five RCTs, standard mean difference (SMD) -0.54, 95% CI -0.88 to -0.20, I²=64%) and following pregnancy (three RCTs, 'moderate' quality evidence; SMD -0.54, 95% CI -0.87 to -0.22, I²=24%).

CONCLUSION

Prenatal exercise including PFMT reduced the odds and symptom severity of prenatal and postnatal UI. This was the case for women who were continent before the intervention. Among women who were incontinent during pregnancy, exercise training was not therapeutic.

Effects of prenatal exercise on incidence of congenital anomalies and hyperthermia: a systematic review and meta-analysis

OBJECTIVE

To investigate the relationships between exercise and incidence of congenital anomalies and hyperthermia.

DESIGN

Systematic review with random-effects meta-analysis .

DATA SOURCES

Online databases were searched from inception up to 6 January 2017.

STUDY ELIGIBILITY CRITERIA

Studies of all designs were eligible (except case studies and reviews) if they were published in English, Spanish or French, and contained information on population (pregnant women without contraindication to exercise), intervention (subjective or objective measures of frequency, intensity, duration, volume or type of exercise, alone ["exercise-only"] or in combination with other intervention components [e.g., dietary; "exercise + co-intervention"]), comparator (no exercise or different frequency, intensity, duration, volume or type of exercise) and outcome (maternal temperature and fetal anomalies).

RESULTS

This systematic review and meta-analysis included 'very low' quality evidence from 14 studies (n=78 735) reporting on prenatal exercise and the odds of congenital anomalies, and 'very low' to 'low' quality evidence from 15 studies (n=447) reporting on maternal temperature response to prenatal exercise. Prenatal exercise did not increase the odds of congenital anomalies (OR 1.23, 95% CI 0.77 to 1.95, I²=0%). A small but significant increase in maternal temperature was observed from pre-exercise to both during and immediately after exercise (during: 0.26°C, 95% CI 0.12 to 0.40, I²=70%; following: 0.24°C, 95% CI 0.17 to 0.31, I²=47%).

SUMMARY/CONCLUSIONS

These data suggest that moderate-to-vigorous prenatal exercise does not induce hyperthermia or increase the odds of congenital anomalies. However, exercise responses were investigated in most studies after 12 weeks' gestation when the risk of de novo congenital anomalies is negligible.

Exercise for the prevention and treatment of low back, pelvic girdle and lumbopelvic pain during pregnancy: a systematic review and meta-analysis

Objective

The purpose of this review was to investigate the relationship between prenatal exercise, and low back (LBP), pelvic girdle (PGP) and lumbopelvic (LBPP) pain.

Design

Systematic review with random effects meta-analysis and meta-regression.

Data sources

Online databases were searched up to 6 January 2017.

Study eligibility criteria

Studies of all designs were eligible (except case studies and reviews) if they were published in English, Spanish or French, and contained information on the population (pregnant women without contraindication to exercise), intervention (subjective or objective measures of frequency, intensity, duration, volume or type of exercise, alone [“exercise-only”] or in combination with other intervention components [eg, dietary; “exercise + co-intervention”]), comparator (no exercise or different frequency, intensity, duration, volume and type of exercise) and outcome (prevalence and symptom severity of LBP, PGP and LBPP).

Results

The analyses included data from 32 studies (n=52 297 pregnant women). ‘Very low’ to ‘moderate’ quality evidence from 13 randomised controlled trials (RCTs) showed prenatal exercise did not reduce the odds of suffering from LBP, PGP and LBPP either in pregnancy or the postpartum period. However, ‘very low’ to ‘moderate’ quality evidence from 15 RCTs identified lower pain severity during pregnancy and the early postpartum period in women who exercised during pregnancy (standardised mean difference −1.03, 95% CI −1.58, –0.48) compared with those who did not exercise. These findings were supported by ‘very low’ quality evidence from other study designs.

Conclusion

Compared with not exercising, prenatal exercise decreased the severity of LBP, PGP or LBPP during and following pregnancy but did not decrease the odds of any of these conditions at any time point.

Impact of prenatal exercise on maternal harms, labour and delivery outcomes: a systematic review and meta-analysis

OBJECTIVE

To perform a systematic review of the relationships between prenatal exercise and maternal harms including labour/delivery outcomes.

DESIGN

Systematic review with random effects meta-analysis and meta-regression.

DATASOURCES

Online databases were searched up to 6 January 2017.

STUDY ELIGIBILITY CRITERIA

Studies of all designs were included (except case studies) if they were published in English, Spanish or French and contained information on the population (pregnant women without contraindication to exercise), intervention (subjective or objective measures of frequency, intensity, duration, volume or type of exercise), comparator (no exercise or different frequency, intensity, duration, volume and type of exercise, alone ["exercise-only"] or in combination with other intervention components [e.g., dietary; "exercise + co-intervention"]) and outcome (preterm/prelabour rupture of membranes, caesarean section, instrumental delivery, induction of labour, length of labour, vaginal tears, fatigue, injury, musculoskeletal trauma, maternal harms (author defined) and diastasis recti).

RESULTS

113 studies (n=52 858 women) were included. 'Moderate' quality evidence from exercise-only randomised controlled trials (RCTs) indicated a 24% reduction in the odds of instrumental delivery in women who exercised compared with women who did not (20 RCTs, n=3819; OR 0.76, 95% CI 0.63 to 0.92, I ²= 0 %). The remaining outcomes were not associated with exercise. Results from meta-regression did not identify a dose-response relationship between frequency, intensity, duration or volume of exercise and labour and delivery outcomes.

SUMMARY/CONCLUSIONS

Prenatal exercise reduced the odds of instrumental delivery in the general obstetrical population. There was no relationship between prenatal exercise and preterm/prelabour rupture of membranes, caesarean section, induction of labour, length of labour, vaginal tears, fatigue, injury, musculoskeletal trauma, maternal harms and diastasis recti.

Impact of prenatal exercise on both prenatal and postnatal anxiety and depressive symptoms: a systematic review and meta-analysis

Objective

To examine the influence of prenatal exercise on depression and anxiety during pregnancy and the postpartum period.

Design

Systematic review with random effects meta-analysis and meta-regression.

Data sources

Online databases were searched up to 6 January 2017.

Study eligibility criteria

Studies of all designs were included (except case studies) if they were published in English, Spanish or French and contained information on the Population (pregnant women without contraindication to exercise), Intervention (subjective or objective measures of frequency, intensity, duration, volume or type of exercise), Comparator (no exercise or different frequency, intensity, duration, volume and type of exercise) and Outcome (prenatal or postnatal depression or anxiety).

Results

A total of 52 studies (n=131 406) were included. ‘Moderate’ quality evidence from randomised controlled trials (RCTs) revealed that exercise-only interventions, but not exercise+cointerventions, reduced the severity of prenatal depressive symptoms (13 RCTs, n=1076; standardised mean difference: −0.38, 95% CI −0.51 to –0.25, I2=10%) and the odds of prenatal depression by 67% (5 RCTs, n=683; OR: 0.33, 95% CI 0.21 to 0.53, I2=0%) compared with no exercise. Prenatal exercise did not alter the odds of postpartum depression or the severity of depressive symptoms, nor anxiety or anxiety symptoms during or following pregnancy. To achieve at least a moderate effect size in the reduction of the severity of prenatal depressive symptoms, pregnant women needed to accumulate at least 644 MET-min/week of exercise (eg, 150 min of moderate intensity exercise, such as brisk walking, water aerobics, stationary cycling, resistance training).

Summary/Conclusions

Prenatal exercise reduced the odds and severity of prenatal depression.

Impact of prenatal exercise on neonatal and childhood outcomes: a systematic review and meta-analysis

Objective

We aimed to identify the relationship between maternal prenatal exercise and birth complications, and neonatal and childhood morphometric, metabolic and developmental outcomes.

Design

Systematic review with random-effects meta-analysis and meta-regression.

Data sources

Online databases were searched up to 6 January 2017.

Study eligibility criteria

Studies of all designs were eligible (except case studies and reviews) if published in English, Spanish or French, and contained information on the relevant population (pregnant women without contraindication to exercise), intervention (subjective/objective measures of frequency, intensity, duration, volume or type of exercise, alone (‘exercise-only’) or in combination with other intervention components (eg, dietary; ‘exercise+cointervention’)), comparator (no exercise or different frequency, intensity, duration, volume, type or trimester of exercise) and outcomes (preterm birth, gestational age at delivery, birth weight, low birth weight (<2500 g), high birth weight (>4000 g), small for gestational age, large for gestational age, intrauterine growth restriction, neonatal hypoglycaemia, metabolic acidosis (cord blood pH, base excess), hyperbilirubinaemia, Apgar scores, neonatal intensive care unit admittance, shoulder dystocia, brachial plexus injury, neonatal body composition (per cent body fat, body weight, body mass index (BMI), ponderal index), childhood obesity (per cent body fat, body weight, BMI) and developmental milestones (including cognitive, psychosocial, motor skills)).

Results

A total of 135 studies (n=166 094) were included. There was ‘high’ quality evidence from exercise-only randomised controlled trials (RCTs) showing a 39% reduction in the odds of having a baby >4000 g (macrosomia: 15 RCTs, n=3670; OR 0.61, 95% CI 0.41 to 0.92) in women who exercised compared with women who did not exercise, without affecting the odds of growth-restricted, preterm or low birth weight babies. Prenatal exercise was not associated with the other neonatal or infant outcomes that were examined.

Conclusions

Prenatal exercise is safe and beneficial for the fetus. Maternal exercise was associated with reduced odds of macrosomia (abnormally large babies) and was not associated with neonatal complications or adverse childhood outcomes.

Prenatal exercise for the prevention of gestational diabetes mellitus and hypertensive disorders of pregnancy: a systematic review and meta-analysis

Objective

Gestational diabetes mellitus (GDM), gestational hypertension (GH) and pre-eclampsia (PE) are associated with short and long-term health issues for mother and child; prevention of these complications is critically important. This study aimed to perform a systematic review and meta-analysis of the relationships between prenatal exercise and GDM, GH and PE.

Design

Systematic review with random effects meta-analysis and meta-regression.

Data sources

Online databases were searched up to 6 January 2017.

Study eligibility criteria

Studies of all designs were included (except case studies) if published in English, Spanish or French, and contained information on the Population (pregnant women without contraindication to exercise), Intervention (subjective or objective measures of frequency, intensity, duration, volume or type of exercise, alone [“exercise-only”] or in combination with other intervention components [e.g., dietary; “exercise + co-intervention”]), Comparator (no exercise or different frequency, intensity, duration, volume and type of exercise) and Outcomes (GDM, GH, PE).

Results

A total of 106 studies (n=273 182) were included. ‘Moderate’ to ‘high’-quality evidence from randomised controlled trials revealed that exercise-only interventions, but not exercise+cointerventions, reduced odds of GDM (n=6934; OR 0.62, 95% CI 0.52 to 0.75), GH (n=5316; OR 0.61, 95% CI 0.43 to 0.85) and PE (n=3322; OR 0.59, 95% CI 0.37 to 0.9) compared with no exercise. To achieve at least a 25% reduction in the odds of developing GDM, PE and GH, pregnant women need to accumulate at least 600 MET-min/week of moderate-intensity exercise (eg, 140 min of brisk walking, water aerobics, stationary cycling or resistance training).

Summary/conclusions

In conclusion, exercise-only interventions were effective at lowering the odds of developing GDM, GH and PE.

Prenatal exercise is not associated with fetal mortality: a systematic review and meta-analysis

OBJECTIVE

To perform a systematic review of the relationship between prenatal exercise and fetal or newborn death.

DESIGN

Systematic review with random-effects meta-analysis and meta-regression.

DATA SOURCES

Online databases were searched up to 6 January 2017.

STUDY ELIGIBILITY CRITERIA

Studies of all designs were included (except case studies) if they were published in English, Spanish or French and contained information on the population (pregnant women without contraindication to exercise), intervention (subjective or objective measures of frequency, intensity, duration, volume or type of exercise, alone ["exercise-only"] or in combination with other intervention components [eg, dietary; "exercise + co-intervention"]), comparator (no exercise or different frequency, intensity, duration, volume and type of exercise) and outcome (miscarriage or perinatal mortality).

RESULTS

Forty-six studies (n=2 66 778) were included. There was 'very low' quality evidence suggesting no increased odds of miscarriage (23 studies, n=7125 women; OR 0.88, 95% CI 0.63 to 1.21, I²=0%) or perinatal mortality (13 studies, n=6837 women, OR 0.86, 95% CI 0.49 to 1.52, I²=0%) in pregnant women who exercised compared with those who did not. Stratification by subgroups did not affect odds of miscarriage or perinatal mortality. The meta-regressions identified no associations between volume, intensity or frequency of exercise and fetal or newborn death. As the majority of included studies examined the impact of moderate intensity exercise to a maximum duration of 60 min, we cannot comment on the effect of longer periods of exercise.

SUMMARY/CONCLUSIONS

Although the evidence in this field is of 'very low' quality, it suggests that prenatal exercise is not associated with increased odds of miscarriage or perinatal mortality. In plain terms, this suggests that generally speaking exercise is 'safe' with respect to miscarriage and perinatal mortality.

Effectiveness of exercise interventions in the prevention of excessive gestational weight gain and postpartum weight retention: a systematic review and meta-analysis

Objective

Gestational weight gain (GWG) has been identified as a critical modifier of maternal and fetal health. This systematic review and meta-analysis aimed to examine the relationship between prenatal exercise, GWG and postpartum weight retention (PPWR).

Design

Systematic review with random effects meta-analysis and meta-regression. Online databases were searched up to 6 January 2017.

Study eligibility criteria

Studies of all designs in English, Spanish or French were eligible (except case studies and reviews) if they contained information on the population (pregnant women without contraindication to exercise), intervention (frequency, intensity, duration, volume or type of exercise, alone [“exercise-only”] or in combination with other intervention components [eg, dietary; “exercise + co-intervention”]), comparator (no exercise or different frequency, intensity, duration, volume or type of exercise) and outcomes (GWG, excessive GWG (EGWG), inadequate GWG (IGWG) or PPWR).

Results

Eighty-four unique studies (n=21 530) were included. ‘Low’ to ‘moderate’ quality evidence from randomised controlled trials (RCTs) showed that exercise-only interventions decreased total GWG (n=5819; −0.9 kg, 95% CI −1.23 to –0.57 kg, I2=52%) and PPWR (n=420; −0.92 kg, 95% CI −1.84 to 0.00 kg, I2=0%) and reduced the odds of EGWG (n=3519; OR 0.68, 95% CI 0.57 to 0.80, I2=12%) compared with no exercise. ‘High’ quality evidence indicated higher odds of IGWG with prenatal exercise-only (n=1628; OR 1.32, 95% CI 1.04 to 1.67, I2=0%) compared with no exercise.

Conclusions

Prenatal exercise reduced the odds of EGWG and PPWR but increased the risk of IGWG. However, the latter result should be interpreted with caution because it was based on a limited number of studies (five RCTs).

Glucose responses to acute and chronic exercise during pregnancy: a systematic review and meta-analysis

Objective

To perform a systematic review and meta-analysis to explore the relationship between prenatal exercise and glycaemic control.

Design

Systematic review with random-effects meta-analysis and meta-regression.

Data sources

Online databases were searched up to 6 January 2017.

Study eligibility criteria

Studies of all designs were included (except case studies and reviews) if they were published in English, Spanish or French, and contained information on the population (pregnant women without contraindication to exercise), intervention (subjective or objective measures of frequency, intensity, duration, volume or type of acute or chronic exercise, alone (‘exercise-only’) or in combination with other intervention components (eg, dietary; ‘exercise+cointervention’) at any stage of pregnancy), comparator (no exercise or different frequency, intensity, duration, volume and type of exercise) and outcome (glycaemic control).

Results

A total of 58 studies (n=8699) were included. There was ‘very low’ quality evidence showing that an acute bout of exercise was associated with a decrease in maternal blood glucose from before to during exercise (6 studies, n=123; mean difference (MD) −0.94 mmol/L, 95% CI −1.18 to −0.70, I2=41%) and following exercise (n=333; MD −0.57 mmol/L, 95% CI −0.72 to −0.41, I2=72%). Subgroup analysis showed that there were larger decreases in blood glucose following acute exercise in women with diabetes (n=26; MD −1.42, 95% CI −1.69 to −1.16, I2=8%) compared with those without diabetes (n=285; MD −0.46, 95% CI −0.60 to −0.32, I2=62%). Finally, chronic exercise-only interventions reduced fasting blood glucose compared with no exercise postintervention in women with diabetes (2 studies, n=70; MD −2.76, 95% CI −3.18 to −2.34, I2=52%; ‘low’ quality of evidence), but not in those without diabetes (9 studies, n=2174; MD −0.05, 95% CI −0.16 to 0.05, I2=79%).

Conclusion

Acute and chronic prenatal exercise reduced maternal circulating blood glucose concentrations, with a larger effect in women with diabetes.

Effects of prenatal exercise on fetal heart rate, umbilical and uterine blood flow: a systematic review and meta-analysis

OBJECTIVE

To perform a systematic review and meta-analysis examining the influence of acute and chronic prenatal exercise on fetal heart rate (FHR) and umbilical and uterine blood flow metrics.

DESIGN

Systematic review with random-effects meta-analysis and meta-regression.

DATA SOURCES

Online databases were searched up to 6 January 2017.

STUDY ELIGIBILITY CRITERIA

Studies of all designs were included (except case studies) if published in English, Spanish or French, and contained information on the population (pregnant women without contraindication to exercise), intervention (subjective or objective measures of frequency, intensity, duration, volume or type of exercise, alone ["exercise-only"] or in combination with other intervention components [eg, dietary; "exercise + co-intervention"]), comparator (no exercise or different frequency, intensity, duration, volume and type of exercise) and outcomes (FHR, beats per minute (bpm); uterine and umbilical blood flow metrics (systolic:diastolic (S/D) ratio; Pulsatility Index (PI); Resistance Index (RI); blood flow, mL/min; and blood velocity, cm/s)).

RESULTS

'Very low' to 'moderate' quality evidence from 91 unique studies (n=4641 women) were included. Overall, FHR increased during (mean difference (MD)=6.35bpm; 95% CI 2.30 to 10.41, I²=95%, p=0.002) and following acute exercise (MD=4.05; 95% CI 2.98 to 5.12, I²=83%, p<0.00001). The incidence of fetal bradycardia was low at rest and unchanged with acute exercise. There were no significant changes in umbilical or uterine S/D, PI, RI, blood flow or blood velocity during or following acute exercise sessions. Chronic exercise decreased resting FHR and the umbilical artery S/D, PI and RI at rest.

CONCLUSION

Acute and chronic prenatal exercise do not adversely impact FHR or uteroplacental blood flow metrics.

N° 367-2019 Lignes Directrices Canadiennes Sur L'activité Physique Durant La Grossesse

OBJECTIF

L'objectif est de guider les femmes enceintes et les professionnels de l'obstétrique et de l'exercice en ce qui concerne l'activité physique prénatale. RéSULTATS: Les issues évaluées étaient la morbidité maternelle, fœtale ou néonatale et la mortalité fœtale pendant et après la grossesse. DONNéES: Nous avons interrogé MEDLINE, Embase, PsycINFO, la Cochrane Database of Systematic Reviews, le Cochrane Central Register of Controlled Trials, Scopus et la Web of Science Core Collection, CINAHL Plus with Full Text, Child Development & Adolescent Studies, ERIC, SPORTDiscus, ClinicalTrials.gov de leur création jusqu'au 6 janvier 2017. Les études primaires de tous types étaient admissibles, à l'exception des études de cas. Seules les publications en anglais, en espagnol et en français ont été retenues. Les articles liés à l'activité physique durant la grossesse qui abordaient la morbidité maternelle, fœtale ou néonatale ou la mortalité fœtale étaient admissibles. La qualité des données probantes a été évaluée au moyen de l'approche GRADE (Grading of Recommendations Assessment, Development and Evaluation).

VALEURS

Le groupe d'experts responsable des lignes directrices a recueilli les commentaires d'utilisateurs finaux (fournisseurs de soins obstétricaux, professionnels de l'exercice, chercheurs, organismes responsables de politiques, et femmes enceintes et en période postpartum). La directive clinique a été élaborée au moyen de l'outil Appraisal of Guidelines for Research Evaluation (AGREE) II. AVANTAGES, INCONVéNIENTS, ET COûTS: Les avantages de l'activité physique prénatale sont modérés, et aucun inconvénient n'a été relevé; la différence entre les conséquences désirables et indésirables (avantage net) devrait donc être modérée. La majorité des intervenants et des utilisateurs finaux ont indiqué qu'il serait faisable, acceptable et équitable de suivre ces recommandations, qui nécessitent généralement des ressources minimes de la part des personnes et des systèmes de santé. PRÉAMBULE: Les présentes lignes directrices contiennent des recommandations fondées sur des données probantes au sujet de l'activité physique durant la grossesse visant à favoriser la santé maternelle, fœtale et néonatale. En l'absence de contre-indications (voir la liste détaillée plus loin), le fait de suivre ces lignes directrices est associé à : 1) moins de complications pour le nouveau-né (p. ex., gros par rapport à l'âge gestationnel); et 2) des bienfaits pour la santé maternelle (p. ex., diminution du risque de prééclampsie, d'hypertension gravidique, de diabète gestationnel, de césarienne, d'accouchement opératoire, d'incontinence urinaire, de gain de poids excessif durant la grossesse et de dépression; amélioration de la glycémie; diminution du gain de poids total durant la grossesse; et diminution de la gravité des symptômes dépressifs et de la douleur lombo-pelvienne). L'activité physique n'est pas associée à la fausse couche, à la mortinaissance, au décès néonatal, à l'accouchement prématuré, à la rupture prématurée préterme des membranes, à l'hypoglycémie néonatale, au poids insuffisant à la naissance, aux anomalies congénitales, au déclenchement du travail, ou aux complications à la naissance. En général, une augmentation de l'activité physique (fréquence, durée ou volume) est liée à une augmentation des bienfaits. Cependant, nous n'avons pas trouvé de données probantes concernant l'innocuité ou l'avantage accru de l'exercice à des niveaux considérablement supérieurs aux recommandations. L'activité physique prénatale devrait être vue comme un traitement de première ligne pour réduire le risque de complications de la grossesse et améliorer la santé physique et mentale de la mère. Pour les femmes enceintes qui n'atteignent actuellement pas le niveau recommandé, nous recommandons une augmentation progressive pour l'atteindre. Les femmes déjà actives peuvent continuer de l'être tout au long de la grossesse. Elles pourraient devoir modifier le type d'activité à mesure que leur grossesse avance. Il peut devenir impossible de suivre les lignes directrices pendant certaines périodes en raison de la fatigue ou des inconforts de la grossesse; nous encourageons les femmes à faire ce qu'elles peuvent et à revenir aux recommandations lorsqu'elles en sont capables. Les recommandations qui suivent reposent sur une revue systématique approfondie de la littérature, l'opinion d'experts, la consultation d'utilisateurs finaux et des considérations de faisabilité, d'acceptabilité, de coût et d'équité.

RECOMMANDATIONS

Les recommandations des Lignes directrices canadiennes sur l'activité physique durant la grossesse 2019 sont fournies ci-dessous avec des énoncés indiquant la qualité des données probantes utilisées et la force des recommandations (des explications suivent).

CONTRE-INDICATIONS

Toutes les femmes enceintes peuvent faire de l'activité physique durant la grossesse, sauf celles qui présentent des contre-indications (voir ci-dessous). Celles présentant des contre-indications absolues peuvent poursuivre leurs activités quotidiennes habituelles, mais ne devraient pas faire d'activités plus vigoureuses. Celles présentant des contre-indications relatives devraient discuter des avantages et des inconvénients de l'activité physique d'intensité modérée à vigoureuse avec leur fournisseur de soins obstétricaux avant d'y prendre part.

CONTRE-INDICATIONS ABSOLUES

Contre-indications relatives  FORCE DES RECOMMANDATIONS: Nous avons utilisé le système GRADE pour évaluer la force des recommandations. Les recommandations sont jugées fortes ou faibles en fonction de : 1) l'équilibre entre les avantages et les inconvénients; 2) la qualité globale des données probantes; 3) l'importance des issues (valeurs et préférences des femmes enceintes); 4) l'utilisation de ressources (coût); 5) l'incidence sur l'équité en matière de santé; 6) la faisabilité et 7) l'acceptabilité. Recommandation forte : La majorité ou la totalité des femmes enceintes auraient avantage à suivre la recommandation. Recommandation faible : Les femmes enceintes n'auraient pas toutes avantage à suivre la recommandation; il faut tenir compte d'autres facteurs comme la situation, les préférences, les valeurs, les ressources et le milieu de chaque personne. La consultation d'un fournisseur de soins obstétricaux peut faciliter la prise de décisions. QUALITé DES DONNéES PROBANTES: La qualité des données probantes fait référence au degré de confiance dans les données et va de très faible à élevée. Qualité élevée : Le groupe d'experts responsable des lignes directrices est très convaincu que l'effet estimé de l'activité physique sur l'issue de santé est près de l'effet réel. Qualité moyenne : Le groupe d'experts responsable des lignes directrices a moyennement confiance en l'effet estimé de l'activité physique sur l'issue de santé; l'effet estimé est probablement près de l'effet réel, mais il est possible qu'il soit très différent. Qualité faible : Le groupe d'experts responsable des lignes directrices a peu confiance en l'effet estimé de l'activité physique sur l'issue de santé; l'effet estimé pourrait être très différent de l'effet réel. Qualité très faible : Le groupe d'experts responsable des lignes directrices a très peu confiance en l'effet estimé de l'activité physique sur l'issue de santé; l'effet estimé est probablement très différent de l'effet réel. ^a Il s'agit d'une recommandation faible parce que la qualité des données probantes était faible et que l'avantage net entre les femmes qui étaient physiquement actives et celles qui ne l'étaient pas était petit. ^b Il s'agit d'une recommandation forte parce que, malgré le fait que les données probantes appuyant l'activité physique durant la grossesse pour les femmes en surpoids ou obèses étaient de qualité faible, des données tirées d'essais cliniques randomisés démontraient une diminution du gain de poids durant la grossesse et une amélioration de la glycémie. ^c On parle d'intensité modérée lorsque l'activité est assez intense pour augmenter la fréquence cardiaque de façon perceptible; une personne peut parler, mais pas chanter durant les activités de cette intensité. Pensons par exemple à la marche rapide, à la gymnastique aquatique, au vélo stationnaire (effort modéré), à l'entraînement musculaire, au port de charges modérées et aux travaux ménagers (p. ex., jardinage, lavage de fenêtres). ^d Il s'agit d'une recommandation faible parce que l'incontinence urinaire n'était pas jugée comme étant une issue « critique » et que les données étaient de qualité faible. ^e Il s'agit d'une recommandation faible parce que : 1) la qualité des données probantes était très faible; et 2) bien que nous ayons étudié les inconvénients, il y avait peu de renseignements disponibles sur l'équilibre entre les avantages et les inconvénients. Cette recommandation était principalement fondée sur l'opinion d'experts.

Is supine exercise associated with adverse maternal and fetal outcomes? A systematic review

OBJECTIVE

Theoretical concerns regarding the supine position at rest due to the gravid uterus obstructing aorta and vena caval flow may impinge uterine blood flow (UBF) to the fetus and maternal venous return.

DESIGN

Systematic review.

DATA SOURCES

Online databases up to 11 December 2017.

STUDY CRITERIA

Eligible population (pregnant without contraindication to exercise), intervention (frequency, intensity, duration, volume or type of supine exercise), comparator (no exercise or exercise in left lateral rest position, upright posture or other supine exercise), outcomes (potentially adverse effects on maternal blood pressure, cardiac output, heart rate, oxygen saturation, fetal movements, UBF, fetal heart rate (FHR) patterns; adverse events such as bradycardia, low birth weight, intrauterine growth restriction, perinatal mortality and other adverse events as documented by study authors), and study design (except case studies and reviews) published in English, Spanish, French or Portuguese.

RESULTS

Seven studies (n=1759) were included. 'Very low' to 'low' quality evidence from three randomised controlled trials indicated no association between supervised exercise interventions that included supine exercise and low birth weight compared with no exercise. There was 'very low' to 'low' quality evidence from four observational studies that showed no adverse events in the mother; however, there were abnormal FHR patterns (as defined by study authors) in 20 of 65 (31%) fetuses during an acute bout of supine exercise. UBF decreased (13%) when women moved from left lateral rest to acute dynamic supine exercise.

CONCLUSION

There was insufficient evidence to ascertain whether maternal exercise in the supine position is safe or should be avoided during pregnancy.