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

The WOMBS Framework: A review and new theoretical model for investigating pregnancy-related weight stigma and its intergenerational implications

As the growing weight stigma literature has developed, one critically relevant and vulnerable population has received little consideration-pregnant and postpartum women. Because weight fluctuations are inherent to this life phase, and rates of prepregnancy overweight and obesity are already high, this gap is problematic. More recently, however, there has been a rising interest in pregnancy-related weight stigma and its consequences. This paper therefore sought to (a) review the emerging research on pregnancy-related weight stigma phenomenology and (b) integrate this existing evidence to present a novel theoretical framework for studying pregnancy-related weight stigma. The Weight gain, Obesity, Maternal-child Biobehavioral pathways, and Stigma (WOMBS) Framework proposes psychophysiological mechanisms linking pregnancy-related weight stigmatization to increased risk of weight gain and, in turn, downstream childhood obesity risk. This WOMBS Framework highlights pregnant and postpartum women as a theoretically unique at-risk population for whom this social stigma engages maternal physiology and transfers obesity risk to the child via social and physiological mechanisms. The WOMBS Framework provides a novel and useful tool to guide the emerging pregnancy-related weight stigma research and, ultimately, support stigma-reduction efforts in this critical context.

Influence of a Virtual Exercise Program throughout Pregnancy during the COVID-19 Pandemic on Perineal Tears and Episiotomy Rates: A Randomized Clinical Trial

The complications associated with COVID-19 confinement (impossibility of grouping, reduced mobility, distance between people, etc.) influence the lifestyle of pregnant women with important associated complications regarding pregnancy outcomes. Therefore, perineal traumas are the most common obstetric complications during childbirth. The aim of the present study was to examine the influence of a supervised virtual exercise program throughout pregnancy on perineal injury and episiotomy rates during childbirth. A randomized clinical trial design (NCT04563065) was used. Data were collected from 98 pregnant women without obstetric contraindications who attended their prenatal medical consultations. Women were randomly assigned to the intervention (IG, N = 48) or the control group (CG, N = 50). A virtual and supervised exercise program was conducted from 8-10 to 38-39 weeks of pregnancy. Significant differences were found between the study groups in the percentage of episiotomies, showing a lower episiotomy rate in the IG (N = 9/12%) compared to the CG (N = 18/38%) (χ² (3) = 4.665; p = 0.031) and tears (IG, N = 25/52% vs. CG, N = 36/73%) (χ² (3) = 4.559; p = 0.033). A virtual program of supervised exercise throughout pregnancy during the current COVID-19 pandemic may help reduce rates of episiotomy and perineal tears during delivery in healthy pregnant women.

Body mass index and physical activity in seven-year-old children whose mothers exercised during pregnancy: follow-up of a multicentre randomised controlled trial

BACKGROUND

There are limited data on long-term outcomes of children whose mothers have followed exercise interventions during pregnancy. The aim of this paper was to investigate whether regular moderate intensity exercise during pregnancy affected the children's body mass index (BMI) and physical activity (PA) at 7 years of age, and determine the relationship between children's and mothers' BMI and PA.

METHODS

This was a follow-up of a multicentre randomised controlled trial, carried out at St. Olavs Hospital, Trondheim University Hospital, and Stavanger University Hospital, Norway (2007-2009 and 2014-2016). Women were randomised to follow a 12-week structured exercise protocol or standard antenatal care during pregnancy. At the 7-year follow-up, parents reported their child's height, weight, and PA. The mothers also reported their own weight and PA. Main outcome variables were BMI, frequency and duration of moderate to vigorous PA (MVPA), and intensity of PA.

RESULTS

A total of 855 women were randomised to exercise (n = 429) or standard antenatal care (n = 426) during pregnancy. At follow-up, 164 (38.2%) children and mothers in the intervention group and 117 (27.5%) in the control group participated. We found no group differences in the children's iso-BMI or PA. Findings were similar when we performed stratified analyses by sex, except boys in the control group spent more time on electrical devices than boys in the intervention group. Subgroup analyses of children of mothers who adhered to the exercise protocol and sensitivity analyses excluding children born preterm, children admitted to the neonatal intensive care unit, and children with diseases or health problems at the 7-year follow-up, did not change the results. Children's BMI, weekly leisure time MVPA and intensity of PA correlated with mothers' BMI, daily exercise, and intensity of exercise.

CONCLUSIONS

Regular moderate intensity exercise during pregnancy did not affect BMI or PA of the children at 7 years. Good maternal health should be encouraged as it may influence the health of the next generation.

TRIAL REGISTRATION

The initial RCT study was registered in ClinicalTrials.gov NCT00476567 .

Breath of Life: Heart Disease Link to Developmental Hypoxia

Heart disease remains one of the greatest killers. In addition to genetics and traditional lifestyle risk factors, we now understand that adverse conditions during pregnancy can also increase susceptibility to cardiovascular disease in the offspring. Therefore, the mechanisms by which this occurs and possible preventative therapies are of significant contemporary interest to the cardiovascular community. A common suboptimal pregnancy condition is a sustained reduction in fetal oxygenation. Chronic fetal hypoxia results from any pregnancy with increased placental vascular resistance, such as in preeclampsia, placental infection, or maternal obesity. Chronic fetal hypoxia may also arise during pregnancy at high altitude or because of maternal respiratory disease. This article reviews the short- and long-term effects of hypoxia on the fetal cardiovascular system, and the importance of chronic fetal hypoxia in triggering a developmental origin of future heart disease in the adult progeny. The work summarizes evidence derived from human studies as well as from rodent, avian, and ovine models. There is a focus on the discovery of the molecular link between prenatal hypoxia, oxidative stress, and increased cardiovascular risk in adult offspring. Discussion of mitochondria-targeted antioxidant therapy offers potential targets for clinical intervention in human pregnancy complicated by chronic fetal hypoxia.

Metabolomics to understand placental biology: Where are we now?

Metabolomics, the application of analytical chemistry methodologies to survey the chemical composition of a biological system, is used to globally profile and compare metabolites in one or more groups of samples. Given that metabolites are the terminal end-products of cellular metabolic processes, or 'phenotype' of a cell, tissue, or organism, metabolomics is valuable to the study of the maternal-fetal interface as it has the potential to reveal nuanced complexities of a biological system as well as differences over time or between individuals. The placenta acts as the primary site of maternal-fetal exchange, the success of which is paramount to growth and development of offspring during pregnancy and beyond. Although the study of metabolomics has proven moderately useful for the screening, diagnosis, and understanding of the pathophysiology of pregnancy complications, the placental metabolome in the context of a healthy pregnancy remains poorly characterized and understood. Herein, we discuss the technical aspects of metabolomics and review the current literature describing the placental metabolome in human and animal models, in the context of health and disease. Finally, we highlight areas for future opportunities in the emerging field of placental metabolomics.

Relationships between Objectively Measured Sedentary Behavior during Pregnancy and Infant Birthweight

Background: Although numerous studies have assessed physical activity during pregnancy and relationships with infant outcomes, such as birthweight, few have evaluated sedentary behavior. Our objective was to evaluate sedentary behavior across pregnancy and relationships with infant birthweight in a sociodemographically diverse sample. Methods: We measured device-assessed sedentary behavior and physical activity over three days at 16–18, 24–26, and 32–34 weeks gestation and infant birthweight from medical records among 71 participants. We used linear regression to assess relationships between sedentary behavior at each evaluation period with birthweight-for-gestational age Z-scores (BW-for-GA). Results: There were no linear relationships between sedentary behavior and BW-for-GA at any evaluation period. We observed a modest curvilinear relationship between sedentary behavior at 16–18 weeks and BW-for-GA (R² = 0.073, p = 0.021). Low and high levels of sedentary behavior predicted lower BW-for-GA. Multivariate models suggested that this relationship was independent of physical activity levels. Conclusions: Considering the high levels of sedentary behavior during pregnancy observed in many studies, even modest associations with birthweight merit further consideration. Relationships might not be evident later in pregnancy or if only linear relationships are considered. More detailed studies could help guide recommendations on sedentary behavior during pregnancy and the development of more comprehensive interventions.

Moderate intensity aerobic exercise during pregnancy and 1-month infant Morphometry

OBJECTIVE

Assess the effects of supervised, prenatal aerobic exercise intervention on 1-month-old neonatal morphometry.

METHODS

Secondary data analyses of a 24+ week, randomized controlled exercise intervention trial in pregnant women between 2015 and 2018 were performed. Eligibility criteria included pregnant women: <16 weeks of gestation, singleton pregnancy, aged 18-40 years, and body mass index of 18.5-35.00 kg∙m² . Eligible pregnant women (n = 128) were randomly assigned a moderate-intensity aerobic exercise group (n = 68) or a nonexercising group (n = 60) consisting of light stretching and breathing techniques. Neonatal weight, skinfold thickness, circumferences, and fat-free mass were measured at 1-month of age. Covariates included weight gain, gestational diabetes mellitus, and neonatal sex. ANCOVAs for intention-to-treat (ITT) and per protocol were performed.

RESULTS

ITT and per protocol analyses included 74 and 56 participants, respectively. Adjusted regression results showed significant between-group differences for neonatal skinfold thickness (ITT: 20.0 mm vs. 22.2 mm; p = .04; per protocol: 19.8 mm vs. 22.3 mm; p = .03) and body fat (per protocol 13.2% vs. 15.1%; p = .05). No between-group differences for weight (p = .36, .25), abdominal (p = .08, .35) and mid-upper arm circumferences (p = .30, .26), or fat-free mass (p = .83, .69).

CONCLUSION

The study findings suggest that aerobic exercise has a beneficial impact on neonatal skinfold thickness and percent body fat at 1 month of age. Participation in the recommended levels of aerobic exercise (150 min, moderate-intensity per week) throughout the prenatal period may serve as an effective strategy to reduce the risk of overweight or obesity in the early postnatal period.

Association Between Pregnancy-Related Hormones and Lumbopelvic Pain Characteristics in Pregnant Women: A Scoping Review

OBJECTIVES

The objectives of this scoping review were (1) to document and quantify the potential associations between lumbopelvic pain characteristics and pregnancy-related hormones, and (2) to identify research approaches and assessment tools used to investigate lumbopelvic pain characteristics and pregnancy-related hormones.

METHODS

The literature search was conducted in 6 databases (MEDLINE, Academic Search Complete, Cumulative Index to Nursing and Allied Health Literature, SportDiscus, PsycINFO, and Cochrane) from inception up to March 2020 and completed using search terms relevant to pregnant women, pregnancy-related hormones, and lumbopelvic pain. The risk of bias was assessed using the characteristics recommended by Guyatt et al. for observational studies.

RESULTS

The search yielded 1015 publications from which 9 met the inclusion criteria. Relaxin was the most studied pregnancy-related hormone. An association between relaxin levels and lumbopelvic pain presence or severity was found in 4 studies, while 5 studies did not report an association between them. One study reported an association between relaxin and lumbopelvic pain presence or severity while 2 studies reported no association and were considered as having a low risk of bias. One study reported measures of estrogen and progesterone levels. It showed that progesterone levels were found to be significantly higher in pregnant women with lumbopelvic pain compared to those without, while estrogen concentrations were similar in both groups.

CONCLUSION

The literature showed conflicting evidence regarding the association between pregnancy-related hormones and lumbopelvic pain characteristics in pregnant women. The assessment tools used to investigate lumbopelvic pain characteristics and pregnancy-related hormones are heterogeneous across studies. Based on limited and conflicting evidence, and due to the heterogeneity of assessment tools and overall poor quality of the literature, the association between pregnancy-related hormones and lumbopelvic pain characteristics is unclear.

Exercise in Pregnancy Increases Placental Angiogenin without Changes in Oxidative or Endoplasmic Reticulum Stress

PURPOSE

Despite immense research highlighting maternal-fetal benefits of exercise during pregnancy, there remain concerns that exercise may undermine placental function. Although maternal exercise has demonstrated favorable aerobic conditioning responses in the mother, it is not known whether maternal exercise promotes increased angiogenesis in the placenta, perhaps at the expense of impaired endoplasmic reticulum (ER) homeostasis and/or oxidative stress. We investigated if a mild (30% heart rate reserve) and/or moderate (70% heart rate reserve) exercise regime in healthy pregnant women affected placental markers of angiogenesis, ER stress, and oxidative stress. We hypothesized that the improved aerobic conditioning of mothers who exercise is beneficial to enhance placental angiogenesis and normal maternal-fetal outcomes.

METHODS

Placental tissues were collected within 1 h of delivery from a convenience sample of 29 healthy mothers of full-term infants. Twenty-one women participated in routine exercise from midgestation (16-20 wk) until term of either mild or moderate intensity, whereas eight sedentary women served as controls.

RESULTS

No differences were identified between groups including gestational length, fetal-placental weight ratio, or APGAR scoring. All exercisers exhibited a significant 20-fold increase in the mRNA (as assessed by quantitative real-time polymerase chain reaction) and a 10-fold increase in the protein expression of angiogenin (e.g., ANG1) in the placenta. However, in both exercising groups, no increases in placental markers (i.e., HIF1α, VEGF), ER stress (i.e., spliced XBP1, ATF4, ATF6, CHOP, and BAX), or oxidative stress (i.e., SOD1, SOD2) were observed.

CONCLUSIONS

Overall, our study suggests that mild- and moderate-intensity exercise increases angiogenesis but does not increase placental oxidative or ER stress in healthy pregnancies, bolstering support for routine exercise as a part of standard care in pregnant women. Future studies are warranted to investigate the potential benefits of exercise on ANG1 in pathological pregnancies.

Acute fetal response to high-intensity interval training in the second and third trimesters of pregnancy

The majority of women do not meet the recommended levels of exercise during their pregnancies, frequently due to a lack of time. High-intensity interval training offers a potential solution, providing an effective, time-efficient exercise modality. This exercise modality has not been studied in pregnancy therefore, the objective of this study was to evaluate fetal response to a high-intensity interval training resistance circuit in the late second and early third trimesters of pregnancy. Fourteen active, healthy women with uncomplicated, singleton pregnancies participated in a high-intensity interval training resistance circuit between 28 + 0/7 and 32 + 0/7 weeks. A Borg rating of perceived exertion of 15-17/20 and an estimated heart rate of 80%-90% of maternal heart-rate maximum was targeted. Fetal well-being was evaluated continuously with fetal heart-rate tracings and umbilical artery Doppler velocimetry conducted pre-and post-exercise. Fetal heart rate tracings were normal throughout the exercise circuit. Post-exercise, umbilical artery end-diastolic flow was normal and significant decreases were observed in the mean systolic/diastolic ratios, pulsatility indexes and resistance indexes. Therefore, in a small cohort of active pregnant women, a high-intensity interval training resistance circuit in the late second and early third trimesters of pregnancy appears to be a safe exercise modality with no acute, adverse fetal effects but further study is required. Novelty: High-intensity interval training, at an intensity in excess of current recommendations, does not appear to be associated with any adverse fetal effects in previously active pregnant women. High-intensity interval training is an enjoyable and effective exercise modality in previously active pregnant women.

Effect of a dietary and exercise intervention in women with overweight and obesity undergoing fertility treatments: protocol for a randomized controlled trial

BACKGROUND

Distinct molecular, inflammatory, and metabolic signatures are present in oocytes and follicular fluid derived from women with obesity when compared to those derived from normal weight women, which suggest existing signals that may program future offspring for metabolic diseases. This study aims to assess the feasibility and efficacy of a peri-conception nutrition and exercise intervention on mitigating obesity-associated changes in oocyte gene expression profiles and follicular fluid metabolites.

METHODS

This single blinded randomized control trial will include 120 women with a BMI of 25-45 kg/m², ≥21 years of age, and undergoing in vitro fertilization (IVF) treatments. Participants will be randomized to standard of care (N = 60) or an intervention group (N = 60) in a block design by polycystic ovary syndrome status. The intervention will combine a dietary component (Mediterranean meal plan) with exercise prescription following the Physical Activity Guidelines for Americans. Participants will be assessed pre- and post-intervention. The standard of care group will be offered to join the intervention group if the IVF treatments are unsuccessful as a cross over design. Recruitment is anticipated to start in July of 2021. Primary outcomes will include single oocyte gene expression profiles and follicular fluid metabolites. Mann-Whitney U nonparametric tests will be used to assess potential differences for each stratum. Follicular fluid and serum metabolites will be analyzed using a one-factor Analysis of Covariance (ANCOVA) at four levels, pair-wise comparisons using Tukey-Kramer post-hoc tests will be used to identify groups whose means differ significantly while retaining the family-wise error rate at 5%. When the design is balanced, two-way Analysis of Variance (ANOVA), or non-parametric Friedman test will be used in data analysis. Additionally, general linear models and ANCOVA may be used to control for covariates. Significance will be set at p < 0.05. Findings will be disseminated via peer-reviewed manuscripts and presentations at scientific conferences.

DISCUSSION

This study will provide novel data and key information on the impact of a dietary and exercise intervention on oocyte gene expression and follicular fluid content. Results will demonstrate the potential of such intervention in mitigating obesity-induced changes in oocyte gene expression and follicular fluid metabolites.

TRIAL REGISTRATION

ClinicalTrials.gov ( NCT04273048 ): submitted November 13, 2019; posted February 17, 2020.

Lifestyle Habits among Pregnant Women in Denmark during the First COVID-19 Lockdown Compared with a Historical Period-A Hospital-Based Cross-Sectional Study

The first national lockdown in Denmark due to the COVID-19 pandemic was declared on 11 March 2020. From this date, national restrictions were imposed. We aimed to assess the potential influence of this first nationwide lockdown on exercise, alcohol consumption, and smoking in early pregnancy. Using a cross-sectional study based on routinely collected patient-reported data, we compared the lifestyle habits of women who were pregnant during the first phase of the pandemic (COVID-19 group) (n = 685) with those of women who were pregnant the year before (Historical group) (n = 787). We found a reduction in any exercise (PR = 0.91, 95% CI (0.84 to 0.99), in adherence to national recommendations of exercise (PR = 0.89, 95% CI (0.80 to 0.99), in cycling (15% vs. 28%, p < 0.0001), and swimming (0.3% vs. 3%, p = 0.0002) in the COVID-19 group compared with the Historical group. The prevalence of binge drinking was reduced in the COVID-19 group compared with the Historical group (PR = 0.80, 95% CI (0.68 to 0.93). In contrast, the prevalence of any weekly alcohol consumption and smoking cessation during pregnancy was similar between groups. Our findings indicate that national restrictions due to the COVID-19 pandemic influenced the lifestyle habits of pregnant women and should be addressed in antenatal counseling.

Prenatal Exercise and Cardiovascular Health (PEACH) Study: Impact on the Vascular System

PURPOSE

Healthy pregnancy is typically associated with favorable vascular adaptations to both structure and function of the peripheral arteries. Exercise is independently associated with improvements in peripheral vascular health; however, the impact of exercise on prenatal adaptations is unclear. Therefore, we hypothesized that a structured aerobic exercise intervention between the second and third trimester (TM2 and TM3, respectively) of pregnancy would augment the already-positive changes in vascular outcomes.

METHODS

We recruited 59 inactive pregnant women (<20 weeks gestation) and randomized them into control (standard care; n = 28) or exercise (moderate intensity aerobic exercise, 3-4 days/week, 25-40 minutes, 14 ± 1 weeks; n = 31) conditions. Before and after the intervention all women completed comprehensive peripheral vascular assessment, which included blood markers of vascular health, carotid distensibility metrics, measures of arterial stiffness (pulse wave velocity; PWV), and [superficial] femoral artery reactivity during cold pressor test (CPT).

RESULTS

Carotid artery diameter increased from 6.5 mm to 6.9 mm (p < 0.001) strain (%)decreased from 9.9% to 8.4% (p < 0.001). Carotid artery blood flow, compliance and distensibility coefficients, stiffness (β), distensibility (1/β), and Elastic modulus were not different across gestation. PWV was not different across gestation. Superficial femoral artery diameter was increased from 5.4 mm to 5.6 mm (p = 0.004) while blood flow, conductance, and resistance at rest and during CPT were not different across gestation. None of our measures of vascular health were impacted by exercise.

CONCLUSION

We did not observe an impact of aerobic exercise on altering the changes across pregnancy in blood vessel health. However, the present study was conducted in women who were overall at low risk for developing gestational hypertension and should be interpreted with caution. Future work in high-risk women is needed.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Prenatal exercise and cardiovascular health (PEACH) study: The remote effect of aerobic exercise training on conduit artery and resistance vessel function

We assessed the impact of a structured lower-limb aerobic exercise training intervention during pregnancy on brachial artery endothelial function, shear rate and patterns, and forearm blood flow and reactive hyperemia. Twenty-seven pregnant women were recruited and randomized into either a control group (n=11; 31.0 ± 0.7 years), or an exercise intervention group (n=16; 32.6 ± 0.9 years; NCT02948439). The exercise group completed 40 minutes of aerobic exercise (50-70% heart rate reserve) 3-4 times per week, between the second and third trimester of pregnancy. Endothelial function was assessed using flow-mediated dilation (FMD, normalized for shear stress) pre- (16-20 weeks) and post-intervention (34-36 weeks). The exercise training group experienced an attenuated increase in mean arterial pressure (MAP) relative to the control group (∆MAP exercise: +2± 2 mmHg vs. control: +7±3 mmHg; p=0.044) from pre- to post-intervention. % FMD change corrected for shear stress was not different between groups (p=0.460); however, the post occlusion mean flow rate (exercise: 437±32 mL/min vs. control: 364±35 mL/min; p=0.001) and post occlusion anterograde flow rate (exercise: 438±32 mL/min vs. control: 364±46 mL/min;p=0.001) were larger for the exercise training group compared to controls, post-intervention. Although endothelial function was not different between groups, we observed an increase in microcirculatory dilatory capacity, as suggested by the augmented reactive hyperemia in the exercise training group. Novelty: • Endothelial function was not altered with exercise training during pregnancy. • Exercise training did contribute to improved cardiovascular outcomes, which may have been associated with augmented reactive hyperaemia, indicative of increased microcirculatory dilatory capacity.

Effects of Maternal Exercise During Pregnancy on Perinatal Growth and Childhood Obesity Outcomes: A Meta-analysis and Meta-regression

BACKGROUND

Perinatal growth abnormalities program susceptibility to childhood obesity, which is further exaggerated by maternal overweight and obesity (MO) during pregnancy. Exercise is highly accessible, but reports about the benefits of maternal exercise on fetal growth and childhood obesity outcomes are inconsistent, reducing the incentives for pregnant women to participate in exercise to improve children's perinatal growth.

OBJECTIVE

This systematic review and meta-analysis aims to establish evidence-based efficacy of exercise in mothers with normal weight (MNW) and MO during pregnancy in reducing the risks of perinatal growth abnormalities and childhood obesity. In addition, the impacts of exercise volume are also assessed.

METHODS

The PubMed, ScienceDirect, Web of Science, and Cochrane Library databases were searched from inception to February 15, 2020. We included randomized controlled trials with exercise-only intervention or exercise with other confounders in pregnant MNW (body mass index, BMI 18.5-24.9 kg/m²) and MO (BMI ≥ 25 kg/m²), which were further subgrouped in the meta-analysis. Primary outcomes included birth weight, preterm birth, small for gestational age (SGA), large for gestational age (LGA), infant and childhood weight, and childhood obesity. A linear meta-regression analysis was also used to explore the effects of exercise volume on outcomes.

RESULTS

99 studies were included in the meta-analysis (n = 596,876), and individual study quality ranged from fair to good according to the Newcastle-Ottawa scale assessment. Exercise only interventions in MNW reduced preterm birth by 15% (26 studies, n = 76,132; odds ratio [OR] 0.85; 95% CI 0.72, 1.01; I² = 83.3%), SGA by 17% (33 studies, n = 92,351; OR 0.83; 95% CI 0.71, 0.98; I² = 74.5%) and LGA by 17% (29 studies, n = 84,310; OR 0.83; 95% CI 0.74, 0.95; I² = 60.4%). Exercise only interventions in MO reduced preterm birth by 33% (2 studies, n = 3,050; OR 0.67; 95% CI 0.70, 0.96; I² = 0%), SGA by 27% (8 studies, n = 3,909; OR 0.73; 95% CI 0.50, 1.05; I² = 40.4%) and LGA by 55% (9 studies, n = 81,581; OR 0.45; 95% CI 0.18, 1.11; I² = 98.3%). Exercise only interventions in MNW reduced childhood obesity by 53% (3 studies, n = 6,920; OR 0.47; 95% CI 0.36, 0.63; I² = 77.0%). However, no significant effect was observed in outcomes from exercise confounders in either MNW or MO. In the meta-regression, the volume of exercise-only intervention in MNW was negatively associated with birth weight, greatly driven by volumes more than 810 metabolic equivalents (MET)-min per week. Other outcomes were not associated with exercise volume.

CONCLUSIONS

This systematic review and meta-analysis suggests that exercise during pregnancy in both MNW and MO safely and effectively reduce the risks of preterm birth, SGA, and LGA. Furthermore, MNW exercise also reduces the risk of childhood obesity. Overall, regardless of prepregnancy BMI, maternal exercise during pregnancy provides an excellent opportunity to mitigate the high prevalence of adverse birth outcomes and childhood obesity.

Circulating small extracellular vesicles increase after an acute bout of moderate-intensity exercise in pregnant compared to non-pregnant women

The physiological and molecular mechanisms linking prenatal physical activity and improvements in maternal–fetal health are unknown. It is hypothesized that small extracellular vesicles (EVs, ~ 10–120 nm) are involved in tissue cross-talk during exercise. We aimed to characterize the circulating small EV profile of pregnant versus non-pregnant women after an acute bout of moderate-intensity exercise. Pregnant (N = 10) and non-pregnant control (N = 9) women performed a single session of moderate-intensity treadmill walking for 30 min. Plasma was collected immediately pre- and post-exercise, and small EVs were isolated by differential ultracentrifugation. EV presence was confirmed by western blotting for the small EV proteins TSG-101 and flottilin-1. Small EVs were quantified by size and concentration using nanoparticle tracking analysis and transmission electron microscopy. All EV fractions were positive for TSG-101 and flotillin-1, and negative for calnexin. Mean vesicle size at baseline and percent change in size post-exercise were not different between groups. At baseline, pregnant women had higher levels of small EVs compared to controls (1.83E+10 ± 1.25E+10 particles/mL vs. 8.11E+09 ± 4.04E+09 particles/mL, respectively; p = 0.032). Post-exercise, small EVs increased significantly in the circulation of pregnant compared to non-pregnant women after correcting for baseline values (64.7 ± 24.6% vs. − 23.3 ± 26.1%, respectively; F = 5.305, p = 0.035). Further research is needed to assess the functional roles of exercise-induced small EVs in pregnancy.

Maternal body-mass-index and neonatal brachial plexus palsy in a California cohort

OBJECTIVE

To evaluate risk factors and describe the association between maternal pre-pregnancy body-mass-index (BMI) and neonatal brachial plexus palsy (BPP) in vaginal deliveries with and without shoulder dystocia.

METHODS

This is a retrospective cohort study of singleton, non-anomalous, term vaginal deliveries in California (2007-2011). Deliveries were classified as with or without shoulder dystocia. Our primary outcome was BPP and the independent variable of interest was maternal pre-pregnancy BMI, which was categorized as underweight (<18.5 kg/m²), normal weight (18.5-24.9 kg/m²), overweight (25-29.9 kg/m²), obesity I (30-34.9 kg/m²), obesity II (35-39.9 kg/m²) and obesity III (≥40 kg/m²). We evaluated demographics, maternal, labor, and neonatal characteristics using chi-squared tests and assessed the association of pre-pregnancy BMI with BPP using multivariable logistic regression models.

RESULTS

In our cohort of 1,395,761 women, there were 21,463 deliveries with shoulder dystocia and 1,374,298 deliveries without shoulder dystocia. Among deliveries with shoulder dystocia, BPP was observed more frequently in neonates born to women with BMI categorized as overweight (32% vs. 29%; p < .001), obesity I (22% vs. 14%; p < .001), obesity II (10% vs. 6%; p < .001), and obesity III (8% vs. 3%; p < .001). After adjusting for confounders, the odds of BPP in deliveries with shoulder dystocia was significantly higher for women who were overweight (aOR = 1.65; 95% CI: 1.35-2.01), obesity I (aOR = 2.33; 95% CI: 1.86-2.90), obesity II (aOR = 2.56; 95% CI: 1.92-3.40), and obesity III (aOR = 3.80; 95% CI: 2.75-5.25). In deliveries without shoulder dystocia, BPP was more common in women with a BMI that was overweight (29% vs. 25%; p < .001), obesity I (17% vs. 11%; p < .001), obesity II (9% vs. 4%; p < .001), and obesity III (8% vs. 2%; p < .001). In this cohort, multivariable regression model showed similar results in women with a BMI that was overweight (aOR = 1.47; 95% CI: 1.19-1.81), obesity I (aOR = 1.99; 95% CI: 1.55-2.54), obesity II (aOR = 2.79; 95% CI: 2.04-3.83), and obesity III (aOR = 5.05; 95% CI: 3.63-7.03).

CONCLUSION

Rising maternal pre-pregnancy BMI is associated with an increased risk of BPP in vaginal deliveries with and without shoulder dystocia. Preconception interventions targeting weight management may be beneficial in reducing BPP in all deliveries.

Cardiac Responses to Prenatal Resistance Exercise with and without the Valsalva Maneuver

PURPOSE

Exercise guidelines recommend incorporating resistance exercise (RE) into a regular aerobic training program during pregnancy. However, few women do so because of uncertainties about the safety of prenatal RE, particularly regarding the Valsalva maneuver (VM). The aim of this study was to determine the acute cardiovascular responses to prenatal RE at different intensities, with and without VM.

METHODS

Healthy pregnant (n = 15; 22.9 ± 5.9 wk of gestation) and nonpregnant women (n = 15) were recruited. Maximal strength over 10 repetitions (10RM) for semireclined leg press was determined. Women underwent standardized assessments of cardiac structure, function and mechanics (echocardiography), heart rate (ECG), and blood pressure (photoplethysmography) at baseline, during RE at 20%, 40%, and 60% 10RM while free-breathing, and at 40% 10RM with VM. Significant differences were identified between subjects at baseline (independent t-tests), between and within subjects during free-breathing RE (general linear model, baseline as a covariate), and between and within subjects for 40% 10RM free-breathing versus VM (mixed-effects model).

RESULTS

Resting cardiac output, heart rate, and stroke volume were greater in pregnant women, without differences in blood pressure, ejection fraction, or cardiac mechanics. During free-breathing RE, pregnant women had a greater ejection fraction compared with nonpregnant women; however, all other hemodynamic variables were not different between groups. Cardiac mechanics during free-breathing RE across all intensities were not different between groups, with the exception that pregnant women had a lower apical circumferential strain that did not affect global cardiac function. No differences were observed between groups during 40% 10RM RE with and without VM.

CONCLUSIONS

Pregnant women have proportionate cardiac responses to light-moderate RE, both with and without the VM. These findings reinforce the safety of RE in healthy pregnancy.

Level of exercise and physical activity among pregnant women in Saudi Arabia: A systematic review

The current study aimed to clarify the health benefits of physical activity on the mother and fetus in the Saudi women population. Besides, it is intended to provide recommendation based on the literature and results of studies from Saudi Arabia for exercise in pregnancy to improve the general health of women in Saudi Arabia. Prenatal physical exercise enhances physical and mental health of pregnant women. It can also reduce the risk of multiple pregnancy-related complications such as; lower back pain, fluid retention and risk of gestational diabetes. All these factors can affect fetal development and life later. Multiple studies showed that prenatal exercise could reduce the risk of fetal macrosomia with no effect on other perinatal or postnatal complications. The study followed the systematic literature review approach where it included multiple medical search Databases using PICOS eligibility criteria up to January 2019. The review was based on the following keywords: pregnancy, gestational, or prenatal) and (physical exercise, exercise, or physical activity. There are only two studies that dealt with physical exercises among Saudi women. The results indicated a relation between prenatal physical exercise on improving or decreasing risks on the mother and child during pregnancy.

Effects on the maternal-fetal health outcomes of various physical activity types in healthy pregnant women. A systematic review and meta-analysis

BACKGROUND

Physical activity (PA) promotes health in pregnancy.

OBJECTIVE

To collate the recent randomized controlled trial (RCT) on the effects of various types of PA during pregnancy on maternal-fetal health outcomes, among healthy mothers, and to report the variability in the outcomes reported.

SEARCH STRATEGY

Registered in PROSPERO (CRD42019143522). Systematic search conducted in EMBASE, CENTRAL, MEDLINE and CINAHL, from 2015-2020.

SELECTION CRITERIA

RCT examining PA interventions and maternal-fetal outcomes.

DATA COLLECTION AND ANALYSIS

Were independently extracted by two reviewers. Quality of studies was assessed with Cochrane Collaboration's risk of bias tool.

RESULTS

37 studies (6857 women) were included. PA had a protective effect on gestational weight gain (overall SMD -0.32, 95 % CI -0.46, -0.17, I² 77 %; supervised exercise SMD -0.15, 95 % CI -0.28, -0.02, I² 51 %; static cycling SMD -0.32, 95 % CI -0.59, -0.05; I² 49 %), gestational diabetes (overall OR 0.65, 95 % CI: 0.43, 0.98, I² 48 %), and hypertensive disorders (overall OR 0.51, 95 % CI: 0.31, 0.83, I² 0%).

CONCLUSIONS

PA in pregnancy had a preventive effect on weight gain, gestational diabetes, and hypertensive disorders. Supervised exercise and static cycling had a protective effect on gestational weight gain. Variation in outcomes reported suggest establishing a core outcome set.

Asia-Pacific consensus on physical activity and exercise in pregnancy and the postpartum period

Physical activity and exercise in pregnancy are generally beneficial and enhance the physical and mental health of women. These benefits also prevent excessive weight gain and reduce risks of obesity in pregnancy, such as gestational diabetes, hypertensive disorders, higher rates of caesarean delivery, macrosomia and stillbirth. Thus, there is a need to optimise perinatal exercise and physical activity globally. There is currently no consensus recommendation on the role of physical activity and exercise in pregnancy and the postpartum period in the Asia-Pacific region. In this paper, we present seven key consensus recommendations on physical activity and exercise in pregnancy and the postpartum period by 18 key members representing 10 countries in Asia-Pacific regions during an international workshop of the Asia

Diabetes in Pregnancy Conference in Singapore on 11–12 January 2020. Through these consensus recommendations, we hope to improve the metabolic health of pregnant women living in Asia-Pacific regions by educating the public and guiding healthcare professionals on the safety and importance of physical exercise and activity to benefit pregnant women and after childbirth.

Sedentary behaviour and physical activity across pregnancy and birth outcomes

BACKGROUND

Shorter gestation or smaller birth size are indicators of a suboptimal fetal environment and negatively impact short- and long-term offspring health. Understanding how modifiable maternal behaviours, such as moderate-to-vigorous intensity physical activity (MVPA) or sedentary behaviour (SED), improve fetal outcomes could inform strategies to improve health across the lifespan.

OBJECTIVES

The objective of this study was to examine the association of MVPA and SED across pregnancy trimesters on gestational age at delivery and newborn anthropometrics.

METHODS

The MoM Health Study measured SED (thigh-mounted activPAL3 micro) and MVPA (waist-worn Actigraph GTX3) in each trimester of pregnancy. Birth outcomes (gestational age at delivery, birthweight, birth length, and head circumference) were abstracted from medical records and used to calculate ponderal index (grams*100/cm³ ) and size-for-gestational age percentiles. Associations of group-based trajectories and trimester-specific SED and MVPA with birth outcomes were analysed using regression models.

RESULTS

Low, medium, and high trajectory groups were generated SED and MVPA in 103 and 99 pregnant women, respectively. High vs low SED trajectory was associated with earlier gestational age at delivery (β -1.03 weeks, 95% CI -2.01, -0.06), larger head circumference (β 0.83 cm, 95% CI 0.24, 1.63), longer birth length (β 1.37 cm, 95% CI 0.09, 2.64), and lower ponderal index (β -0.24 g*100/cm³ , 95% CI -0.42, -0.06), after adjustment for demographics, pre-pregnancy BMI, and (for newborn anthropometric outcomes) gestational age. The association of high SED with lower ponderal index was the most robust across progressively adjusted models (β -0.25 g*100/cm³ , 95% CI -0.44, -0.07). SED trajectory was not associated with birthweight or size-for-gestational age. High vs low MVPA trajectory was only associated with smaller head circumference (β -0.86 cm, 95% CI -1.70, -0.02).

CONCLUSIONS

Higher SED during pregnancy may result in shorter gestation and inhibited fetal growth. Further research evaluating the effect of reducing SED during pregnancy on birth outcomes is warranted.

Misreporting of Physical Activity and Sedentary Behavior in Parents-to-Be: A Validation Study across Sex

This study validated the International Physical Activity Questionnaire (IPAQ) and the Context-specific Sedentary Behavior Questionnaire (CSBQ) against accelerometry among parents-to-be. Sex-differences in potential misreporting of physical activity (PA) and sedentary behavior (SB) were also investigated. Self-reported total PA (TPA), light-intensity PA (LPA), moderate-intensity PA (MPA), vigorous-intensity PA (VPA), moderate-to-vigorous-intensity PA (MVPA), and SB of 91 parents-to-be (41 men and 50 women) were compared with Actigraph data according to sex. Furthermore, the extent of misreporting was compared between sexes. Strong correlations for TPA and weak-to-moderate correlations for LPA, MPA, VPA, MVPA, and SB were observed. Participants underestimated TPA by 1068 min/week (=17.8 h/week; −50%), LPA by 1593 min/week (=26.6 h/week; −83%), and SB by 428 min/week (=7.1 h/week; −11%) and overestimated MPA by 384 min/week (=6.4 h/week; +176%) and MVPA by 525 min/week (=8.8 h/week; +224%). Males overreported VPA more than females in absolute minutes per week (238 min/week, i.e., 4.0 h/week vs. 62 min/week, i.e., 1.0 h/week), whereas, in relative terms, the opposite (+850% vs. +1033%) was true. The IPAQ and CSBQ can be used with caution to estimate TPA and SB among parents-to-be considering a strong correlation but low agreement for TPA and a weak-to-moderate correlation but acceptable agreement for SB. We disadvise using these self-reports to estimate PA on the distinct intensity levels.

Does exercise during pregnancy impact organs or structures of the maternal-fetal interface?

Exercise during pregnancy has been shown to be associated with improved health outcomes both during and after pregnancy for mother and fetus across the lifespan. Increasing physical activity and reducing sedentary behaviour during pregnancy have been recommended by many researchers and clinicians-alike. It is thought that the placenta plays a central role in mediating any positive or negative pregnancy outcomes. The positive outcomes obtained through prenatal exercise are postulated to result from exercise-induced regulation of maternal physiology and placental development. Considerable research has been performed to understand the placenta's role in pregnancy-related diseases, such as preeclampsia, fetal growth restriction, and gestational diabetes mellitus. However, little research has examined the potential for healthy lifestyle and behavioural changes to improve placental growth, development, and function. While the placenta represents the critical maternal-fetal interface responsible for all gas, nutrient, and waste exchange between the mother and fetus, the impact of exercise during pregnancy on placental biology and function is not well known. This review will focus on prenatal exercise and its promising influence on the structures of the maternal-fetal interface, with particular emphasis on the placenta. Potential molecular mechanistic hypotheses are presented to aid future investigations of prenatal exercise and placental health.

Gestational sleep deprivation is associated with higher offspring body mass index and blood pressure

Study Objectives

The objective of this study was to evaluate the association between gestational sleep deprivation and childhood adiposity and cardiometabolic profile.

Methods

Data were used from two population-based birth cohorts (Rhea study and Amsterdam Born Children and their Development study). A total of 3,608 pregnant women and their children were followed up until the age of 11 years. Gestational sleep deprivation was defined as 6 or fewer hours of sleep per day, reported by questionnaire. The primary outcomes included repeated measures of body mass index (BMI), waist circumference, body fat, serum lipids, systolic and diastolic blood pressure (DBP) levels in childhood. We performed a pooled analysis with adjusted linear mixed effect and Cox proportional hazards models. We tested for mediation by birthweight, gestational age, and gestational diabetes.

Results

Gestational sleep deprivation was associated with higher BMI (beta; 95% CI: 0.7; 0.4, 1.0 kg/m²) and waist circumference (beta; 95% CI: 0.9; 0.1, 1.6 cm) in childhood, and increased risk for overweight or obesity (HR; 95% CI: 1.4; 1.1, 2.0). Gestational sleep deprivation was also associated with higher offspring DBP (beta; 95% CI: 1.6; 0.5, 2.7 mmHg). The observed associations were modified by sex (all p-values for interaction < 0.05); and were more pronounced in girls. Gestational diabetes and shorter gestational age partly mediated the seen associations.

Conclusions

This is the first study showing that gestational sleep deprivation may increase offspring’s adiposity and blood pressure, while exploring possible mechanisms. Attention to glucose metabolism and preterm birth might be extra warranted in mothers with gestational sleep deprivation.

Physical Activity in Pregnancy: Beliefs, Benefits, and Information-Seeking Practices of Pregnant Women in South Africa

Background

Notwithstanding the benefits of physical activity (PA) during pregnancy, anecdotal evidence suggests ignorance, unscientific beliefs, and lack of awareness about PA among pregnant South African women.

Aim

This study examined the beliefs, perceived benefits, and sources of information on PA during pregnancy.

Methods

A cross-sectional descriptive study was employed between June and September 2019 using an interviewer-administered questionnaire with 1,082 pregnant women. These women were attending antenatal primary health–care clinics in Buffalo City, Eastern Cape, South Africa. A self-designed questionnaire solicited information on beliefs, benefits, and sources of information regarding PA during pregnancy.

Results

A majority of the participants held positive beliefs concerning PA during pregnancy. They maintained that PA was safe for mother and fetus, improved labor and delivery (93.1%), promoted energy (89.0%), and should be discontinued when tired (76.6%). Most held negative convictions that PA during pregnancy increased body temperature (64.5%) and that pregnancy was a time to rest and refrain from PA (56.5%). Predominantl sources of information received about PA during pregnancy were television, the radio, and other media (70.2%). Most participants were aware of the benefits of PA during pregnancy —— reduction in infant weight (61.4%), lessening of moodiness (90.4), and decreased risk of gestational diabetes mellitus (92.9%), pregnancy-induced hypertension (92.5%), and complications at birth (97.8%), while common negative perceptions included musculoskeletal discomfort (82.7%), and back pain (85.7%). An overwhelming majority affirmed that PA improved self-image (95.7%), sleep patterns (94.2%), and respiratory function (95.8%).

Conclusion

Our findings suggested that women hold positive beliefs and perceive PA as beneficial to their health and the baby; however, they received most of their information from the Internet. Most women regarded pregnancy as a period to relax and rest. Interventions to promote PA during pregnancy are needed.

Physical Activity Behaviors and Barriers in Multifetal Pregnancy: What to Expect When You're Expecting More

The health benefits of prenatal physical activity (PA) are established for singleton pregnancies. In contrast, individuals with multifetal pregnancies (twins, triplets or more) are recommended to restrict or cease PA. The objectives of the current study were to determine behaviors and barriers to PA in multifetal pregnancies. Between 29 May and 24 July 2020, individuals with multifetal pregnancies participated in an online survey. Of the 415 respondents, there were 366 (88%) twin, 45 (11%) triplet and 4 (1%) quadruplet pregnancies. Twenty-seven percent (n = 104/388) of respondents completed no PA at all during pregnancy, 57% (n = 220/388) completed PA below current recommendations, and 16% (n = 64/388) achieved current recommendations (150-min per week of moderate-intensity activity). Most respondents (n = 314/363 [87%]) perceived barriers to PA during multifetal pregnancy. The most prominent were physical symptoms (n = 204/363 [56%]) and concerns about risks to fetal wellbeing (n = 128/363 [35%]). Sixty percent (n = 92/153) felt that these barriers could be overcome but expressed the need for evidence-based information regarding PA in multifetal pregnancy. Individuals with multifetal pregnancies have low engagement with current PA recommendations but remain physically active in some capacity. There are physical and psychosocial barriers to PA in multifetal pregnancy and future research should focus on how these can be removed.

The Effect of Maternal Physical Activity and Gestational Weight Gain on Placental Efficiency

INTRODUCTION

Adherence to physical activity (PA) and gestational weight gain (GWG) recommendations during pregnancy has been shown to improve maternal and fetal health outcomes, including reducing the risk for chronic diseases. Limited research has evaluated the effect of meeting PA in combination with GWG recommendations on placental efficiency (Pl-E), a surrogate marker of the placenta's ability to exchange nutrients and gas based on surface area. The purpose of this study was to measure and compare Pl-E based on meeting PA and GWG recommendations.

METHOD

Healthy pregnant women (n = 61) wore accelerometers in their second and third trimesters to objectively measure PA. Women were classified as active or inactive at each time point based on meeting the 2019 Canadian prenatal PA guidelines. Total GWG was calculated as weight measured in the third trimester minus self-reported prepregnancy weight, and were categorized as insufficient (n = 19), adequate (n = 22), and excessive (n = 20) according to the 2009 Institute of Medicine guidelines. Placental weight (PW) and birth weight (BW) were measured within 30 min of delivery and 24-48 h postdelivery, respectively. Pl-E was determined in three ways: BW:PW ratio, residual BW, and measured BW, with a higher value indicating better Pl-E. Pl-E was compared by PA and GWG status using a two-way ANOVA.

RESULTS

No differences were found in the BW:PW ratio or residual BW corresponding to PA and GWG status. Measured BW was significantly higher in newborns of women who gained weight excessively compared with those who gained insufficient weight (P < 0.05).

CONCLUSION

These findings suggest that prenatal PA does not compromise Pl-E; however, further research is required to evaluate the potential mechanistic benefits of meeting PA and GWG guidelines on the placenta.

Reducing intergenerational obesity and diabetes risk

To address the intergenerational transmission of obesity and diabetes, strategies promoting the health of women of reproductive age appear to be urgently needed. In this narrative review, we summarise what has been learned from many prenatal clinical trials, discuss the emerging evidence from preconception clinical trials and highlight persistent gaps and critical future directions. Most trials tested prenatal interventions that resulted in a limited gestational weight gain of ~1 kg and reduced gestational diabetes by 20-30%. These interventions also reduced macrosomia by 20-40% but had little-to-no impact on other offspring outcomes at birth or beyond. Far fewer trials tested preconception interventions, with almost all designed to improve conception or live-birth rates in overweight or obese women with infertility rather than reduce intergenerational risks in diverse populations. Preconception trials have successfully reduced weight by 3-9 kg and improved markers of glucose homeostasis and insulin resistance by the end of the intervention but whether effects were sustained to conception is unclear. Very few studies have reported offspring outcomes at birth and beyond, with no evidence thus far of beneficial effects on offspring obesity or diabetes risks. Further efforts to develop effective and scalable strategies to reduce risk of obesity and diabetes before conception should be prioritised, especially for diverse and under-resourced populations at disparately high risk of obesity and diabetes. Future clinical trials should include interventions with high potential for dissemination, diverse populations, thorough maternal phenotyping from enrolment through to conception and pregnancy, and rigorous assessment of offspring obesity and diabetes risks from birth onwards, including into the third generation.

Associations between lifestyle interventions during pregnancy and childhood weight and growth: a systematic review and meta-analysis

BACKGROUND

Maternal health and lifestyle during pregnancy may be critical for the onset and progression of childhood obesity. Prenatal lifestyle interventions have been shown to positively affect maternal behaviors, gestational weight gain, and anthropometric outcomes in infants at birth. The influence of such interventions on child weight or growth beyond birth is unknown. We therefore examined the association between lifestyle interventions during pregnancy and anthropometric outcomes during childhood.

METHODS

A systematic literature search was conducted in three electronic databases, two clinical trial registers and further sources, without language or publication status restrictions. Additionally, 110 study authors were contacted to obtain unpublished data. Randomized controlled trials comparing any antenatal lifestyle or behavioral intervention to standard prenatal care, in women of any body mass index (BMI), with offspring anthropometric data at 1 month of age or older, were considered. Two reviewers independently extracted data and assessed the risk of bias using the Cochrane Collaboration's updated tool. Data on weight, length, and BMI, and corresponding z-scores, were stratified into six age ranges and weighted mean differences (WMD) with 95% confidence intervals (CI) were calculated in univariate and multivariate random-effects meta-analytical models.

RESULTS

Twenty trials comprising 11,385 women were included in this systematic review, of which 19 were combined in meta-analyses. Overall, lifestyle interventions during pregnancy were not associated with differences in weight, length, BMI, or corresponding z-scores, in children aged 1 month to 7 years (e.g. weight in 5 to 6 month old children, WMD: 0.02 kg; 95% CI: - 0.05 to 0.10 kg, I2 = 38%; 13 studies, 6667 participants). Findings remained consistent when studies were stratified by maternal baseline BMI or other risk factors, and intervention content and duration. Based on the GRADE criteria, the strength of the body of evidence was considered moderate.

CONCLUSION

Prenatal lifestyle interventions were not shown to influence childhood weight or growth. Nevertheless, women should be encouraged to pursue a healthy lifestyle during pregnancy. Further efforts to establish early prevention strategies for childhood obesity are urgently needed. Thus, large, high-quality studies with pre-planned, long-term follow-ups are warranted.

TRIAL REGISTRATION

PROSPERO CRD42018118678 .

The impact of maternal protein restriction during perinatal life on the response to a septic insult in adult rats

Although abundant evidence exists that adverse events during pregnancy lead to chronic conditions, there is limited information on the impact of acute insults such as sepsis. This study tested the hypothesis that impaired fetal development leads to altered organ responses to a septic insult in both male and female adult offspring. Fetal growth restricted (FGR) rats were generated using a maternal protein-restricted diet. Male and female FGR and control diet rats were housed until 150-160 d of age when they were exposed either a saline (control) or a fecal slurry intraperitoneal (Sepsis) injection. After 6 h, livers and lungs were analyzed for inflammation and, additionally, the amounts and function of pulmonary surfactant were measured. The results showed increases in the steady-state mRNA levels of inflammatory cytokines in the liver in response to the septic insult in both males and females; these responses were not different between FGR and control diet groups. In the lungs, cytokines were not detectable in any of the experimental groups. A significant decrease in the relative amount of surfactant was observed in male FGR offspring, but this was not observed in control males or in female animals. Overall, it is concluded that FGR induced by maternal protein restriction does not impact liver and lung inflammatory response to sepsis in either male or female adult rats. An altered septic response in male FGR offspring with respect to surfactant may imply a contribution to lung dysfunction.

Treadmill Running of Mouse as a Model for Studying Influence of Maternal Exercise on Offspring

Epidemiological studies robustly show the beneficial effects of maternal exercise in reducing maternal birth complications and improving neonatal outcomes, though underlying mechanisms remain poorly understood. To facilitate mechanistic exploration, a protocol for maternal exercise of mice is established, with the regimen following the exercise guidelines for pregnant women. Compared to volunteer wheel running, treadmill running allows precise control of exercise intensity and duration, dramatically reducing variations among individual mouse within treatments and facilitating translation into maternal exercise in humans. Based on the maximal oxygen consumption rate (VO₂max) before pregnancy, the treadmill exercise protocol is separated into three stages: early stage (E1.5 to E7.5 at 40% VO₂max), mid stage (E8.5 to E14.5 at 65% VO₂max), and late stage of pregnancy (E15.5 to birth at 50% VO₂max), which demonstrated persistent beneficial effects on maternal health and fetal development. This protocol can be useful for standardizing maternal treadmill exercise using mice as an experimental model.

Maternal Inactivity Programs Skeletal Muscle Dysfunction in Offspring Mice by Attenuating Apelin Signaling and Mitochondrial Biogenesis

Although maternal exercise (ME) becomes increasingly uncommon, the effects of ME on offspring muscle metabolic health remain largely undefined. Maternal mice are subject to daily exercise during pregnancy, which enhances mitochondrial biogenesis during fetal muscle development; this is correlated with higher mitochondrial content and oxidative muscle fibers in offspring muscle and improved endurance capacity. Apelin, an exerkine, is elevated due to ME, and maternal apelin administration mirrors the effect of ME on mitochondrial biogenesis in fetal muscle. Importantly, both ME and apelin induce DNA demethylation of the peroxisome proliferator-activated receptor γ coactivator-1α (Ppargc1a) promoter and enhance its expression and mitochondrial biogenesis in fetal muscle. Such changes in DNA methylation were maintained in offspring, with ME offspring muscle expressing higher levels of PGC-1α1/4 isoforms, explaining improved muscle function. In summary, ME enhances DNA demethylation of the Ppargc1a promoter in fetal muscle, which has positive programming effects on the exercise endurance capacity and protects offspring muscle against metabolic dysfunction.

Son et al. demonstrate that maternal exercise facilitates fetal muscle development, which improves muscle function and exercise endurance in offspring. Maternal administration of apelin, an exerkine, mirrors the beneficial effects of maternal exercise on mitochondrial biogenesis and fetal muscle development. These findings suggest apelin and its receptor as potential drug targets for improving fetal muscle development of sedentary mothers.

Prenatal Counseling throughout Pregnancy: Effects on Physical Activity Level, Perceived Barriers, and Perinatal Health Outcomes: A Quasi-Experimental Study

Physical activity during pregnancy has many health benefits. However, the physical activity level is insufficient throughout pregnancy and women report perceived barriers to physical activity. This study assessed the impact of a counseling intervention offered in addition to routine pregnancy care on physical activity patterns, perceived barriers, and perinatal health outcomes. A quasi-experimental trial was conducted in the Maternity Unit of a hospital in Guadeloupe (a French department). Ninety-six pregnant women were allocated to a control or intervention group. Regular physical activity counseling was dispensed to the women in the intervention group by trained healthcare providers. The physical activity level and the perceived barriers were assessed in each trimester. Outcomes for the perinatal health of the mother and child were measured throughout pregnancy and after delivery. The perceived barriers, such as a lack of information about the health benefits and risks over the two trimesters (all p < 0.05) and insecurity related to practice throughout pregnancy (all p < 0.05), were different in favor of the intervention group. There were no significant between-group differences for the major indices of physical activity, whether measured or reported. The intervention women reported significantly more sedentary activity compared with the control group in the third trimester, 64.7 (36.4–78.7) vs. 22.7 (9.4–49.8) MET-hours/week, respectively (p < 0.001). The perinatal health outcomes for the mother and child showed no significant differences. The intervention was unable to limit the decline in physical activity or improve health outcomes. However, it was associated with an improvement in the perception of barriers. Future research should focus on interventions that have a sufficient quantitative impact on perceived barriers in order to limit physical activity decline.

Physical activity and exercise during pregnancy in Africa: a review of the literature

BACKGROUND

Pregnancy is an important phase in a woman's life, with health status at this stage affecting both the woman and her child's life. Global evidence suggests that many women engage in low levels of physical activity (PA) and exercise during pregnancy despite its beneficial effects. This is particularly the case in Africa.

METHODS

This article reviews the literature on levels of PA and exercise among pregnant women in Africa, highlighting the level of PA or exercise participation during pregnancy in Africa, including types of PA, factors affecting PA, beliefs about and benefits of prenatal activity, advice or counselling on PA during pregnancy in Africa, and PA interventions proposed to promote the uptake of prenatal PA. Electronic search databases used were Google Scholar, Science Direct, Scopus, EMBASE, ERIC, Medline, Web of Science, EBSCOhost, PubMed, BIOMED Central, and African Journal Online. The basic search terms were: 'Physical activity', 'Exercise', 'Pregnancy', 'Pregnant women' and 'Africa'. A total of 40 references were found. On the basis of an analysis of titles, abstracts and the language of publication (other than English), 11 articles were rejected, and 29 articles were fully read, although two had to be rejected due to a lack of access to the full version. Finally, 27 references were included in the review.

RESULTS

Few studies exist on PA during pregnancy in Africa. The limited data available suggests that, compared to the Western world, pregnant women in Africa do not adhere to the recommendations for PA during pregnancy. Levels of participation in PA during pregnancy are low and decline as the pregnancy progresses. The majority of the studies used direct, objective measures to assess PA during pregnancy. Personal and environmental factors such as lack of time, lack of knowledge, inadequate information from healthcare providers, feelings of tiredness and an absence of social support constituted the main barriers to PA during pregnancy. The types of PA participation among pregnant women varied across studies and geographical settings.

CONCLUSIONS

While published data is limited, it seems clear that the participation of pregnant women in PA during pregnancy in Africa is low and declines with advancing pregnancy. There is a need for more studies to examine the dynamics of PA during pregnancy in Africa to guide contextual interventions to improve and promote maternal health on the continent.

Prenatal Exercise and Cardiorespiratory Health and Fitness: A Meta-analysis

PURPOSE

This study aimed to examine the influence of prenatal exercise on maternal cardiorespiratory health and fitness during pregnancy.

METHODS

Online databases were searched up to February 25, 2019. Studies of randomized controlled trials (RCTs) were eligible, which contained information on the relevant population (pregnant women), intervention (subjective or objective measures of frequency, intensity, duration, volume, or type of exercise), comparator (no exercise intervention), and outcomes (maternal cardiorespiratory fitness, including V˙O2max, submaximal V˙O2, V˙O2 at anaerobic threshold, and cardiorespiratory health, including resting heart rate, and resting systolic and diastolic blood pressures during pregnancy).

RESULTS

From 2699 unique citations, 26 RCTs (N = 2292 women) were included. Of these, one study reported measured V˙O2max, seven reported predicted V˙O2max, three reported submaximal V˙O2, and two studies reported VO2AT. "Low"- to "high"-certainty evidence revealed that exercise was associated with improved predicted/measured V˙O2max (5 RCTs, n = 430; mean difference [MD], 2.77 mL·kg·min; 95% confidence interval [CI], 0.32 to 5.21 mL·kg·min; I = 69%), reduced resting heart rate (9 RCTs, n = 637; MD, -1.71 bpm; 95% CI, -3.24 to -0.19 bpm; I = 13%), resting systolic blood pressure (16 RCTs, n = 1672; MD, -2.11 mm Hg; 95% CI, -3.71 to -0.51 mm Hg; I = 69%), and diastolic blood pressure (15 RCTs, n = 1624; MD, -1.77 mm Hg; 95% CI, -2.90 to -0.64 mm Hg; I = 60%).

CONCLUSION

Prenatal exercise interventions improve maternal predicted/measured V˙O2max and reduce resting heart rate and blood pressure. This review highlights the need for additional high-quality studies of cardiorespiratory fitness (namely, V˙O2max and V˙O2 peak) in pregnancy.PROSPERO registration number: CRD42019131249.

Maternal exercise conveys protection against NAFLD in the offspring via hepatic metabolic programming

Maternal exercise (ME) during pregnancy has been shown to improve metabolic health in offspring and confers protection against the development of non-alcoholic fatty liver disease (NAFLD). However, its underlying mechanism are still poorly understood, and it remains unclear whether protective effects on hepatic metabolism are already seen in the offspring early life. This study aimed at determining the effects of ME during pregnancy on offspring body composition and development of NAFLD while focusing on proteomic-based analysis of the hepatic energy metabolism during developmental organ programming in early life. Under an obesogenic high-fat diet (HFD), male offspring of exercised C57BL/6J-mouse dams were protected from body weight gain and NAFLD in adulthood (postnatal day (P) 112). This was associated with a significant activation of hepatic AMP-activated protein kinase (AMPK), peroxisome proliferator-activated receptor alpha (PPARα) and PPAR coactivator-1 alpha (PGC1α) signaling with reduced hepatic lipogenesis and increased hepatic β-oxidation at organ programming peak in early life (P21). Concomitant proteomic analysis revealed a characteristic hepatic expression pattern in offspring as a result of ME with the most prominent impact on Cholesterol 7 alpha-hydroxylase (CYP7A1). Thus, ME may offer protection against offspring HFD-induced NAFLD by shaping hepatic proteomics signature and metabolism in early life. The results highlight the potential of exercise during pregnancy for preventing the early origins of NAFLD.

Developing a Physical Activity Intervention Strategy for Pregnant Women in Buffalo City Municipality, South Africa: A Study Protocol

Despite global awareness about the importance and health benefits of physical activity (PA) during pregnancy, several studies have reported a low prevalence of PA participation among pregnant women in both developed and developing countries. This means that most pregnant women do not meet the current PA recommended guideline of 150 min of moderate intensity PA per week. The global call to prioritise PA participation levels in the general population necessitates evaluating the factors affecting PA practice. Seemingly, pregnant women mostly from low-to-middle income countries like South Africa are often predisposed to adverse pregnancy outcomes, possibly because of limited access to, and knowledge of, improved pregnancy and health outcomes as a result of PA participation. Physical activity has been sparsely studied among pregnant South African women, and specifically, there is no known study that assesses the PA levels, patterns, beliefs, sources of information, perceived benefits, barriers, attitudes of pregnant women concerning PA and exercise participation; nor one that explores the perspectives of healthcare providers regarding prenatal PA in the Eastern Cape Province. In addition, no PA intervention strategy exists to promote PA participation in the region. This study, in attempting to fill these gaps in knowledge, adopts two phases. In Phase I, a concurrent mixed-method (quantitative and qualitative) approach assesses the following factors related to PA participation in pregnant women: participation levels, beliefs, attitudes, perceived benefits, barriers to uptake and sources of information. It further ascertains if healthcare professionals are sufficiently informed about PA and if they are advising pregnant women about the need for PA participation during pregnancy. Data will be collected through a structured questionnaire, interviews and focus group discussions. Information on socio-demographic and maternal characteristics will be obtained, and the Pregnancy Physical Activity Questionnaire (PPAQ) will assess PA during pregnancy. A sample size of 384 pregnant women is the required minimum sample for an infinite population at a confidence level of 95%, a precision level of ± 5% and at a prevalence of PA or exercise during pregnancy of 50% (p < 0.05); however, a sample size larger than the minimum number necessary will be recruited to account for possible attrition and to protect against possible data loss. Data will be analysed using a multiple logistic regression to determine the factors that predict sedentary or moderate PA levels and chi-squared analysis to determine the associations between the PA levels of the participants and socio-demographic and clinical variables. The study will assess the data collected on the above-mentioned variables and draw conclusions based on patterns and themes that emerge during analysis. Phase II of the study focuses on strategy development and validation to facilitate the promotion of PA during pregnancy. The developed strategy will be validated through the application of the Delphi technique and the administration of a checklist to selected key stakeholders through organised workshops. Understanding the level and correlates of PA participation among this special population is fundamental to designing intervention strategies to enhance their understanding of, and participation in, PA and exercise. Furthermore, this study's findings will inform facility-based healthcare providers about the need to integrate health education on PA and pregnancy into antenatal and postnatal care visits in the setting.

Knowledge translation and social media: Twitter data analysis of the 2019 Canadian Guideline for Physical Activity throughout Pregnancy

OBJECTIVES

Despite extensive evidence demonstrating the benefits of prenatal physical activity (PA), inefficient knowledge translation may contribute to low rates of PA during pregnancy. This study aimed to examine the impact of the 2019 Canadian Guideline for Physical Activity throughout Pregnancy (hereafter Guideline) on knowledge transmission via Twitter.

METHODS

Tweets containing keywords regarding prenatal PA were mined using the Twitter Application Programming Interface 1 month prior to (PRE), and 2 months following (POST-Month1 and Month2) Guideline release (October 18, 2018). The volume, user and location of Tweets relevant to prenatal PA were analyzed.

RESULTS

In this 3-month period, 19,944 Tweets were collected. After randomization to select 10% of the sample, 1995 Tweets were analyzed. Tweets related to prenatal PA increased following Guideline release (PRE = 318/674 [45%]; POST-Month1 = 377/755 [50%]); however, this was not sustained into POST-Month2 (202/566 [36%]). The main users Tweeting about prenatal PA were categorized as 'General Population' (33%), whereas top users Tweeting about the Guideline were 'Academics' (25%), 'Exercise Specialists' (27%) and 'Medical Professionals' (20%). POST-Guideline, Tweets originated from users in 42 countries (PRE = 28).

CONCLUSIONS

Twitter can be an effective tool for knowledge transmission of PA guidelines to a variety of end-users around the globe.

Adaptation of an exercise intervention for pregnant women to community-based delivery: a study protocol

INTRODUCTION

Despite well-established guidelines and benefits to exercise, the majority of pregnant women in the USA fail to meet recommended activity levels. Studies need to determine feasible ways to translate clinical interventions to community settings by engaging pregnant women in widely accessible locations to ensure benefits to more women. The aim of this study is to adapt and determine feasibility, acceptability and fidelity of the research clinic-based Expecting intervention (NCT02125149) with pregnant women with obesity in community settings.

METHODS AND ANALYSIS

We will use the Replicating Effective Programs (REP) to guide the adaptation and implementation of the research clinic-based intervention into the community. REP provides a four-phase process for implementing evidence-based interventions including collection of feedback from community stakeholders, iterative piloting of the intervention in the community and a process for standardising the intervention across community settings. Following adaptation, the updated intervention will be piloted. The pilot study will include 60 expecting women. We will randomise half to receive the community-adapted Expecting intervention (intervention, N=30) and half to receive standard of care (control, N=30). Feasibility and Acceptability of Intervention Measures are primary outcomes as key indicators of feasibility. Secondary outcomes will include the number of intervention sessions completed, the change in the number of minutes of physical activity as measured by accelerometer, as well as change in health indicators from enrolment to time of delivery and 6 months post-delivery (ie, body mass index, blood pressure and total cholesterol).

ETHICS AND DISSEMINATION

This study has been approved by the Institutional Review Board (#260132). Findings will be shared with study participants and stakeholder advisors through written summaries and in-person presentations; results will also be shared through presentations at scientific conferences and publications in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT04298125; Pre-results.

Association between change in maternal physical activity during pregnancy and infant size, in a sample overweight or obese women

Physical activity (PA) naturally declines during pregnancy and its effects on infant size are unclear, especially in overweight or obese pregnancies, a low-active subpopulation that tends deliver heavier infants. The objective of this study was to evaluate changes in prenatal PA and infant birthweight in a group of overweight or obese pregnant women. We employed a prospective analysis using data from a randomized controlled exercise trial (2001 to 2006) in sedentary, overweight or obese pregnant women in Michigan. Women with complete data on peak oxygen consumption, daily PA (via pedometers) and birthweight were included in the analyses. Change in PA was estimated via repeated measures analyses, and then its influence on infant birthweight was assessed via linear regression. Eighty-nine pregnant women were included and considered low-active (6,579.91 ± 2379.17 steps/day). PA declined from months 4 to 8 (-399.73 ± 371.38 steps∙day-1∙month-1). Analyses showed that the decline in PA (β = -0.28 g, 95%CI: -0.70, 0.25 g, p = .35) was not associated with birthweight. The findings of this study demonstrated that the decline in maternal PA during mid- to late-pregnancy, in overweight or obese women, was unrelated to infant birthweight. Future investigations should employ rigorous measurements of PA and infant anthropometry in this subpopulation.

Maternal physical activity significantly alters the placental transcriptome

INTRODUCTION

Maternal lifestyle, in particular physical activity (PA), influences many of the physiological adaptations during pregnancy associated with feto-placental development and growth. There is limited to no information on the link between PA during pregnancy and the molecular mechanisms governing placental function. The aim of this study was to investigate the molecular mechanisms through which maternal PA may influence placental function.

METHODS

The level of PA was measured by accelerometry and gene expression was measured in term placenta with custom polymerase chain reaction (PCR) arrays and microarray analysis followed by a pathway analyses on significantly differentially expressed genes (DEGs).

RESULTS

Microarray analysis showed 43 significantly DEGs between active and non-active participants. RT-qPCR validation of a sub-sample of DEGs revealed significant changes in the level of expression between active and non-active moms (student's t-test, p < 0.05, n = 11). Genes involved in transport of water (p = 0.00236) and uptake of glycerol (p = 0.00219) were enriched in active moms. PA was also associated with the alteration of alternative splicing patters. The most consistent splicing changes were observed for AQP9 where active moms lacked exon 2.

DISCUSSION

Variations in maternal PA influences placental gene. We show significant expression changes of genes that are involved in transport and localization between active and non-active women. Most notably, the expression of the aquaporin family of genes (e.g. AQP1 and AQP9) were found to be significantly higher in the placentas of active women suggesting an adaptive response for the transport of water and glycerol in this population.

Be Healthy in Pregnancy: Exploring factors that impact pregnant women's nutrition and exercise behaviours

Excess gestational weight gain is associated with short‐ and long‐term pregnancy complications. Although a healthy diet and physical activity during pregnancy are recommended and shown to reduce the risk of complications and improve outcomes, adherence to these recommendations is low. The aims of this study were to explore women's view of nutrition and physical activity during pregnancy and to describe barriers and facilitators experienced in implementing physical activity and nutrition recommendations. In a substudy of the Be Healthy in Pregnancy randomized trial, 20 semistructured focus groups were conducted with 66 women randomized to the control group when they were between 16 and 24 weeks gestation. Focus groups were recorded, transcribed verbatim, coded and thematically analysed. The results indicate that women felt motivated to be healthy for their baby, but competing priorities may take precedence. Participants described limited knowledge and access to information on safe physical activity in pregnancy and lacked the skills needed to operationalize both physical activity and dietary recommendations. Women's behaviours regarding diet and physical activity in pregnancy were highly influenced by their own and their peers' beliefs and values regarding how weight gain impacted their health during pregnancy. Pregnancy symptoms beyond women's control such as fatigue and nausea made physical activity and healthy eating more challenging. Counselling from care providers about nutrition and physical activity was perceived as minimal and ineffective. Future interventions should address improving counselling strategies and address individual's beliefs around nutrition and activity in pregnancy.

Testing the Multiple Pathways of Residential Greenness to Pregnancy Outcomes Model in a Sample of Pregnant Women in the Metropolitan Area of Donostia-San Sebastián

Residential greenness may positively impact diverse human health indicators through the reduction of air pollution, the improvement of psychological health, and the promotion of physical activity. Previous studies indicate a weak but positive association with pregnancy outcomes. Our aim was to test the multiple pathways from residential greenness to pregnancy outcomes model, using residential NO₂ concentrations, psychological health, and moderate-to-vigorous physical activity (MVPA) during the first trimester of pregnancy, in a sample of 440 pregnant women residing in Donostia, Spain. Three metrics of residential greenness were calculated around each participant’s home address: normalized difference vegetation index (NDVI) within 300 m, and green space (>5000 m²) availability within 300 and 500 m. Residential NO₂ concentrations, psychological health, and MVPA were explored as mediators of the associations between these metrics and the following pregnancy outcomes: birth weight (BW), low birth weight (LBW), prematurity, small for gestational age (SGA), and large for gestational age (LGA). Educational attainment, parity, and body mass index (BMI) were treated as covariates. Counterfactual mediation analyses showed very low to null statistical support for an association between any of the greenspace metrics and pregnancy outcomes in the full sample. Green space availability (300 m) was associated with lower BW and showed a marginal protective effect against LGA.

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.

The Effect of Exercise Training During Pregnancy to Improve Maternal Vascular Health: Focus on Gestational Hypertensive Disorders

Hypertensive disorders of pregnancy, including gestational hypertension and pre-eclampsia, occur in up to 10% of pregnancies and are associated with increased life-long cardiovascular risk. Physical activity improves cardiovascular health in pregnancy and may lower the risk of developing hypertensive disorders of pregnancy. However, a minority of pregnant women comply with the recommended level of physical activity. Adequate knowledge on the physiological effects of exercise in healthy pregnancy could help to overcome potential barriers as pregnancy is a unique window of opportunity to improve health outcomes for both mother and child. In this mini review, we discuss structural and functional vascular adaptations during healthy and hypertensive pregnancies, we elaborate on the effects of exercise on the vasculature and review the safety and existing evidence of exercise training as preventive therapy for gestational hypertensive disorders.