Influence of maternal physical activity on infant's body composition

Physical activity during pregnancy and adverse birth outcome: a prospective cohort study in China

Objectives The relationship between prenatal physical activity (PA) and adverse birth outcomes is still inconclusive. We aimed to investigate the association between PA during pregnancy and adverse birth outcomes by using data from the Guangxi Zhuang birth cohort (GZBC) in China.Study Design A total of 11,292 mother-infant pairs were included from GZBC in China. The information on PA status, intensity, adequacy, and volume and birth outcomes were collected. Multivariable linear and logistic regression models were applied to analyze the effects of PA during pregnancy on birth weight z-scores (BW z-scores) and gestational age and risk of small-for-gestational age (SGA) and preterm birth (PTB), respectively. Cubic spline analysis was conducted to detect a nonlinear dose-response of total weekly activity metabolic equivalents (MET) and birth outcomes.Results Compared to no regular PA during pregnancy, moderate and high-intensity PA (MVPA) was associated with increase BW z-scores (β = 0.08, 95%CI: 0.002, 0.15, p = .044) and associated with a marginal significant decrease in risk of PTB (OR = 0.73, 95%CI: 0.51, 1.05, p = .093). However, PA had no relationship with gestational age and risk of SGA, and Nonlinear relationships were not observed between total weekly activity MET and risk of SGA and PTB.Conclusion These finding shows that PA during pregnancy may increase the BW z-score and reduce risk of PTB, supporting the guidelines that pregnant women should be encouraged to engage in appropriate physical activity during pregnancy in China.

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

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

A narrative review of exercise dose during pregnancy

The current recommendations for prenatal exercise dose align with those from the American College of Sports Medicine; 150 min of moderate intensity every week of pregnancy. However, recent works suggest there may be a dose-dependent beneficial effect for mother and offspring; maternal and offspring health outcomes respond differently to low, medium, and high doses of prenatal exercise. It is, therefore, our aim to summarize the published evidence (years 1950-2023) for five metrics of prenatal exercise training commonly reported, that is, "FITT-V": Frequency (number of sessions), Intensity (metabolic equivalents "METs"), Time (duration of sessions), Type (exercise mode), Volume (exercise MET*mins). The target audience includes clinicians and health care professionals, as well as exercise professionals and physiologists. Data suggest that moderate exercise frequency (3-4 times weekly) appears safe and efficacious for mother and offspring, while there is contradictory evidence for the safety and further benefit of increased frequency beyond 5 sessions per week. Moderate (3-6 METs) and vigorous (>6 METs) intensity prenatal exercise have been shown to promote maternal and offspring health, while little research has been performed on low-intensity (<3 METs) exercise. Exercise sessions lasting less than 1 hr are safe for mother and fetus, while longer-duration exercise should be carefully considered and monitored. Taken together, aerobic, resistance, or a combination of exercise types is well tolerated at medium-to-high volumes and offers a variety of type-specific benefits. Still, research is needed to define (1) the "minimum" effective dose of exercise for mother and offspring health, as well as (2) the maximum tolerable dose from which more benefits may be seen. Additionally, there is a lack of randomized controlled trials addressing exercise doses during the three trimesters of pregnancy. Further, the protocols adopted in research studies should be more standardized and tested for efficacy in different populations of gravid women.

Maternal Aerobic Exercise, but Not Blood Docosahexaenoic Acid and Eicosapentaenoic Acid Concentrations, during Pregnancy Influence Infant Body Composition

Although discrete maternal exercise and polyunsaturated fatty acid (PUFA) supplementation individually are beneficial for infant body composition, the effects of exercise and PUFA during pregnancy on infant body composition have not been studied. This study evaluated the body composition of infants born to women participating in a randomized control exercise intervention study. Participants were randomized to aerobic exercise (n = 25) or control (stretching and breathing) groups (n = 10). From 16 weeks of gestation until delivery, the groups met 3×/week. At 16 and 36 weeks of gestation, maternal blood was collected and analyzed for Docosahexaenoic Acid (DHA) and Eicosapentaenoic Acid (EPA). At 1 month postnatal, infant body composition was assessed via skinfolds (SFs) and circumferences. Data from 35 pregnant women and infants were analyzed via t-tests, correlations, and regression. In a per protocol analysis, infants born to aerobic exercisers exhibited lower SF thicknesses of triceps (p = 0.008), subscapular (p = 0.04), SF sum (p = 0.01), and body fat (BF) percentage (%) (p = 0.006) compared with controls. After controlling for 36-week DHA and EPA levels, exercise dose was determined to be a negative predictor for infant skinfolds of triceps (p = 0.001, r2 = 0.27), subscapular (p = 0.008, r2 = 0.19), SF sum (p = 0.001, r2 = 0.28), mid-upper arm circumference (p = 0.049, r2 = 0.11), and BF% (p = 0.001, r2 = 0.32). There were no significant findings for PUFAs and infant measures: during pregnancy, exercise dose, but not blood DHA or EPA levels, reduces infant adiposity.

Physical Activity during Pregnancy and Newborn Body Composition: A Systematic Review

The current literature demonstrates that not only is exercise during pregnancy safe, but it has substantial maternal and infant benefits and appears to influence infant growth/size throughout pregnancy and at birth. However, many existing studies have investigated only the effects of prenatal exercise on birth weight. The purpose of this review was to determine the impact or association of maternal physical activity during pregnancy on neonatal body composition assessed between birth and two weeks of age. Electronic database searches were conducted on 29 July 2019 for randomized control trials and cohort studies, with an updated search completed on 8 January 2021. A total of 32 articles that met eligibility criteria were selected for review. Overall, prenatal exercise was not associated with infant body composition at birth. Yet, five of the studies identified suggest that infant body composition could be influenced by higher volumes of mid-to-late term prenatal physical activity. This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and registered in PROSPERO (Registration No. CRD42020160138).

Objectively measured sedentary time and physical activity levels in Spanish pregnant women. Factors affecting the compliance with physical activity guidelines

The aims of this cross-sectional study were to describe objectively measured sedentary time (ST) and physical activity (PA) levels in Spanish pregnant women, to analyze the degree of compliance with PA guidelines during the early second trimester of pregnancy and to explore sociodemographic and clinical factors associated with meeting these PA guidelines. One hundred and thirty-four Caucasian pregnant women were recruited between October 2015 and October 2017 to participate in this study. Triaxial accelerometers were used to analyze ST andPA levels for seven consecutive valid days. Womenspent512 ± 92.1 minutes daily in sedentary behaviors, and 85 ± 108.2 minutes in moderate-to-vigorous physical activity (MVPA) in bouts of at least 10 minutes. They walked on average 7436 ± 2410steps per day. Only 22% of the study sample complied with the PA guidelines. Having an University degree was related with threefold higher odds of compliance with the PA guidelines (95% confidence interval: 0.096-0.913, p < .05). Binary logistic regressions showed that being primiparous was associated with fivefold higher odds of compliance with the PA guidelines (95% confidence interval 1.658-18.039, respectively, p < .01). Maternal age, BMI, marital status, working status, and previous miscarriages were not associated with compliance with PA guidelines. Pregnant women spent more than a third of the day in sedentary behaviors and the compliance with PA guidelines was less than desirable. Finally, not having an university degree or having children could be factors related to lower odds of compliance with these guidelines, and therefore require special attention from healthcare professionals.

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.

Physical fitness is associated with prostaglandin F2α isomers during pregnancy

INTRODUCTION

Pregnancy and physical activity are associated with oxidative stress and immune changes. We hypothesized that pregnant women physically more active in early pregnancy will display a better oxidative stress management and inflammatory response later in pregnancy compared with less active pregnant women.

MATERIAL AND METHODS

Maternal physical activity using accelerometry monitors for 1 week and cardiorespiratory fitness (VO₂ at anaerobic threshold) were assessed at 14-18 weeks in 58 pregnant women. Plasma and erythrocytes membrane samples were obtained from maternal blood samples at 14-18 and 34-37 weeks of pregnancy. Pro-inflammatory prostaglandin (PG) F_2α and oxidative stress-derived F₂-isoprostanes were measured by high-performance liquid chromatography coupled to tandem mass spectrometry.

RESULTS

Higher physical activity levels at 14-18 weeks measured by mean counts per minute, >30 min/d of moderate to vigorous activity or >6500 steps/d at 14-18 weeks of pregnancy were associated with lower levels of total plasmatic PGF_2α later in pregnancy. Concentrations of 5 F₂-isomers in erythrocyte membranes in late pregnancy were significantly higher in the third (17.5-19.5 mL kg^-1 min^-1) and/or fourth (19.6-27.7 mL kg^-1 min^-1) quartiles of cardio-respiratory fitness compared to the first quartile (13.9-15.9 mL kg^-1 min^-1).

CONCLUSIONS

Overall, higher cardio-respiratory fitness in early pregnancy is associated with enhanced erythrocyte membranes oxidation at 34-37 weeks reflecting a higher oxygen transfer capacity. Also, the most active women experienced lower circulating levels of pro-inflammatory PGF_2α in plasma at 34-37 weeks, a marker associated with adverse antenatal inflammation-associated conditions. These results support the practice of physical activity by pregnant women.

A reduction in sedentary behaviour in obese women during pregnancy reduces neonatal adiposity: the DALI randomised controlled trial

AIMS/HYPOTHESIS

Offspring of obese women are at increased risk of features of the metabolic syndrome, including obesity and diabetes. Lifestyle intervention in pregnancy might reduce adverse effects of maternal obesity on neonatal adiposity.

METHODS

In the Vitamin D And Lifestyle Intervention for Gestational Diabetes Mellitus (GDM) Prevention (DALI) lifestyle trial, 436 women with a BMI ≥29 kg/m² were randomly assigned to counselling on healthy eating (HE), physical activity (PA) or HE&PA, or to usual care (UC). In secondary analyses of the lifestyle trial, intervention effects on neonatal outcomes (head, abdominal, arm and leg circumferences and skinfold thicknesses, estimated fat mass, fat percentage, fat-free mass and cord blood leptin) were assessed using multilevel regression analyses. Mediation of intervention effects by lifestyle and gestational weight gain was assessed.

RESULTS

Outcomes were available from 334 neonates. A reduction in sum of skinfolds (-1.8 mm; 95% CI -3.5, -0.2; p = 0.03), fat mass (-63 g; 95% CI -124, -2; p = 0.04), fat percentage (-1.2%; 95% CI -2.4%, -0.04%; p = 0.04) and leptin (-3.80 μg/l; 95% CI -7.15, -0.45; p = 0.03) was found in the HE&PA group, and reduced leptin in female neonates in the PA group (-5.79 μg/l; 95% CI -11.43, -0.14; p = 0.05) compared with UC. Reduced sedentary time, but not gestational weight gain, mediated intervention effects on leptin in both the HE&PA and PA groups.

CONCLUSIONS/INTERPRETATION

The HE&PA intervention resulted in reduced adiposity in neonates. Reduced sedentary time seemed to drive the intervention effect on cord blood leptin. Implications for future adiposity and diabetes risk of the offspring need to be elucidated.

TRIAL REGISTRATION

ISRCTN70595832.

Maternal exercise before and during gestation modifies liver and muscle mitochondria in rat offspring

It is now well established that the intrauterine environment is of major importance for offspring health during later life. Endurance training during pregnancy is associated with positive metabolic adjustments and beneficial effects on the balance between pro-oxidants and antioxidants (redox state) in the offspring. Our hypothesis was that these changes could rely on mitochondrial adaptations in the offspring due to modifications of the fetal environment induced by maternal endurance training. Therefore, we compared the liver and skeletal muscle mitochondrial function and the redox status of young rats whose mothers underwent moderate endurance training (treadmill running) before and during gestation (T) with those of young rats from untrained mothers (C). Our results show a significant reduction in the spontaneous H₂O₂ release by liver and muscle mitochondria in the T versus C offspring (P<0.05). These changes were accompanied by alterations in oxygen consumption. Moreover, the percentage of short-chain fatty acids increased significantly in liver mitochondria from T offspring. This may lead to improvements in the fluidity and the flexibility of the membrane. In plasma, glutathione peroxidase activity and protein oxidation were significantly higher in T offspring than in C offspring (P<0.05). Such changes in plasma could represent an adaptive signal transmitted from mothers to their offspring. We thus demonstrated for the first time, to our knowledge, that it is possible to act on bioenergetic function including alterations of mitochondrial function in offspring by modifying maternal physical activity before and during pregnancy. These changes could be crucial for the future health of the offspring.

Structured diet and exercise guidance in pregnancy to improve health in women and their offspring: study protocol for the Be Healthy in Pregnancy (BHIP) randomized controlled trial

BACKGROUND

Evidence from epidemiological and animal studies support the concept of programming fetal, neonatal, and adult health in response to in utero exposures such as maternal obesity and lifestyle variables. Excess gestational weight gain (GWG), maternal physical activity, and sub-optimal and excess nutrition during pregnancy may program the offspring's risk of obesity. Maternal intake of dairy foods rich in high-quality proteins, calcium, and vitamin D may influence later bone health status. Current clinical practice guidelines for managing GWG are not founded on randomized trials and lack specific "active intervention ingredients." The Be Healthy in Pregnancy (BHIP) study is a randomized controlled trial (RCT) designed to test the effectiveness of a novel structured and monitored Nutrition + Exercise intervention in pregnant women of all pre-pregnancy weight categories (except extreme obesity), delivered through prenatal care in community settings (rather than in hospital settings), on the likelihood of women achieving recommended GWG and a benefit to bone status of offspring and mother at birth and six months postpartum.

METHODS

The BHIP study is a two-site RCT that will recruit up to 242 participants aged > 18 years at 12-17 weeks of gestation. After baseline measures, participants are randomized to either a structured and monitored Nutrition + Exercise (intervention) or usual care (control) program for the duration of their pregnancy. The primary outcome of the study is the percent of women who achieve GWG within the Institute of Medicine (IOM) guidelines. The secondary outcomes include: (1) maternal bone status via blood bone biomarkers during pregnancy; (2) infant bone status in cord blood; (3) mother and infant bone status measured by dual-energy absorptiometry scanning (DXA scan) at six months postpartum; (4) other measures including maternal blood pressure, blood glucose and lipid profiles, % body fat, and postpartum weight retention; and (5) infant weight z-scores and fat mass at six months of age.

DISCUSSION

If effective, this RCT will generate high-quality evidence to refine the nutrition guidelines during pregnancy to improve the likelihood of women achieving recommended GWG. It will also demonstrate the importance of early nutrition on bone health in the offspring.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01689961 Registered on 21 September 2012.

Association of sedentary time and physical activity during pregnancy with maternal and neonatal birth outcomes. The GESTAFIT Project

AIM

(a) To analyse the association of objectively measured sedentary time (ST) and physical activity (PA) during early second trimester of pregnancy with maternal and neonatal birth outcomes; (b) to explore if ST and PA differ between women with vaginal or caesarean section deliveries.

METHODS

Ninety-four Caucasian pregnant women (32.9 ± 4.6 years old) participated in this prospective longitudinal study. Triaxial accelerometers were used to assess ST and PA intensity levels for seven consecutive days during second trimester of pregnancy. Birth data were collected from the obstetric medical records. Umbilical cord arterial and venous blood gas (pH, partial pressure of carbon dioxide and oxygen, and oxygen saturation) were analysed after birth.

RESULTS

After adjusting for potential confounders, greater ST was associated with higher arterial and venous cord blood partial pressure of carbon dioxide and more acidic arterial and venous pH (all, P < 0.01). Moderate PA, moderate-to-vigorous PA (MVPA), total PA and steps per day were positively associated with arterial cord blood oxygen saturation (all P < 0.05). Steps per day were inversely associated with gestational age at birth (P < 0.01), and duration of first stage of labor (P < 0.05). Total and light PA were associated with a more alkaline pH in umbilical vein (all, P < 0.01). Vigorous PA was inversely associated with the Apgar score (P < 0.01). No significant differences were observed in ST and PA levels between women with vaginal and women with caesarean section deliveries (all, P > 0.10).

CONCLUSION

Increasing PA and decreasing ST during pregnancy might promote better maternal and neonatal birth markers.

Associations between maternal physical activity and fitness during pregnancy and infant birthweight

Prenatal physical activity (PA) reduces the risk of delivering infants with a birthweight ≥4000 g among normal-weight pregnant women, but evidence on the impact of maternal cardiorespiratory fitness (CRF) on birthweight remains equivocal among overweight or obese (OW/OB) pregnant women. The purpose of this study was to evaluate the relationship between maternal prenatal PA and CRF and birthweight in OW/OB pregnant women. Data from a randomized controlled exercise intervention trial in sedentary, OW/OB pregnant women were used. Women with complete data (n = 89) on birthweight, peak oxygen consumption (at 17 weeks), and daily PA were selected for analyses. Multiple linear regression models were performed to determine the independent and joint associations of maternal PA and CRF with birthweight while adjusting for gestational age, weight gain, and group allocation. On average, participants were 32 years old, OW/OB (BMI 29.97 ± 7.14 kg/m2), unfit (VO2peak: 19.85 ± 3.35 ml O2 kg-1 min-1), and led low active lifestyles (6579.91 ± 2379.17 steps/day). Analyses showed that maternal PA (steps·day-1·month-1) (β = 0.03 g, 95% CI: -0.03, 0.08 g) and CRF (ml O2·kg-1·min-1) (β = -8.8 g, 95%CI: -42.2, 24.5 g) were neither independently nor jointly (β = 0.006 g, 95%CI: -0.005, 0.02 g) associated with birthweight. Maternal PA and CRF during pregnancy were not related to birthweight in OW/OB pregnant women. The limited variability in maternal PA and CRF and low dose of PA may explain the null findings of this study. Given the paucity of studies examining these relationships in OW/OB pregnant women, more research is warranted.

Exercise as a therapeutic intervention to optimize fetal weight

The Developmental Origins of Health and Disease suggest the in utero environment programs offspring obesity and cardiovascular disease. Therefore, there is a need to implement safe therapeutic interventions that do not involve the intake of medications or biological products during pregnancy that can improve maternal and fetal health. Prenatal exercise is established to promote maternal and fetal health. It is generally recommended that women accumulate at least 150 min per week of moderate-intensity exercise. It has been demonstrated that prenatal exercise maintains healthy weight gain and improves maternal glucose control, maternal cardiac autonomic control, placental efficiency (increases angiogenesis, downregulates genes involved in fatty acid transport and insulin transport across the placenta, and upregulates genes involved in amino acid transport across the placenta), and oxidative stress. These adaptations following exercise improve maternal metabolism and provide adequate uteroplacental perfusion. In this review, we will focus on exercise as a therapeutic intervention to optimize fetal weight. It has been established that prenatal exercise does not increase the risk of having a small for gestational age baby. To the contrary, prenatal exercise has been associated with the prevention of excessive fat accumulation in the newborn and the maintenance of fetal muscle mass.

Sexual Dimorphism and the Origins of Human Spinal Health

Recent observations indicate that the cross-sectional area (CSA) of vertebral bodies is on average 10% smaller in healthy newborn girls than in newborn boys, a striking difference that increases during infancy and puberty and is greatest by the time of sexual and skeletal maturity. The smaller CSA of female vertebrae is associated with greater spinal flexibility and could represent the human adaptation to fetal load in bipedal posture. Unfortunately, it also imparts a mechanical disadvantage that increases stress within the vertebrae for all physical activities. This review summarizes the potential endocrine, genetic, and environmental determinants of vertebral cross-sectional growth and current knowledge of the association between the small female vertebrae and greater risk for a broad array of spinal conditions across the lifespan.

Associations of Maternal Light/Moderate Leisure-Time Walking and Yoga With Offspring Birth Size

BACKGROUND

Although perinatal walking and yoga have been associated with decreased risks of pregnancy complications, associations with offspring birth size have been inconsistent. We investigated associations of prepregnancy and early pregnancy leisure-time light/moderate walking and yoga practice with birth size.

METHODS

Study participants (N = 3687) reported leisure-time physical activity duration (hours per week) in the year before pregnancy and early pregnancy. Birth size was abstracted from medical records. Regression was used to determine mean differences in birth weight, head circumference, and ponderal index. Interaction terms were used to assess effect modification by offspring sex.

RESULTS

About one-third of women reported light/moderate leisure-time walking and about 10% reported yoga practice. Women in the highest tertile for prepregnancy (mean: 2.9 h/wk; range: 1.4-20 h/wk) or early pregnancy (mean: 5.9 h/wk; range: 3.1-24 h/wk) light/moderate walking had offspring with 0.9 and 1.5 kg/m³ greater ponderal index (95% confidence interval, 0.3 to 1.4 and 0.7 to 2.4, respectively) compared with women who reported no light/moderate walking in the same time period. Light/moderate walking was not associated with birth weight or head circumference. Yoga practice was not associated with birth size. Associations were similar by offspring sex.

CONCLUSION

Light/moderate leisure-time walking may be associated with greater offspring ponderal index.

Lifestyle of women before pregnancy and the risk of offspring obesity during childhood through early adulthood

BACKGROUND

In women, adhering to an overall healthy lifestyle is associated with a dramatically reduced risk of cardio-metabolic disorders. Whether such a healthy lifestyle exerts an intergenerational effects on child health deserves examination.

METHODS

We included 5701 children (9-14 years old at baseline) of the Growing Up Today Study 2, and their mothers, who are participants in the Nurses' Health Study II. Pre-pregnancy healthy lifestyle was defined as a normal body mass index, no smoking, physical activity ≥150 min/week, and diet in the top 40% of the Alternative Healthy Eating Index-2010. Obesity during childhood and adolescence was defined using the International Obesity Task Force age- and sex-specific cutoffs. Multivariable log-binominal regression models with generalized estimating equations were used to evaluate the association of pre-pregnancy healthy lifestyle and offspring obesity.

RESULTS

We identified 520 (9.1%) offspring who became obese during follow-up. A healthy body weight of mothers and no smoking before pregnancy was significantly associated with a lower risk of obesity among offspring: the relative risks [RRs; 95% confidence intervals (CIs)] were 0.37 (0.31-0.43) and 0.64 (0.49-0.84), respectively. Eating a healthy diet and regular moderate-to-vigorous physical activities were inversely related to offspring obesity risk, but these relations were not statistically significant. Compared to children of mothers who did not meet any low-risk lifestyle factors, offspring of women who adhered to all four healthy lifestyle factors had 75% lower risk of obesity (RR: 0.25, 95% CI: 0.14-0.43).

CONCLUSION

Adherence to an overall healthy lifestyle before pregnancy is strongly associated with a low risk of offspring obesity in childhood, adolescence, and early adulthood. These findings highlight the importance of an overall healthy lifestyle before pregnancy as a potential strategy to prevent obesity in future generations.

Physical activity during pregnancy and infant's birth weight: results from the 3D Birth Cohort

Aim

To evaluate the association between maternal physical activity and infant’s birth weight or risk of inappropriate weight for gestational age (GA), and whether this association differs by infant’s sex, maternal body mass index (BMI) or pregnancy complications in a prospective cohort study.

Methods

1913 pregnant women from the 3D Birth Cohort (Québec, Canada) completed the Pregnancy Physical Activity Questionnaire at each trimester. Energy expenditure (metabolic equivalent of task (MET)*hours/week) for total activity, sports and exercise and vigorous intensity activities was calculated. The associations with birth weight and risk of inappropriate weight for GA were evaluated by regression modelling. Interactions were tested with infant’s sex, maternal prepregnancy BMI, gestational diabetes, hypertensive disorders and prematurity.

Results

Each 1 MET/hours/week increase in sports and exercise in the first trimester was associated with a 2.5 g reduction in infant’s birth weight (95% CI −4.8 to −0.3) but was not associated with the risk of small weight for GA. In contrast, although not significant, a 17% reduction in the risk of large weight for GA was observed with increasing sports and exercise. Furthermore, in women with subsequent pre-eclampsia (but not normotensive or hypertensive women), each 1 MET/hours/week increment spent in any vigorous exercise in the first trimester reduced the infant’s birth weight by 19.8 g (95% CI −35.2 to −4.3).

Conclusions

Pregnant women with higher sports and exercise levels in the first trimester delivered infants with a lower birth weight. The risk of reducing infant’s birth weight with vigorous exercise in women who develop pre-eclampsia later in pregnancy requires evaluation.

Exercise alters mouse sperm small noncoding RNAs and induces a transgenerational modification of male offspring conditioned fear and anxiety

There is growing evidence that the preconceptual lifestyle and other environmental exposures of a father can significantly alter the physiological and behavioral phenotypes of their children. We and others have shown that paternal preconception stress, regardless of whether the stress was experienced during early-life or adulthood, results in offspring with altered anxiety and depression-related behaviors, attributed to hypothalamic-pituitary-adrenal axis dysregulation. The transgenerational response to paternal preconceptual stress is believed to be mediated by sperm-borne small noncoding RNAs, specifically microRNAs. As physical activity confers physical and mental health benefits for the individual, we used a model of voluntary wheel-running and investigated the transgenerational response to paternal exercise. We found that male offspring of runners had suppressed reinstatement of juvenile fear memory, and reduced anxiety in the light-dark apparatus during adulthood. No changes in these affective behaviors were observed in female offspring. We were surprised to find that running had a limited impact on sperm-borne microRNAs. The levels of three unique microRNAs (miR-19b, miR-455 and miR-133a) were found to be altered in the sperm of runners. In addition, we discovered that the levels of two species of tRNA-derived RNAs (tDRs)-tRNA-Gly and tRNA-Pro-were also altered by running. Taken together, we believe this is the first evidence that paternal exercise is associated with an anxiolytic behavioral phenotype of male offspring and altered levels of small noncoding RNAs in sperm. These small noncoding RNAs are known to have an impact on post-transcriptional gene regulation and can thus change the developmental trajectory of offspring brains and associated affective behaviors.