Assessment of physical fitness during pregnancy: validity and reliability of fitness tests, and relationship with maternal and neonatal health - a systematic review.

Objectives: To systematically review studies evaluating one or more components of physical fitness (PF) in pregnant women, to answer two research questions: (1) What tests have been employed to assess PF in pregnant women? and (2) What is the validity and reliability of these tests and their relationship with maternal and neonatal health? Design: A systematic review. Data sources: PubMed and Web of Science. Eligibility criteria: Original English or Spanish full-text articles in a group of healthy pregnant women which at least one component of PF was assessed (field based or laboratory tests). Results: A total of 149 articles containing a sum of 191 fitness tests were included. Among the 191 fitness tests, 99 (ie, 52%) assessed cardiorespiratory fitness through 75 different protocols, 28 (15%) assessed muscular fitness through 16 different protocols, 14 (7%) assessed flexibility through 13 different protocols, 45 (24%) assessed balance through 40 different protocols, 2 assessed speed with the same protocol and 3 were multidimensional tests using one protocol. A total of 19 articles with 23 tests (13%) assessed either validity (n=4), reliability (n=6) or the relationship of PF with maternal and neonatal health (n=16). Conclusion: Physical fitness has been assessed through a wide variety of protocols, mostly lacking validity and reliability data, and no consensus exists on the most suitable fitness tests to be performed during pregnancy. PROSPERO registration number: CRD42018117554.

The Influence of Exercise, Lifestyle Behavior Components, and Physical Fitness on Maternal Weight Gain, Postpartum Weight Retention, and Excessive Gestational Weight Gain.

This study examines (a) the influence of exercise, lifestyle behavior components (sedentary time, physical activity, and sleep and dietary patterns), and physical fitness on maternal weight gain, postpartum weight retention, and excessive gestational weight gain and (b) whether exercise protects against the adverse effects of impaired metabolism and nonoptimal body composition related to excessive gestational weight gain. Subjects were assigned to either a supervised concurrent (aerobic + resistance) exercise program followed 3 days/week (n = 47) or a control group (n = 54). Sedentary time, physical activity, sleep and dietary patterns (assessed by accelerometry and questionnaires), muscle strength (handgrip test), and cardiorespiratory fitness (Bruce test) were determined at gestational Weeks 16 and 33 (early-middle and late pregnancy, respectively), and at 6 weeks postpartum. Weight gain and weight retention were calculated using recorded weights at prepregnancy, early-middle, and late pregnancy, and at 6 weeks postpartum. Birth complications, maternal postpartum body composition, cardiometabolic, and inflammatory markers in maternal and umbilical cord arterial and venous blood, and in colostrum, and mature milk were also recorded. The exercise intervention reduced late weight gain (B = -2.7, SE = 0.83, p = .003) and weight retention (B = -2.85, SE = 1.3, p = .03), independent of any lifestyle behavior component or physical fitness, but did not prevent excessive weight gain. Increasing cardiorespiratory fitness, muscle strength, and sleep duration were associated with a smaller mean weight gain and lower excessive weight gain values (p < .05). Among the participants who experienced excessive weight gain, those who were exercisers had a lower body mass index and systemic tumor necrosis factor-alpha concentration, lower umbilical cord venous tumor necrosis factor-alpha and arterial interferon gamma levels, higher cord arterial interleukin-10 levels, and improved placental function compared with controls (p < .05). In summary, exercise may help optimize gestational weight gain and weight retention, and may attenuate the impaired phenotype related to excessive weight gain. Increasing cardiorespiratory fitness, muscle strength, and sleep duration might help to prevent excessive weight gain during pregnancy.

Association of Self-Reported Physical Fitness during Late Pregnancy with Birth Outcomes and Oxytocin Administration during Labour-The GESTAFIT Project.

We explored (a) the associations between self-reported maternal physical fitness and birth outcomes; (b) whether self-reported maternal physical fitness (PF) is related to the administration of oxytocin to induce or stimulate labour. Pregnant women from the GESTAFIT project randomized controlled trial (n = 117) participated in this prospective longitudinal study. Maternal physical fitness was assessed through the International Fitness Scale at the 34th gestational week. Maternal and neonatal birth outcomes and oxytocin administration were collected from the obstetric medical records. Umbilical arterial and venous cord blood gas were analysed immediately after birth. Self-reported overall fitness, cardiorespiratory fitness, muscular strength and flexibility were not related to any maternal and neonatal birth outcomes (all p > 0.05). Greater speed-agility was associated with a more alkaline arterial (p = 0.04) and venous (p = 0.02) pH in the umbilical cord blood. Women who were administered oxytocin to induce or stimulate labour reported lower cardiorespiratory fitness (p = 0.013, Cohen's d = 0.55; 95% confidence interval (CI): 0.14, 0.93) and flexibility (p = 0.040, Cohen´s d = 0.51; 95% CI: 0.09, 0.89) compared to women who were not administered oxytocin. Greater maternal physical fitness during pregnancy could be associated with better neonatal birth outcomes and lower risk of needing oxytocin administration.

Associations of physical activity, sedentary time, and physical fitness with mental health during pregnancy: The GESTAFIT project.

PURPOSE: This study was aimed to analyze the associations of objectively measured physical activity (PA), sedentary time, and physical fitness with mental health in the early second trimester (16 ± 2 gestational weeks) of pregnancy. METHODS: From 229 women initially contacted, 124 pregnant women participated in the present cross-sectional study. Data were collected between November 2015 and March 2017. The participants wore Actigraph GT3X+ Triaxial accelerometers for 9 consecutive days to objectively measure their PA levels and sedentary time. A performance-based test battery was used to measure physical fitness. Self-report questionnaires assessed psychological ill-being (i.e., negative affect, anxiety, and depression), and psychological well-being (i.e., emotional intelligence, resilience, and positive affect). Linear regression analyses were adjusted for age, educational level, accelerometer wear time, miscarriages, and low back pain. RESULTS: Moderate-to-vigorous PA was negatively associated with depression (ß = -0.222, adjusted R2 = 0.050, p = 0.041). Higher levels of sedentary time were negatively associated with positive affect (ß = -0.260, adjusted R2 = 0.085, p = 0.017). Greater upper-body flexibility was positively associated with better emotional regulation (ß = 0.195, adjusted R2= 0.030, p = 0.047). The remaining associations were not significant (all p > 0.05). CONCLUSION: An active lifestyle characterized by higher levels of moderate-to-vigorous PA and lower levels of sedentary time during pregnancy might modestly improve the mental health of pregnant women. Although previous research has focused on the benefits of cardiorespiratory exercise, the present study shows that only upper-body flexibility is related to emotional regulation in early pregnant women. If the present findings are corroborated in further experimental research, physical exercise programs should focus on enhancing flexibility to promote improvements in emotional regulation during early second-trimester of pregnancy.

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.

Correction: Association of objectively measured physical fitness during pregnancy with maternal and neonatal outcomes. The GESTAFIT Project.

[This corrects the article DOI: 10.1371/journal.pone.0229079.].

Association of objectively measured physical fitness during pregnancy with maternal and neonatal outcomes. The GESTAFIT Project.

AIM: To analyse i) the association of physical fitness during early second trimester and late pregnancy with maternal and neonatal outcomes; and ii) to investigate whether physical fitness is associated with the type of birth (vaginal or caesarean section). METHODS: Pregnant women from the GESTAFIT Project (n = 159) participated in this longitudinal study. Maternal physical fitness including upper- and lower-body strength, cardiorespiratory fitness (CRF) and flexibility were measured through objective physical fitness tests at the 16th and 34th gestational weeks. Maternal and neonatal outcomes were collected from obstetric medical records. Umbilical arterial and venous blood gas pH and partial pressure of carbon dioxide (PCO2) and oxygen (PO2), were assessed. RESULTS: At the 16th week, greater upper-body muscle strength was associated with greater neonatal birth weight (r = 0.191, p<0.05). Maternal flexibility was associated with a more alkaline arterial pH (r = 0.220, p<0.05), higher arterial PO2 (r = 0.237, p<0.05) and lower arterial PCO2 (r = -0.331, p<0.01) in umbilical cord blood. Maternal CRF at the 16th gestational week was related to higher arterial umbilical cord PO2 (r = 0.267, p<0.05). The women who had caesarean sections had lower CRF (p<0.001) at the 16th gestational week and worse clustered overall physical fitness, both at the 16th (-0.227, p = 0.003, confidence interval (CI): -0.376, -0.078) and 34th gestational week (-0.223; p = 0.018; CI: -0.432, -0.015) compared with the women who had vaginal births. CONCLUSION: Increasing physical fitness during pregnancy may promote better neonatal outcomes and is associated with a decrease in the risk of caesarean section. This trial was registered at ClinicalTrials.gov (NCT02582567) on October 20, 2015.

International Fitness Scale-IFIS: Validity and association with health-related quality of life in pregnant women.

This study aimed (a) to examine the construct validity of the International Fitness Scale (IFIS) to discriminate between different objectively measured physical fitness levels in pregnant women and (b) to assess the extent to which IFIS is able to discriminate between pregnant women with different levels of health-related quality of life (HRQoL). A total of 159 pregnant women were involved in the GESTAtion and FITness project: 106 pregnant women (mean age 32.7, SD 4.4 years) were included. Self-reported physical fitness-that is, cardiorespiratory fitness, muscular strength, flexibility, and overall fitness-was assessed with the IFIS. Physical fitness was objectively measured using the Bruce test, the handgrip strength test and the back-scratch test. The HRQoL was assessed with the 36-item Short Form Health Survey (SF-36). Higher self-reported physical fitness measured with IFIS was associated with higher objectively measured physical fitness (P < .05). There was a linear association so that higher self-reported physical fitness (ie, IFIS; regardless of the fitness component) was related to greater General Health dimension scores (P < .05). Moreover, higher self-reported physical fitness (all components except muscular strength) was associated with better Physical Functioning, lower Bodily Pain and higher Vitality scores (ie, SF-36 components). This linear trend was not seen for objectively measured physical fitness. The results of this study suggest that IFIS might be a useful tool for identifying pregnant women with low or very low physical fitness and with low quality of life health-related. Further research should elucidate whether IFIS can identify women with pregnancy complications before it can be implemented in clinical practice.

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

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

Association of self-reported physical fitness with pain during pregnancy: The GESTAFIT Project.

AIMS: To explore the association of self-reported physical fitness with bodily, lumbar and sciatic pain, and pain disability during pregnancy. METHODS: The present study sample comprised 159 pregnant women (32.9 ± 4.7 years old). Self-reported physical fitness was assessed with the International Fitness Scale (IFIS), where higher scores indicate greater physical fitness. Bodily pain was assessed with the 36-Item Short Form Health Survey (SF-36), where higher scores indicate lower pain. Lumbar and sciatic pain were measured with a visual analogue scale (VAS). The Oswestry Disability Index (ODI) questionnaire was employed to assess the disability resulting from pain. Measures were assessed at 16th and 34th gestational weeks (g. w.). RESULTS: Pregnant women showed low-moderate pain during pregnancy course. Most of them showed medium self-reported overall physical fitness. At 16th g. w., greater self-reported overall physical fitness and cardiorespiratory fitness were associated with less bodily and lumbar pain, and pain disability (all, P < 0.05). Greater muscular strength was associated with less bodily pain and pain disability (both, P < 0.05). Greater speed-agility was associated with less bodily pain (P < 0.01) and less pain disability (P < 0.05). Self-reported flexibility was not associated with any outcome (P > 0.05). At 34th g. w., greater overall physical fitness and its components were associated with less bodily and sciatic pain (all, P < 0.05). CONCLUSION: Greater self-reported overall physical fitness and its components are associated with less bodily, lumbar and sciatic pain, and reduced pain disability during pregnancy. Future studies are needed to explore whether increasing physical fitness before and during pregnancy could decrease pain in this relevant stage.

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.

Influence of a Concurrent Exercise Training Program During Pregnancy on Colostrum and Mature Human Milk Inflammatory Markers: Findings From the GESTAFIT Project.

BACKGROUND: Although exercise reduces systemic inflammation, information regarding its influence on human milk is scarce or inexistent. Research Aim: The aim of this study was to investigate the influence of an exercise intervention during pregnancy on colostrum and mature human milk inflammatory markers. METHODS: The authors conducted a pseudorandomized controlled trial. The exercise group followed a concurrent aerobic and strength training, three 60-minutes sessions per week, from the 17th gestational week until delivery. For the specific aims of this study, only women able to produce enough milk were included for data analyses, resulting in 24 exercise and 23 control women. Colostrum and mature human milk proinflammatory and anti-inflammatory cytokines (fractalkine, interleukin [IL]-1ß, IL-6, IL-8, IL-10, interferon [IFN]-γ, and tumor necrosis factor [TNF]-α) were measured using Luminex xMAP technology. RESULTS: The mothers who followed the exercise program had 36% lower IL-8 and 27% lower TNF-α concentrations in their colostrum than those in the control group ( p < .05 and p < .01, respectively). The colostrum from mothers who followed the exercise program also presented borderline significant 22% lower IL-6 ( p < .100). The mature milk from mothers who followed the exercise program had 30% greater fractalkine ( p = .05) and borderline significant 20% higher IL-10 ( p = .100). The exercise intervention did not affect IFN-γ concentrations. CONCLUSIONS: This concurrent exercise program promoted a less proinflammatory profile in human milk, especially in colostrum. Moreover, it might increase mature human milk fractalkine, which could induce a greater neurodevelopment and neuroprotection in the newborn. This trial was registered at ClinicalTrials.gov (NCT02582567) on October 20, 2015.

Effects of supervised aerobic and strength training in overweight and grade I obese pregnant women on maternal and foetal health markers: the GESTAFIT randomized controlled trial.

BACKGROUND: During pregnancy, a sedentary lifestyle may have negative consequences on maternal and foetal health status. The main objective of this project is to assess the effects of an exercise intervention in overweight and grade I obese pregnant on maternal and foetal health markers. METHODS/DESIGN: The present study aims to recruit 60 overweight and grade I obese women interested in participating in an exercise intervention program from the 17th gestational week until delivery. Women will be randomized to either an exercise (three 60-min sessions/week of combined aerobic and strength training and pelvic floor exercises), or usual care (control) group (30 women per group). The primary outcome measures are maternal weight gain, and maternal and neonatal glycaemic profile. Secondary outcome measures are: i) perinatal obstetric records; i) body composition; iii) dietary patterns; iv) physical fitness; v) low-back pain; vi) objectively measured physical activity and sedentary behaviour; vii) haematology and biochemical analyses; viii) oxidative stress; ix) pro- and anti-inflammatory markers; x) bone health biomarkers; xi) sleep quality; xii) mental health, quality of life and positive health. DISCUSSION: The findings of this project will help to identify strategies for primary prevention and health promotion based on this exercise-based intervention program among overweight and grade I obese pregnant women. TRIAL REGISTRATION: NCT02582567 ; Date of registration: 20/10/2015.