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

Exceeding the guidelines: A descriptive study of exercise, pregnancy, maternal and neonatal health outcomes in elite and recreational athletes

BACKGROUND

Exercise during pregnancy is associated with numerous health benefits. However, guidelines for elite and recreational athletes, who often exceed general recommendations regarding intensity, duration, and frequency are lacking, and potential risks remain unclear. The aim of the study was to describe exercise levels, pregnancy, and maternal and neonatal health outcomes in elite and recreational athletes.

METHOD

This study was part of the Strong Mama research project, which was carried out in Oslo, Norway, between October 2022 and February 2024. Sixty athletes (10 elite and 50 recreational) participated in the study. They completed an online survey during late pregnancy and participated in a structured telephone interview six weeks postpartum. The survey and interview collected data on exercise habits, pregnancy experiences, and maternal and neonatal health outcomes.

RESULTS

The athletes maintained high exercise levels during pregnancy, with elite athletes exercising an average of 11.6 h per week (SD 3.2) and recreational athletes exercising 7.0 h per week (SD 2.4). Most athletes resumed exercising within six weeks postpartum. Almost all pregnancies were planned, including six which involved fertility treatment. Most women (76.7%) had spontaneous onset of labor and vaginal deliveries to term (between 36 and 42 weeks). The mean birthweight was 3487 (SD 519.4, range 2600-4775) grams. Two of the elite athletes were diagnosed with gestational diabetes mellitus and two with hypertension during pregnancy. None of the 50 recreational athletes reported any pregnancy complications.

CONCLUSION

High levels of exercise during pregnancy did not seem to negatively impact maternal or neonatal health in this descriptive sample of Norwegian elite and recreational athletes. However, more research is needed to confirm these findings.

Midwives' Knowledge, Attitudes, and Professional Practices Regarding Prenatal Physical Activity

Background/Objectives: Prenatal physical activity (PA) offers numerous health benefits for both the mother and her child, yet few pregnant women are sufficiently active enough to obtain these benefits. Midwives play an important role in promoting prenatal PA. However, little is known about the content of the information they share with their clients regarding prenatal PA, how they communicate it, and the personal factors that might influence their counseling. In the context of prenatal PA guidance, the aim of this study was to describe the knowledge, attitudes, professional practices, and communication methods used by midwives. Methods: A cross-sectional descriptive study was conducted between February and June 2024 among midwives working in the Province of Quebec. An electronic questionnaire including both closed (quantitative data) and open-ended (qualitative data) questions was developed. Results: Fifty midwives were included in the analysis. Only 28 (56%) reported being aware of the latest Canadian guidelines for PA throughout pregnancy. The recommendations provided varied in terms of content and accuracy but were often conservative (i.e., not focused on increasing PA). Forty-five (90%) mentioned providing information on PA to their pregnant client, and eighty-four (84%) said they used bidirectional communication to share this information. The vast majority (84%) did not consider their counseling to be optimal, primarily due to a lack of training and knowledge. Conclusions: Our finding allowed us to gain a better understanding of current midwifery knowledge, attitudes, and professional practices regarding prenatal PA and to initiate a reflection on how to improve their knowledge, skills, and confidence in guiding their client toward prenatal PA.

Effects of exercise on vascular remodelling and fetal growth in uncomplicated and abortion-prone mouse pregnancies

Studies in humans and rodents show exercise in pregnancy can modulate maternal blood pressure, vascular volume, and placental efficiency, but whether exercise affects early uteroplacental vascular adaptations is unknown. To investigate this, CBA/J female mice mated with BALB/c males to generate healthy uncomplicated pregnancies (BALB/c-mated) or mated with DBA/2J males to generate abortion-prone pregnancies (DBA/2J-mated), were subjected to treadmill exercise (5 days/week, 10 m/min, 30 min/day for 6 weeks before and throughout pregnancy), or remained sedentary. In uncomplicated pregnancies, exercise caused symmetric fetal growth restriction in fetuses evidenced by reductions in fetal weight, crown-to-rump length, abdominal girth and biparietal diameter. Placental insufficiency was indicated by reduced fetal: placental weight ratio and increased glycogen cell content in the junctional zone of placentas of exercised BALB/c-mated mice on gestational day (GD)18.5. In abortion-prone pregnancy, exercise increased placental efficiency, but the number of late-pregnancy resorptions were elevated. Effects of paternal genotype independent of exercise were evidenced by a greater number of resorptions, poorer spiral artery remodelling, and larger placentas in the DBA/2J-mated compared to BALB/c-mated mice. Effects of exercise independent of paternal genotype included increased implantation sites at both mid and late pregnancy, accompanied by decreased junctional zone areas of placentas. Our findings show that exercise before and during pregnancy in mice can have different effects on fetal outcomes, depending on the paternal and/or fetal genotype. This suggests that the underlying mechanisms are responsive to fetal cues.

Does antenatal exercise shape labor and delivery outcomes?

PURPOSE

Incorporating regular physical activity into the lifestyle of a pregnant woman offers numerous health benefits and prepares her effectively for labor. This study was conducted to determine the impact of antenatal exercise on labor, delivery and perinatal outcome.

METHODS

An interventional study was conducted including 200 women attending the antenatal clinic of Obstetrics and Gynaecology department of PGIMS Rohtak, India. The study subjects were randomly divided into two groups-exercise group and control group.

RESULTS

The demographic profile of both the groups was similar. A higher proportion of patients in control group required labor induction compared to exercise group (33% vs 16%, P = 0.002). The rate of vaginal delivery was significantly higher in exercise group than in control group (71% vs 56%, P = 0.027). Additionally, women in exercise group had fewer assisted vaginal deliveries than control group (7% vs 20%, P = 0.007). Rates of cesarean section were comparable between both groups (P = 0.736). The mean duration of labor was significantly shorter in exercise group compared to control group (428.69 ± 131.242 min vs 516.91 ± 143.105 min, P < 0.0001). Mean Visual Analog Scale (VAS) score for pain was 6.38 ± 1.94 in exercise group compared to 7.89 ± 1.49 in control group (P < 0.0001). No significant difference was observed between the groups in birth weight and APGAR score of neonates.

CONCLUSION

A structured exercise program, practiced regularly during the antenatal period reduced the need for labor induction, shortened labor duration, increased the incidence of vaginal deliveries, and decreased pain perception during labor and delivery.

Physical activity and associated factors in Australian women during pregnancy: A cross-sectional study

ISSUE ADDRESSED

Whilst the benefits of regular physical activity during pregnancy are well known, the few studies conducted in Australian pregnant women suggest that most do not meet recommended exercise guidelines. The aim of this study was to determine the levels of physical activity, sedentary behaviours, and associated factors in Australian pregnant women.

METHODS

A random sample of pregnant women (N = 780) of (mean [SD]) 31 (5) years of age completed a questionnaire describing weekly physical activity and sedentary behaviours. A number of potential risk factors, including socio-demographic characteristics and ethnicity, were investigated using logistic regression.

RESULTS

Approximately one-third (34%) of women were classified as "active"; however, only 7% of women performed the recommended amount of physical activity according to Australian guidelines. Women reported (mean [95% CI]) sitting for 8 (7.8-8.2) hours and lying down during the day for 0.5 (0.5-0.6) hour while pregnant. Being university educated (OR [95% CI]) (2.87 [1.6-4.9]), in paid employment (2.12 [1.14-3.94]) and having a lower body mass index (0.91 [0.87-0.95]) were factors associated with being active.

CONCLUSION

Australian women performed low levels of physical activity during pregnancy and spend long periods of time in sedentary behaviours. SO WHAT?: There is a strong need for a concerted health promotion strategy to endorse increased physical activity, along with a reduction in sedentary behaviours, during pregnancy to support better maternal outcomes in Australia.

Exercise during pregnancy Dose: Influence on preterm birth outcomes

BACKGROUND

Preterm delivery typically increases health risk for neonates and is associated with longer infant hospital stay and financial burden. Prenatal exercise dose (frequency, intensity, type, time, volume) have been shown to influence birth outcomes. Increased prenatal exercise dose could therefore provide a critical reduction in health risk and financial burden in preterm neonates.

OBJECTIVE

It was our aim to explore the effects of prenatal exercise dose from a supervised exercise intervention in pregnant women on the occurrence of preterm (<37 weeks gestation) births, and the impact on health outcomes in preterm neonates.

STUDY DESIGN

This study is a retrospective, secondary analysis of pooled data from three blinded, prospective, randomized controlled trials. Prenatal exercise dose were assessed in supervised aerobic, resistance, and combination sessions throughout pregnancy. In addition to gestational age, birth weight, resting heart rate, neonatal morphometrics (body circumferences, ponderal index), and health status (Apgar-1 and -5) metrics were obtained for 21 women at birth. One-way analysis of variance tests were used to assess the differences between dose grouped as tertiles, while Pearson correlations determined the association between dose and birth outcomes.

RESULTS

Women exercised for an average of 19.6 wks (range: 6 - 21 wks) during pregnancy. Exercise during pregnancy tended to result in later preterm deliveries (p = 0.08). Greater prenatal exercise volume and duration were associated with reduced infant hospital stay post-delivery (p = 0.02). Weekly exercise volume was associated with increased Apgar scores (p = 0.01).

CONCLUSION

Increased prenatal exercise volume and duration is associated with improved birth outcomes in preterm neonates.

Visiting natural open spaces in urban areas during pregnancy and its association with daily physical activity

We examined the association between visiting natural open spaces (NOS) and physical activity (PA) at different trimesters of pregnancy. We used GPS and accelerometer data from women residing in Donostia-San Sebastian and Barcelona. Daily visits to NOS were associated with an increase of circa 8 min of moderate to vigorous physical activity (MVPA) in the first and second trimesters of pregnancy. Women who visited NOS were more likely to meet the WHO daily PA guidelines during the first trimester. Visiting NOS can promote PA consistently during pregnancy, improving maternal health and well-being in urban settings.

How can the pain sensitivity to be affected by maximal progressive exercise test during pregnancy?

The multidimensional etiology of pain may explain the beneficial effects of regular physical activity, as evidenced by increased pain tolerance. Physically active people find it easier to exert themselves, which enables them to increase their physical activity, which in turn leads to a reduction in pain. However, no study investigated the physical activity and exercise tests as modulators of pain sensitivity in pregnant women. Therefore, this study aimed to investigate the changes in pain perception in pregnant women during pregnancy, with a particular interest in the effects of maximal progressive exercise test (CPET) and self-performed physical activity (PA). Thirty-one women with an uncomplicated singleton pregnancy (aged 23-41 years; M = 31.29, SD = 4.18) were invited to participate in pain sensitivity measurements before and after CPET twice during pregnancy (with an 8-week break). We found that pregnant women had a significantly lower pain threshold after a maximal exercise test than before, regardless of whether the test was performed in the second or third trimester of pregnancy. This effect was most pronounced in women with low levels of physical activity. Second, women with high physical activity had higher pain tolerance than women with moderate and low physical activity. In addition, physical activity levels predicted changes in pain tolerance over the course of pregnancy, with negative changes in women with low physical activity and positive changes in women with moderate physical activity. Finally, these associations were not reflected in differences in the subjective pain experience.

Relationship between first trimester physical activity and premature rupture of membranes: a birth cohort study in Chinese women

OBJECTIVE

This study aimed to examine prospective associations of different intensity levels and types of physical activity (PA) in early pregnancy with premature rupture of membranes (PROM) among Chinese pregnant women.

METHODS

A total of 6284 pregnant women were included from the Tongji-Shuangliu Birth Cohort. Household/caregiving, occupational, sports/exercise and transportation activities during early pregnancy were investigated by the pregnancy physical activity questionnaire (PPAQ), and the diagnosis of PROM was ascertained during the whole pregnancy. Multivariate logistic regression models were used to estimate the odds ratios (ORs) and 95% confidence interval (CI) for the associations between PA and PROM.

RESULTS

Among the 6284 pregnant women, 1246 were identified to have PROM (19.8%). Women undertaking the highest level (3 third tertile) of PA during pregnancy appeared to have a lower risk of PROM [OR = 0.68, 95%CI 0.58-0.80) when compared to those at the lowest tertile of PA. Similarly, women with increased levels of light intensity activity, moderate-vigorous intensive, household/caregiving activity and meeting exercise guidelines during pregnancy were associated with reduced risks of PROM (OR = 0.69, 95% CI 0.59-0.81, OR = 0.70, 95% CI 0.60-0.82, OR = 0.62, 95% CI 0.53-0.73 and OR = 0.82, 95% CI 0.70-0.97, respectively).

CONCLUSIONS

High levels of PA of different intensities and PA of household/caregiving activities and meeting exercise guidelines during the first trimester were associated with a lower incidence of PROM.

TRIAL REGISTRATION

The data of human participants in this study were conducted in accordance with the Helsinki Declaration. This study has been approved by the Ethics Committee of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China ([2017] No. S225). All participants provided written informed consent prior to enrollment. A statement to confirm that all methods were carried out in accordance with relevant guidelines and regulations.

Perception and reality: The mismatch between absolute and relative physical activity intensity during pregnancy and postpartum in United States women

OBJECTIVE

To explore whether a mismatch between absolute physical activity intensity (PAI) and relative self-reported PAI exists during pregnancy and postpartum.

METHODS

Women from the PIN3/Postpartum study completed physical activity questionnaires during pregnancy (n = 770; Trimester 2: T2, Trimester 3: T3) and postpartum (n = 181; 3 months: PP3, 12 months PP12) (2001-2005). Activities women engaged in were assigned Metabolic Equivalent (MET) values for absolute intensity; women self-reported perceived exertion (using the Borg scale) for each activity to provide relative intensity. Hierarchical regression models were used to determine whether a mismatch between absolute and relative PAI (for moderate or vigorous physical activity (MPA; VPA)) differed during pregnancy and postpartum. Models were adjusted for socio-demographic factors.

RESULTS

Women commonly overestimated the amount of MPA and VPA they engaged in [T2 MPA mean 60.5 min/week (49.1, 72.0), VPA 3.7 (-1.4, 8.8); T3: MPA 47.7 (38.9, 56.4), 2.9 (-1.7, 7.4); PP3: MPA 69.5 (43.9, 95.1), VPA 15.8 (1.8, 29.7); PP12: MPA 42.20 (26.8, 57.6), VPA 2.75 (-7.8, 12.9)]. Women overestimated both MPA and VPA to a lesser extent at T3 compared to T2 (MPA: β for difference:-12.6 [95%CI: -26.0, -0.9]; VPA: -0.9 [-6.4, 4.6]). Women continued to overestimate their MPA at PP3 and PP12.

CONCLUSIONS

Compared to absolute PAI, perceived PAI was greater for MPA compared to VPA and differences persisted from pregnancy through postpartum. Future research should focus on how perceptions relate to women's actual physiological capacity and whether this mismatch influences the amount of physical activity women engage in during the transition to motherhood.

Exercise FITT-V during pregnancy: Association with birth outcomes

BACKGROUND

Prenatal exercise improves birth outcomes, but research into exercise dose-response effects is limited.

METHODS

This study is a retrospective, secondary analysis of pooled data from three blinded, prospective, randomized controlled trials. Prenatal exercise frequency, intensity, type, time, and volume (FITT-V) were assessed in supervised sessions throughout pregnancy. Gestational age (GA), neonatal resting heart rate (rHR), morphometrics (body circumferences, weight-to-length and ponderal index) Apgar and reflex scores, and placental measures were obtained at birth. Stepwise regressions and Pearson correlations determined associations between FITT-V and birth outcomes.

RESULTS

Prenatal exercise frequency reduces ponderal index (R2 = 0.15, F = 2.76, p = .05) and increased total number of reflexes present at birth (R2 = 0.24, F = 7.89, p < .001), while exercise intensity was related to greater gestational age and birth length (R2 = 0.08, F = 3.14; R2 = 0.12, F = 3.86, respectively; both p = .04); exercise weekly volume was associated with shorter hospital stay (R2 = 0.24, F = 4.73, p = .01). Furthermore, exercise type was associated with placenta size (R2 = 0.47, F = 3.51, p = .01).

CONCLUSIONS

Prenatal exercise is positively related to birth and placental outcomes in a dose-dependent manner.

Evolution of the human birth canal

It seems puzzling why humans have evolved such a small and rigid birth canal that entails a relatively complex process of labor compared with the birth canal of our closest relatives, the great apes. This study reviewed insights into the evolution of the human birth canal from recent theoretical and empirical studies and discussed connections to obstetrics, gynecology, and orthopedics. Originating from the evolution of bipedality and the large human brain million years ago, the evolution of the human birth canal has been characterized by complex trade-off dynamics among multiple biological, environmental, and sociocultural factors. The long-held notion that a wider pelvis has not evolved because it would be disadvantageous for bipedal locomotion has not yet been empirically verified. However, recent clinical and biomechanical studies suggest that a larger birth canal would compromise pelvic floor stability and increase the risk of incontinence and pelvic organ prolapse. Several mammals have neonates that are equally large or even larger than human neonates compared to the size of the maternal birth canal. In these species, the pubic symphysis opens widely to allow successful delivery. Biomechanical and developmental constraints imposed by bipedality have hindered this evolutionary solution in humans and led to the comparatively rigid pelvic girdle in pregnant women. Mathematical models have shown why the evolutionary compromise to these antagonistic selective factors inevitably involves a certain rate of fetopelvic disproportion. In addition, these models predict that cesarean deliveries have disrupted the evolutionary equilibrium and led to new and ongoing evolutionary changes. Different forms of assisted birth have existed since the stone age and have become an integral part of human reproduction. Paradoxically, by buffering selection, they may also have hindered the evolution of a larger birth canal. Many of the biological, environmental, and sociocultural factors that have influenced the evolution of the human birth canal vary globally and are subject to ongoing transitions. These differences may have contributed to the global variation in the form of the birth canal and the difficulty of labor, and they likely continue to change human reproductive anatomy.

The association between musculoskeletal pain during pregnancy and pregnancy outcomes: A systematic review and meta-analyses

OBJECTIVE

To systematically investigate the association between musculoskeletal pain during pregnancy and birth outcomes including caesarean section, newborn birthweight, newborn birth length, and gestational age at birth.

METHODS

Medline, Embase, Web of Science, Cinahl and Scopus were systematically searched to identify eligible studies. Odds ratios, mean differences, and confidence intervals were used to describe results. Risk of Bias was assessed using the Newcastle-Ottawa Scale for observational studies. GRADE (The Grading of Recommendation Assessment, Development, and Evaluation) was used to assess the quality of each outcome.

RESULTS

Seven studies were included with a total population of 85,991 participants. There is low- quality evidence that pregnant women with musculoskeletal pain had 1.59 greater odds to experience delivery by caesarean section compared to those without musculoskeletal pain ([OR] 1.59, 95 % confidence interval [CI] 1.09 to 2.31). Both newborn birth weight (Mean Difference [MD] 77.79 g, 95 % [CI] -23.09 to 178.67) and newborn birth length ([MD] 0.55 cm, 95 % [CI] -0.47 to 1.56) were not affected by musculoskeletal pain, with very low-quality and low-quality evidence, respectively. There was moderate evidence that pregnant women with musculoskeletal pain had shorter gestational age (weeks), although the effect was small and possibly not clinically relevant ([MD] -0.41, 95 % [CI] -0.41 to -0.07).

CONCLUSION

Pregnant women experiencing musculoskeletal pain are at greater odds of delivering their babies via caesarean than those without musculoskeletal pain, however, musculoskeletal pain during pregnancy does not appear to affect newborn birth weight, length, or gestational age at birth.

Changes in pain perception during pregnancy after one-time maximal physical exertion and an 8-week high-intensity interval training

Background: Pain, a subjective sensation, poses a great challenge to the human body as a stressor. There is empirical evidence that moderate to intense physical activity increases pain tolerance and this may be critical during pregnancy for optimal pregnancy, fetal development, and delivery. To the best of our knowledge, it is the first study examining the changes in pain perception in pregnant women after a maximal progressive exercise test and after 8 weeks of high-intensity interval training (HIIT). Methods: Thirty-five women with uncomplicated singleton pregnancies between 13 and 28 weeks of gestation participated in the study. The HIIT intervention was developed in accordance with the recommendations and available data on HIIT during pregnancy. The maximal progressive cardiopulmonary exercise test was performed on a cycle ergometer with an electronically controlled load. Pressure pain threshold and pressure pain tolerance were measured with an algometer. Results: We found significant effects of the maximal exercise test and high-intensity interval training, such that the pregnant women had higher pain tolerance after the maximal exercise test than before and after the high-intensity interval training than the baseline. Conclusion: Our results suggest that post-exercise analgesia may be important in pregnant women and that high-intensity interval training appears to be beneficial for pregnant women to improve their pain tolerance while being obstetrically safe. Increased pain tolerance before labor could lead to better management of pain during labor and in the postpartum and lactation periods. Increasing pregnant women's awareness of this issue can improve their wellbeing and provide more comfort during labor.

Can Pre-Pregnancy Body Mass Index and Maternal Exercise Affect Birth and Neonatal Outcomes-A Cross Sectional Study

There has been a dramatic worldwide increase in the prevalence of obesity or overweight and physical inactivity in women of reproductive age. Growing evidence suggests that pre-pregnancy maternal abnormal body mass index (BMI) and lower physical activity level are associated with poor maternal health and perinatal outcomes. The aim of this study was to assess how self-perceived exercise and pre-pregnancy BMI are associated with preterm birth, low birth weight, and type of birth. We conducted a retrospective cross-sectional study of 394 Polish women in the postpartum period. We used a questionnaire with the structure of the medical interview. To analyze factors related to birth outcomes, we used the Pearson's Chi-squared test of independence and odds ratio (OR), with a corresponding 95% confidence interval (CI), followed by a multiple logistic regression. Women who reported being physically active before pregnancy (p = 0.00) and during pregnancy (p = 0.03) were more likely to give birth on time and had a lower incidence of very-premature and extremely premature births compared to inactive women. Importantly, they were more likely to have vaginal birth (p = 0.03). Pre-pregnancy BMI influenced the week of delivery, i.e., inadequate, too-high BMI contributed to an increase in the percentage of premature births [OR (95% CI) = 1.19 (1.06; 1.34)]. The findings indicate that promoting physical activity and weight management remains a priority in public health policy, and women of childbearing age should be encouraged to adopt or maintain an active and healthy lifestyle during pregnancy in order to avoid sedentary- and obesity-associated risks affecting birth and newborns' health.

Strategies used by midwives to support prenatal physical activity: A scoping review

CONTEXT

Despite the well-known benefits of prenatal physical activity for the health of both the mother and her future child, and the existence of international Guidelines for prenatal physical activity, few pregnant women are sufficiently active. Prenatal health care providers, notably midwives, play an important role in promoting prenatal physical activity. Unfortunately, they face several challenges that hinder strategies used to support prenatal physical activity to their clients. The mode of communication used when giving advice and counselling is part of these strategies, as is the content of the information provided. However, little is known about how midwives communicate with their clients when it comes to recommendations about prenatal physical activity, whether it is general or specific recommendations, and about personal factors that may influence their recommendations.

OBJECTIVE

To present a comprehensive analysis of the existing literature on strategies used by midwives to support prenatal physical activity to their clients, focusing on the mode of communication used, the content of the recommendation provided, as well as personal factors that can influence their recommendations.

METHOD

A scoping review was conducted to retrieve original research articles on strategies used by midwives to support prenatal physical activity, published up to May 2023 and available in English and French. The search databases included CINAHL, MEDLINE, Cochrane, Scopus, PubMed, Psychology and behavioural Sciences Collection, and APA PsycINFO. Studies that fulfilled the eligibility criteria were selected for data extraction. The main findings were organized by the mode of communication used (unidirectional and bidirectional) and the type of recommendation provided (general versus specific). Midwives' knowledge, beliefs and attitudes towards prenatal physical activity were also extracted.

RESULTS

A total of 1 307 articles were retrieved and 19 were included. The use of unidirectional mode of communication was identified in 64 %, 64 % and 14 % of the studies when it comes to provide general recommendations, specific recommendations and information on safety, respectively. The use of bidirectional mode of communication was identified in 43 %, 21 % and 7 % of the studies when it comes to provide general recommendations, specific recommendations and information on safety, respectively. Midwives had knowledge gaps about prenatal physical activity, their beliefs were not always aligned with the most recent recommendations, and they sometimes feel vulnerable in the way they support physical activity. However, they expressed the desire to improve the support they are providing.

CONCLUSION

Results of this study highlight that when it comes to support prenatal physical activity, the unidirectional mode of communication is the most often used by midwives. Unfortunately, it is not considered effective as it does not allow discussing and explaining the information provided. Moreover, midwives exhibited some knowledge gaps about prenatal physical activity. Future work will be needed to better understand their challenges and needs in order to improve their initial training and clinical practice.

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.

[Sedentary lifestyle in pregnancy: Effects on the mother and the newborn]

OBJECTIVE

Identify the state of sedentary lifestyle during pregnancy and the factors associated with this behavior, the possible factors of your health situation and that of the newborn.

MATERIAL AND METHODS

This two-phase, cross-sectional observational study was developed at the La Fe University and Polytechnic Hospital and 228 pregnant women participated. Maternal sociodemographic characteristics were obtained using structured questionnaire and health information from the electronic medical records, as well as perinatal results of the newborn. To assess sedentary lifestyle, exercise in free time and exercise during working hours were assessed, categorizing them based on intensity (sedentary lifestyle, light activity, moderate and intense activity).

RESULTS

In total, the prevalence of physical inactivity was 31.14%. The profile of this group has a lower level of education and unemployment (P<.05), presenting a higher prevalence of problems during childbirth, which required a caesarean section, as well as problems after birth in the newborn (P<.05).

CONCLUSIONS

Physical inactivity is highly prevalent among pregnant women. Due to the benefits (or non-harm) attributed to exercise during pregnancy. Further efforts should be taken to overcome the barriers to promote activities among pregnant women who are younger, less well educated, and unemployed and those with multiple children and a lower income are less likely to engage in an adequate amount of physical activity, aware of the importance of doing it, resolving doubts and allaying fears that may arise from a poor understanding of the mechanism of its benefit.

Predictors of physical activity among Chinese pregnant women during the first trimester: A cross-sectional study

Physical activity during pregnancy has numerous health benefits for the woman and the foetus. The current study investigated physical activity engagement and its predictors among pregnant Chinese women during the first trimester. A total of 687 pregnant women completed the Pregnancy Physical Activity Questionnaire. Bivariate and multivariate logistic regression were used to analyse the data. The current physical activity guidelines were not met by 64.3% of respondents. Women with higher levels of physical activity self-efficacy (aOR = 0.96; 95% CI: 0.92-0.99) and social support (aOR = 0.95; 95% CI: 0.94-0.97) had lower odds of not meeting the current physical activity guidelines. Women who were aged < 35 years (aOR = 1.85; 95% CI: 1.02-3.34), had lower education (aOR = 1.63; 95% CI: 1.04-2.55), were primiparous (aOR = 11.03; 95% CI: 6.98-17.44), were unsure of their delivery mode (aOR = 2.32; 95% CI: 1.95-5.64), and those who had higher levels of pregnancy-associated discomfort (aOR = 1.10; 95% CI: 1.03-1.19) had higher odds of not meeting the current physical activity guidelines. The current study suggests that healthcare professionals should assess physical activity engagement during routine antenatal care and increase efforts to strengthen pregnant women's self-efficacy and social support to promote physical activity engagement during the first trimester.

Utilization of the internet for physical activity and diet information and its influence on pregnant women's lifestyle habits in Qatar

Background

Maintaining a healthy lifestyle during pregnancy is essential. With the increasing availability of the internet, pregnant women have access to a wealth of information related to physical activity (PA) and healthy diets.

Objectives

The study aims to investigate the extent of internet usage by pregnant women attending antenatal clinics in Qatar to obtain information about PA and healthy diets, identify associated factors, and evaluate the impact of this information on their lifestyle habits.

Methods

A cross-sectional study was conducted in six randomly selected public antenatal clinics in Qatar. Pregnant women aged ≥18 years in any trimester were recruited using a probability sampling technique. Data were collected through self-administered questionnaires. Descriptive and analytic statistics were employed for data analysis.

Results

A total of 327 pregnant women (mean age of 29.5 years ± 4.0) completed and returned the questionnaire (response rate: 87.5%). Among the participants, 54.5% used the internet to obtain information about PA, while 72% sought online diet-related information. Factors such as age (26-35 years), tertiary education, employment status, and being primigravidae were associated with a higher likelihood of using the internet for healthy lifestyles information. Participants who reported using the internet for PA information a great deal were more likely to increase their PA during pregnancy compared to those who used it somewhat or very little (57.6, 26.8, and 5.0%, p < 0.001; respectively). Similarly, those who used the internet for diet information a great deal were more likely to increase their fruit and vegetable consumption compared to those who used it somewhat, or very little (84.2, 68.5, and 63.6%, p = 0.038; respectively). Also, participants who used the internet for diet information a great deal were more likely to decrease the amount of sugary and fatty foods they ate compared to women who used the internet somewhat or very little (61.4, 45.2, and 18.2%, p < 0.001; respectively) and (50.9, 30.4, and 18.2%, p = 0.001; respectively).

Conclusion

Many pregnant women use the internet to access information about PA and diet, and greater use is associated with more positive lifestyle changes. This study provides useful information to consider when designing intervention programs for pregnant women about adopting and maintaining healthy lifestyles.

Physical Activity and Self-Perception of Mental and Physical Quality of Life during Pregnancy: A Systematic Review and Meta-Analysis

Self-perception of health status (quality of life) is considered one of the best indicators of health and well-being. However, during pregnancy, it could be impacted not only by physiological and anatomical changes, but by poor lifestyle habits like high sedentary behaviour or bad nutrition. This study assesses the effects of physical activity RCT interventions during pregnancy on both mental and physical components of quality of life. A systematic review and two meta-analyses were performed (PROSPERO registration number: CRD42022370467). Of the 207 articles captured both in English and Spanish, seven articles were deemed eligible for inclusion. The two analyses performed found that physically active pregnant women had better scores of mental self-perception of quality of life (z = 2.08, p = 0.04; SMD = 0.34, 95% CI = 0.02, 0.67, I2 = 76%, Pheterogeneity = 0.0004) and in physical self-perceived health status (z = 2.19, p = 0.03; SMD = 0.33, 95% CI = 0.03, 0.63, I2 = 71%, Pheterogeneity = 0.002) compared to control group pregnant women. Physical activity interventions could potentially increase mental and physical self-perception of quality of life during pregnancy.

Maternal Social Loneliness Detection Using Passive Sensing Through Continuous Monitoring in Everyday Settings: Longitudinal Study

BACKGROUND

Maternal loneliness is associated with adverse physical and mental health outcomes for both the mother and her child. Detecting maternal loneliness noninvasively through wearable devices and passive sensing provides opportunities to prevent or reduce the impact of loneliness on the health and well-being of the mother and her child.

OBJECTIVE

The aim of this study is to use objective health data collected passively by a wearable device to predict maternal (social) loneliness during pregnancy and the postpartum period and identify the important objective physiological parameters in loneliness detection.

METHODS

We conducted a longitudinal study using smartwatches to continuously collect physiological data from 31 women during pregnancy and the postpartum period. The participants completed the University of California, Los Angeles (UCLA) loneliness questionnaire in gestational week 36 and again at 12 weeks post partum. Responses to this questionnaire and background information of the participants were collected through our customized cross-platform mobile app. We leveraged participants' smartwatch data from the 7 days before and the day of their completion of the UCLA questionnaire for loneliness prediction. We categorized the loneliness scores from the UCLA questionnaire as loneliness (scores≥12) and nonloneliness (scores<12). We developed decision tree and gradient-boosting models to predict loneliness. We evaluated the models by using leave-one-participant-out cross-validation. Moreover, we discussed the importance of extracted health parameters in our models for loneliness prediction.

RESULTS

The gradient boosting and decision tree models predicted maternal social loneliness with weighted F1-scores of 0.897 and 0.872, respectively. Our results also show that loneliness is highly associated with activity intensity and activity distribution during the day. In addition, resting heart rate (HR) and resting HR variability (HRV) were correlated with loneliness.

CONCLUSIONS

Our results show the potential benefit and feasibility of using passive sensing with a smartwatch to predict maternal loneliness. Our developed machine learning models achieved a high F1-score for loneliness prediction. We also show that intensity of activity, activity pattern, and resting HR and HRV are good predictors of loneliness. These results indicate the intervention opportunities made available by wearable devices and predictive models to improve maternal well-being through early detection of loneliness.

Influence of Physical Activity during Pregnancy on Type and Duration of Delivery, and Epidural Use: Systematic Review and Meta-Analysis

Cesarean delivery may increase the need for anesthesia administration, thereby causing potential risks to both maternal and fetal health. This article aimed to investigate the effect of physical activity during pregnancy on the type of delivery, the duration of labor, and the use of epidurals (registration No.: CRD42022370646). Furthermore, 57 RCTs (n = 15301) were included showing that physical activity could decrease the risk of cesarean section (z = 3.22, p = 0.001; RR = 0.87, 95% CI = 0.79, 0.95, I2 = 37%, Pheterogeneity = 0.004), and 32 RCTs (n = 9468) showed significant decreases in instrumental delivery through performing physical activity (z = 3.48, p < 0.001; RR = 0.84, 95% CI = 0.76, 0.93, I2 = 0%, Pheterogeneity = 0.63). A significant decrease in the 15 RCTs' (n = 4797) duration of first stage labor was found in physically active pregnant women (z = 2.09, p = 0.04; MD = -62.26, 95% CI = -120.66, -3.85, I2 = 93%, Pheterogeneity < 0.001) compared to those not active. Prenatal physical activity could decrease the risk of cesarean section and instrumental delivery and the duration of first stage labor.

Physical activity: associations with health and summary of guidelines

The understanding of how physical activity and insufficient physical activity are associated with health outcomes has increased considerably over the past decades. Along with physical activity, the evidence on the associations between sedentary behavior and health has increased, which has resulted in the introduction of recommendations of sedentary behavior. In this article, we 1) present terminology for physical activity and sedentary behavior epidemiology, 2) show the relevant scientific evidence on associations of physical activity and sedentary behavior with selected health-related outcomes and 3) introduce the global guidelines for physical activity and sedentary behavior by the World Health Organization (WHO). Health-related outcomes include cardiovascular morbidity and mortality, total mortality, glucose regulation and type 2 diabetes, adiposity, overweight, obesity, cancer, musculoskeletal and bone health, brain health, and quality of life. These health-related outcomes are reflected across age groups and some population groups, such as pregnant and postpartum women. Furthermore, we discuss physical activity levels across Nordic countries and over time. For the Nordic Nutrition Recommendations, shared common physical activity guidelines were not developed. Instead, each country has created their own guidelines that are being referenced in the article, along with the global WHO guidelines.

Obstetric, maternal, and neonatal outcomes after Pilates exercise during pregnancy: A systematic review and meta-analysis

BACKGROUND

One of the major exercises to improve the psychological and physical functions of pregnant women is Pilate's exercises. The aim of this study is to collect evidence about Pilates exercise effects on many consequences in pregnant women, such as maternal and neonatal outcomes and obstetric outcomes.

METHODS

PubMed, Clinical Key, Cochrane Library, Scopus, Embase, and Web of Science were scoured from their inception. Research comparing Pilates during pregnancy to other methods, or to the control was included. For randomized controlled trials (RCTs), The researcher utilized the Cochrane risk of bias tool; for non-RCTs, risk of bias tool to assess non-randomized studies of interventions, was used for cohort studies, and the national heart, lung, and blood institute tool. Meta-analysis was done using the Review manager 5.4. For continuous data, calculated the mean difference and 95% confidence interval (CI), and the risk ratio (RR) and 95% CI for dichotomous data.

RESULTS

Finally, 13 studies included with a total number of 719 pregnant women. The analysis showed that the Pilates group was significantly more likely to deliver vaginally than the control group (RR = 1.21, 95% CI [1.05 to 1.41], P value = .009). Women in the Pilates group were significantly lower than the control group to have Cesarean delivery (RR = 0.67, 95% CI [0.48-0.94], P value = .02). Moreover, Pilates-treated women were less likely to gain weight during pregnancy than control (mean difference = -3.48, 95% CI [-6.17 to -0.79], P value = .01).

CONCLUSION

Pilates exercise improved the outcomes of pregnant women. It decreases the rate of Cesarean delivery and the time of delivery. Moreover, Pilates has a role in decreasing weight gain in pregnant women. As a result, that may improve the pregnancy experience for women. However, more RCTs needed with larger sample sizes to assess the Pilates effect on neonatal outcomes.

Pre-pregnancy participation and performance in world's largest cross-country ski race as a proxy for physical exercise and fitness, and perinatal outcomes: Prospective registry-based cohort study

OBJECTIVE

Investigate associations between pre-pregnancy participation and performance in a demanding cross-country ski race (proxy for exercise volume and fitness) and perinatal outcomes. Pre-registered protocol: osf.io/aywg2.

DESIGN

Prospective cohort study.

SETTING

Based on entire overlap between the Vasaloppet registry and the population-based Swedish Pregnancy Register.

SAMPLE

All female Vasaloppet participants 1991-2017 with subsequent singleton delivery (skiers), and age- and county-matched non-skiers.

METHODS

We calculated odds ratios (ORs) for non-skiers versus skiers (model 1) and, among skiers, by performance (model 2), in Bayesian logistic regressions adjusted for socio-demographics, lifestyle factors, and comorbidities. We repeated calculations adjusting for early pregnancy body mass index (potential mediator) and explored robustness (selection/exposure settings; multiple comparisons correction).

MAIN OUTCOME MEASURES

Twenty-nine important perinatal outcomes, predefined based on existing expert consensus.

RESULTS

Non-skiers (n = 194 384) versus skiers (n = 15 377) (and slower versus faster performance, not shown) consistently had higher odds of gestational diabetes mellitus (GDM) (OR 1.70, 95% highest density interval: 1.40-2.09), excessive gestational weight gain (GWG) (1.28, 1.22-1.38), psychiatric morbidity (1.60, 1.49-1.72), any caesarean section (CS) (1.34, 1.28-1.40), elective CS (1.39, 1.29-1.49), and large-for-gestational-age babies (>90th percentile, 1.11, 1.04-1.18); lower odds of inadequate GWG (0.83, 0.79-0.88); and no associations with fetal/neonatal complications (e.g. preterm birth [1.09, 0.98-1.20], small for gestational age [SGA] [1.23, 1.05-1.45]). Adjustment for body mass index attenuated associations with excessive (1.20, 1.14-1.30) and inadequate GWG (0.87, 0.83-0.92) and large for gestational age (1.07, 1.00-1.13).

CONCLUSION

Non-skiers compared with skiers, and slower versus faster performance, consistently displayed higher odds of GDM, excessive GWG, psychiatric morbidity, CS and large-for-gestational-age babies; and lower odds of inadequate GWG, after adjustment for socio-demographic and lifestyle factors and comorbidities. There were no associations with fetal/neonatal complications.

Can we hit prenatal depression and anxiety through HIIT? The effectiveness of online high intensity interval training in pregnant women during the COVID-19 pandemic: a randomized controlled trial

BACKGROUND

In recent years high intensity interval training (HIIT) has grown in popularity. However, it rarely represents training interventions in experimental studies in pregnant populations. Therefore, in this study we aimed to assess changes in depressive symptoms, fear of childbirth, fear of Covid-19 and quality of life after an 8-week supervised online HIIT program, compared to an educational (self-performed physical activity) program.

METHODS

We conducted a randomized control trial among 54 Caucasian women in uncomplicated, singleton pregnancy (age 32 ± 4 years, 22 ± 4 week of gestation; mean ± SD). There were 34 women in the experimental group, who participated in an 8-week high intensity interval training program (HIIT group). The comparative group was constituted of 20 pregnant women who attended 8-week educational program (EDU group).

RESULTS

The most important finding was that mental health improved somewhat in both groups after the intervention, but only the HIIT group improved statistically significantly. The positive trends in lowering the severity of depressive symptoms, fear of childbirth, and fear of Covid-19 were observed in both groups. However, the positive response to the intervention was stronger in the EDU group. As a secondary outcome, there was a significant decrease in cardiorespiratory fitness level in the EDU group, while the HIIT group maintained unchanged level of maximal oxygen uptake.

CONCLUSIONS

HIIT seems to be beneficial for women with uncomplicated pregnancies to maintain adequate quality of life and mental health. However, more research is needed to determine the effectiveness of prenatal HIIT in pregnant women in various psychological conditions.

TRIAL REGISTRATION

We conducted this study in Poland, in 2021. It was approved by the Bioethics Commission at the District Medical Chamber in Gdansk (KB-8/21). The full study protocol was registered in ClinicalTrials.gov (NCT05009433).

Effects of 8-Week Online, Supervised High-Intensity Interval Training on the Parameters Related to the Anaerobic Threshold, Body Weight, and Body Composition during Pregnancy: A Randomized Controlled Trial

We aimed to assess the effects of an 8-week, online high-intensity interval training (HIIT) program on the parameters related to the anaerobic threshold (AT), body weight, and body composition in pregnant women. A total of 69 Caucasian women with an uncomplicated singleton pregnancy (age: 31 ± 4 years; gestational age: 22 ± 5 weeks; mean ± standard deviation) were randomly allocated to either an 8-week HIIT program (HIIT group) or to a comparative 8-week educational program (EDU group). Our most important finding was that even with the 8-week progression of pregnancy and physiological weight gain, the HIIT group maintained the same level of parameters related to AT: volume of oxygen at the AT (VO2/AT), percentage of maximal oxygen uptake at the AT (%VO2max/AT), and heart rate at the AT (HR/AT). In contrast, in the EDU group we observed a substantial deterioration of parameters related to the AT. The HIIT intervention substantially reduced the fat mass percentage (median: 30 to 28%; p < 0.01) and improved the total fat-free mass percentage (median: 70% to 72%; p < 0.01). In the EDU group, the body composition did not change significantly. An online, supervised HIIT program may be used to prevent the pregnancy-related risk of excessive weight gain and reduction in exercise capacity without yielding adverse obstetric or neonatal outcomes.

The intergenerational effects of parental physical activity on offspring brain and neurocognition in humans: A scoping review

Animal models suggest physical activity (PA) has intergenerational effects on brain health and neurocognition. This scoping review compiles the human literature in this area, identifies knowledge gaps, and makes recommendations for future research. We systematically searched for experimental or observational studies conducted in humans, published in English, and reporting parental PA exposure (preconception or prenatal) and subsequent offspring brain and neurocognition. Two reviewers independently screened studies according to predetermined inclusion criteria. Fourteen studies were included (four experimental and 10 observational) reporting on 93,486 parent-child dyads (100% maternal, 0% paternal). Prenatal maternal PA exposure was examined in 10 (71%) studies, while preconception and prenatal PA exposure was examined in four (29%) studies. Maternal PA exposure was positively related to offspring (0-20y) brain and neurocognitive development in 25% of experimental studies and 100% of observational studies. Little is known about the intergenerational effects of parental PA on offspring brain and neurocognition in humans, particularly paternal preconception PA. More experimental studies with longer offspring follow-up and more objective and/or mechanistic assessments are required.

Prevalence of knowledge on maternal physical activity among pregnant women: a protocol for a systematic review

BACKGROUND

Maternal physical activity is beneficial to pregnant women, fetus and newborns. Evidence suggests that the level of physical activity in this group is not up to the expectation around the world. Lack of knowledge on the benefits of physical activity during pregnancy and not being aware of the recommendations are major reasons for this situation. Although individual studies have reported various levels of knowledge on maternal physical activity in different populations, no studies have systematically reviewed the literature to provide global evidence on the topic that is useful in initiating multinational approaches to improve maternal physical activity. The proposed study aims to systematically review prevalence of knowledge on maternal physical activity among pregnant women in different regions in the world.

METHODS

The proposed systematic review is designed according to the guidelines for conducting systematic reviews of prevalence and will be reported following the recommendations in the PRISMA statement. Quantitative cross-sectional, descriptive and observational studies published from year 2000 to 2022 will be included in the review. PubMed, Scopus, CINAHL, Embase, SPORTDiscus and Web of Science Core Collections will be searched using keywords relevant to physical activity, pregnant women and knowledge. Grey literature on the topic will be located through searching grey information sources, hand searching of reference lists and communicating with experts in the field. Screening of search results, selection and quality assessment of studies and data extraction will be independently performed by two reviewers. Assistance of a third reviewer will be sought to resolve any disagreement during the selection and quality assessment steps. After appraising the quality and consistency of selected studies, a premade data collection form will be used for data extraction. Narrative synthesis approach will be used in this review to analyze the evidence in primary studies.

DISCUSSION

The proposed review will summarize evidence on the level of knowledge on maternal physical activity among pregnant women in different populations and delineate interregional discrepancies. The study will locate high priority regions with poor knowledge and identify elements of knowledge that needs attention.

Pelvic inlet area is associated with birth mode

INTRODUCTION

To determine whether a pelvis is wide enough for spontaneous delivery has long been the subject of obstetric research. A number of variables have been proposed as predictors, all with limited accuracy. In this study, we use a novel three-dimensional (3D) method to measure the female pelvis and assess which pelvic features influence birth mode. We compare the 3D pelvic morphology of women who delivered vaginally, women who had cesarean sections, and nulliparous women. The aim of this study is to identify differences in pelvic morphology between these groups.

MATERIAL AND METHODS

This observational study included women aged 50 years and older who underwent a CT scan of the pelvis for any medical indication. We recorded biometric data including height, weight, and age, and obtained the obstetric history. The bony pelvis was extracted from the CT scans and reconstructed in three dimensions. By placing 274 landmarks on each surface model, the pelvises were measured in detail. The pelvic inlet was measured using 32 landmarks. The trial was registered at the German Clinical Trials Register DRKS (DRKS00017690).

RESULTS

For this study, 206 women were screened. Exclusion criteria were foreign material in the bony pelvis, unknown birth mode, and exclusively preterm births. Women who had both a vaginal birth and a cesarean section were excluded from the group comparison. We compared the pelvises of 177 women between three groups divided by obstetric history: vaginal births only (n = 118), cesarean sections only (n = 21), and nulliparous women (n = 38). The inlet area was significantly smaller in the cesarean section group (mean = 126.3 cm² ) compared with the vaginal birth group (mean = 134.9 cm² , p = 0.002). The nulliparous women were used as a control group: there was no statistically significant difference in pelvic inlet area between the nulliparous and vaginal birth groups.

CONCLUSIONS

By placing 274 landmarks on a pelvis reconstructed in 3D, a very precise measurement of the morphology of the pelvis is possible. We identified a significant difference in pelvic inlet area between women with vaginal delivery and those with cesarean section. A unique feature of this study is the method of measurement of the bony pelvis that goes beyond linear distance measurements as used in previous pelvimetric studies.

Patterns of physical activity and sedentary behavior before and during pregnancy and cardiometabolic outcomes

OBJECTIVE

To assess how physical activity and sedentary behavior change from pre-pregnancy to pregnancy, and if pre-pregnancy and pregnancy physical activity and sedentary behavior are related to gestational weight gain, blood pressure, or blood glucose across pregnancy.

DESIGN

Secondary analysis of two prospective cohort studies.

SETTING

Prenatal research centers in Pittsburgh, PA and Iowa City, IA.

PARTICIPANTS

Pregnant individuals (n=131), 18-45 years old, of any BMI, with no medical condition limiting physical activity or use of hypertension/diabetes medications.

METHODS

Participants self-reported physical activity and sedentary behavior pre-pregnancy and in each trimester using validated questionnaires. Blood pressure, blood glucose, and weight were obtained from study visits and/or electronic medical records. Multivariable regression examined associations between pre-pregnancy, trimester-specific, and changes in physical activity and sedentary behavior with weight gain and blood pressure outcomes in each trimester, and blood glucose in the second trimester.

RESULTS

Compared to pre-pregnancy, physical activity was lower in each trimester, and sedentary behavior was higher in each trimester (p<0.05). Increasing physical activity from pre-pregnancy levels was associated with lower first trimester SBP (p<0.05). Unexpectedly, higher pre-pregnancy physical activity was associated with higher SBP in the first trimester (p=0.02) and higher weight gain in the third trimester (p=0.02). Higher and increasing sedentary behavior was associated with greater weight gain in the third trimester (p=0.03).

CONCLUSION

Future research should investigate the opportune time (before or during pregnancy) to deliver behavior modification interventions that could prevent excessive gestational weight gain or elevated blood pressure to improve maternal health outcomes.

Population characteristics associated with adherence to prenatal group-based exercise programs

Community-based supervised group exercise may be an effective option to increase activity levels throughout pregnancy. Previous studies that have explored predictors of low adherence to exercise during pregnancy have not examined group-based settings. We analysed an international cohort of 347 pregnant women who participated in group-based prenatal exercise interventions (from <20 weeks to 34-36 weeks pregnant). Probable adherence predictors informed by previous literature that were assessed included: pre-pregnancy physical activity level and body mass index (BMI) classification, age, number of previous pregnancies, and education level. Adherence was measured by attendance. Adjusted odds ratios (aOR) and 95% confidence intervals (CI) were calculated to explore the relationship between the selected predictors and high adherence (≥70%). Post-secondary education level versus only secondary (aOR 5.28; CI 1.67; 16.72) or primary level (aOR 13.82; CI 4.30; 44.45) presented greater likelihood to have high adherence to the exercise intervention than low adherence. Future research and public health initiatives should consider implementing strategies to overcome education-related barriers to improve accessibility to prenatal exercise.

The short-term effect of a mHealth intervention on gestational weight gain and health behaviors: The SmartMoms Canada pilot study

Gestational weight gain (GWG) has been shown to impact several maternal-infant outcomes. Since healthcare provider guidance on weight gain and healthy behaviors alone has failed to help women to meet guidelines during pregnancy, a practical adjunctive approach is to deliver evidence-based behavior change programs through mobile interventions. The present study aimed to assess the short-term effect of the SmartMoms Canada app to promote adequate GWG and healthy behaviors. Twenty-nine pregnant women were recruited in this app-based intervention trial to test whether a higher app usage (≥ 3.8 min·week^-1) between 12-20 gestational weeks and 24-28 gestational weeks improved GWG, diet, physical activity, and sleep, compared to women with a lower app usage (< 3.8 min·week^-1). Two-way mixed ANOVA for repeated measures was used to estimate the effect of the app usage and time, as well as their interaction on GWG and healthy behaviors. The likelihood ratio was used to examine the association between app usage categorization and GWG classification. Cramer's V statistic was used to estimate the effect size for interpretation of the association. Pregnant women using the SmartMoms Canada app more frequently had a higher moderate-to-vigorous physical activity (MVPA) daily average when compared with women with a lower usage (mean difference: 17.84 min/day, 95% CI: 2.44; 33.25). A moderate effect size (28.6% vs. 15.4%; Cramer's V = 0.212) was found for the association between app categorization and rate of GWG, representing a greater adherence to the GWG guidelines in women in the higher app usage group vs. the lower app usage group. Considering other physical activity, diet, and sleep variables, no app categorization effect was observed. A short-term higher usage of SmartMoms Canada app has a positive effect on objectively-measured MVPA.

Sports Obstetrics: Implications of Pregnancy in Elite Sportswomen, a Narrative Review

Increasing numbers of females are participating in elite sports, with a record number having competed at the Tokyo Olympic Games. Importantly, the ages of peak performance and fertility are very likely to coincide; as such, it is inevitable that pregnancy will occur during training and competition. Whilst there is considerable evidence to promote regular exercise in pregnancy, with benefits including a reduction in hypertensive disorders, gestational diabetes, and reduced rates of post-natal depression, few studies have been conducted which include elite athletes. Indeed, there are concerns that high-intensity exercise may lead to increased rates of miscarriage and preterm labour, amongst other pregnancy-related complications. There is minimal guidance on the obstetric management of athletes, and consequently, healthcare professionals frequently adopt a very conservative approach to managing such people. This narrative review summarises the evidence on the antenatal, intrapartum, and postpartum outcomes in elite athletes and provides recommendations for healthcare providers, demonstrating that generally, pregnant athletes can continue their training, with a few notable exceptions. It also summarises the physiological changes that occur in pregnancy and reviews the literature base regarding how these changes may impact performance, with benefits arising from pregnancy-associated cardiovascular adaptations at earlier gestations but later changes causing an increased risk of injury and fatigue.

Development of the Get Active Questionnaire for Pregnancy: Breaking down barriers to prenatal exercise

Evidence-based guidelines represent the highest level of scientific evidence to identify best-practices for clinical/public health. However, the availability of guidelines do not guarantee their use, targeted knowledge translation strategies and tools are necessary to help promote uptake. Following publication of the 2019 Canadian Guideline for Physical Activity throughout Pregnancy, the Get Active Questionnaire for Pregnancy, and an associated Health Care Provider Consultation Form for Prenatal Physical Activity were developed to promote guideline adoption and use amongst pregnant individuals and health care providers. This paper describes the process of developing these tools. First, a survey was administered to qualified exercise professionals to identify the barriers and facilitators in using existing prenatal exercise screening tools. A Working Group of researchers and stakeholders then convened to develop an evidence-informed exercise pre-participation screening tool for pregnant individuals, building from previous tool and survey findings. Finally, end-user feedback was solicited through a survey and key informant interviews to ensure tools are feasible and acceptable to use in practice. The uptake and use of these documents by pregnant individuals, exercise and health care professionals will be assessed in future studies. Novelty Bullets • Evidence supports the safety/benefits of exercise for most pregnant individuals; however, exercise is not recommended for a small number of individuals with specific medical conditions. • The Get Active Questionnaire for Pregnancy and Health Care Provider Consultation Form for Physical Activity during Pregnancy identify individuals where prenatal exercise may pose a risk, while reducing barriers to physical activity participation for the majority of pregnant individuals.

Can Group Exercise Programs Improve Health Outcomes in Pregnant Women? An Updated Systematic Review

Current scientific evidence supports the recommendation to initiate or continue physical exercise in healthy pregnant women. Group exercise programs have positive effects on improving health, well-being, and social support. In 2015, a systematic review was provided to evaluate the evidence on the effectiveness of group exercise programs in improving pregnant women's and newborns' health outcomes and to assess the content of the programs. This review aims to update this knowledge between 2015 and 2020. The exercise program designs were analyzed with the Consensus of Exercise Reporting Template (CERT) model, the compliance with the current guidelines, and effectiveness in the maternal health and fitness parameters. Three databases were used to conduct literature searches. Thirty-one randomized control trials were selected for analysis. All studies followed a supervised group exercise program including aerobic, resistance, pelvic floor training, stretching, and relaxation sections. Group interventions during pregnancy improved health and fitness outcomes for the women and newborns, although some gaps were identified in the interventions. Multidisciplinary teams of exercise and health professionals should advise pregnant women that group exercise improves a wide range of health outcomes for them and their newborns.

Uncovering Barriers to Prenatal Physical Activity and Exercise Among South African Pregnant Women: A Cross-Sectional, Mixed-Method Analysis

Background

The barriers to prenatal physical activity and exercise have been widely reported in the literature, highlighting context-specific challenges. However, generally, research on prenatal physical activity and exercise among pregnant women in South Africa is rare; and particularly concerning the barriers to their prenatal physical activity practice. This study assessed the barriers to physical activity participation among pregnant women in the Eastern Cape, South Africa.

Methods

This was a sequential explanatory mixed method, predominantly quantitative study involving 1,082 pregnant women. A structured self-administered questionnaire on perceived barriers to physical participation was applied to collect quantitative data; while a subset of 15 pregnant women participated in individual in-depth semi-structured interviews to augment quantitative data. Quantitative and qualitative data were analyzed using descriptive statistics and thematic analysis, respectively.

Results

The results of the quantitative analysis presented major barriers: lack of advice on prenatal physical activity and inadequate or conflicting information about prenatal physical activity; tiredness; work commitments; discomfort; lack of time; low energy; non-accessibility to physical activity; lack of financial resources, and safety concerns for the mother and the baby. Qualitatively, the barriers identified relate to four main themes: individual, lack of information, lack of resources, and environmental barriers.

Conclusion

The major barriers cited by the women were tiredness, lack of time, discomfort, and low energy. They also include lack of support, advice and information about prenatal physical activity. The multiple constraining factors responsible for low or non-prenatal physical activity of pregnant women in this setting highlight the need to tailor interventions to address their individual uniquely perceived barriers.

Be Healthy in Pregnancy (BHIP): A Randomized Controlled Trial of Nutrition and Exercise Intervention from Early Pregnancy to Achieve Recommended Gestational Weight Gain

A randomized two-arm prospective superiority trial tested the efficacy of a novel structured and monitored nutrition (bi-weekly counselling for individualized energy and high dairy protein diet) and exercise program (walking goal of 10,000 steps/day) (intervention) compared to usual care (control) in pregnant women to achieve gestational weight gain (GWG) within current recommendations. Women recruited in communities in southern Ontario, Canada were randomized at 12–17 weeks gestation with stratification by site and pre-pregnancy BMI to intervention (n = 119) or control (n = 122). The primary outcome was the proportion of women who achieved GWG within the Institute of Medicine recommendations. Although the intervention compared to control group was more likely to achieve GWG within recommendations (OR = 1.51; 95% CI (0.81, 2.80)) and total GWG was lower by 1.45 kg (95% CI: (−11.9, 8.88)) neither reached statistical significance. The intervention group achieved significantly higher protein intake at 26–28 week (mean difference (MD); 15.0 g/day; 95% CI (8.1, 21.9)) and 36–38 week gestation (MD = 15.2 g/day; 95% CI (9.4, 21.1)) and higher healthy diet scores (22.5 ± 6.9 vs. 18.7 ± 8.5, p < 0.005) but step counts were similar averaging 6335 steps/day. Pregnancy and infant birth outcomes were similar between groups. While the structured and monitored nutrition with counselling improved diet quality and protein intake and may have benefited GWG, the exercise goal of 10,000 steps/day was unachievable. The results can inform future recommendations for diet and physical activity in pregnancy.

Maternal Physical Activity at Term and Spontaneous Labor: A Case-Crossover Study

BACKGROUND

This study assessed associations between antenatal physical activity and the onset of spontaneous labor (SL).

METHODS

Data were taken from 541 participants in the third pregnancy, infection, and nutrition study who had no contraindications to antenatal physical activity. An interviewer-administered questionnaire assessed labor triggers, gestational age at birth, and physical activity within the week (24 h to 7 d) and the 24-hour period (0-24 h) prior to SL. A case-crossover design examined the association between physical activity (recreational, occupational, or any) and the risk of onset of SL within the subsequent 24 hours.

RESULTS

Overall, 21% (any), 26% (recreational), and 14% (occupational) of participants reported physical activity during the week; whereas 5% (any), 7% (recreational), and 3% (occupational) reported physical activity during the 24-hour period, prior to SL onset. Participants who reported any or occupational physical activity during the 24-hour period had a decreased likelihood of SL within the subsequent 24 hours, while participants who reported at least 30 minutes of recreational physical activity had an increased likelihood. Results remained consistent among early, full, or postterm participants.

CONCLUSION

Recreational, but not occupational, physical activity at term may increase the likelihood of SL; however, the authors cannot rule out reverse causality.

Physical exercise in pregnancy: benefits, risks and prescription

OBJECTIVES

The aim of this article is to provide a comprehensive literature review, gathering the strongest evidence about the risks and benefits and the prescription of physical exercise during pregnancy.

CONTENT

Regular physical exercise during pregnancy is associated with numerous benefits. In general women are not adequately advised on this matter. Along with their concerns regarding the potential associated risks, it contributes to the abandonment or refusal to start exercising during pregnancy. A systematic review was conducted in MEDLINE including articles considered to have the highest level of scientific evidence. Fifty-seven articles, including 32 meta-analysis, 9 systematic reviews and 16 randomized controlled trials were included in the final literature review.

SUMMARY

Exercise can help preventing relevant pregnancy related disorders, such as gestational diabetes, excessive gestational weight gain, hypertensive disorders, urinary incontinence, fetal macrosomia, lumbopelvic pain, anxiety and prenatal depression. Exercise is not related with an increased risk of maternal or perinatal adverse outcomes. Compliance with current guidelines is sufficient to achieve the main benefits, and exercise type and intensity should be based on woman's previous fitness level.

OUTLOOK

Exercise in pregnancy is safe for both mother and fetus, contributing to prevent pregnancy related disorders. Exercise type and intensity should be adapted to woman's previous fitness level, medical history and characteristics of the ongoing pregnancy.

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.

Influence of ambient temperature and diurnal temperature variation on the premature rupture of membranes in East China: A distributed lag nonlinear time series analysis

BACKGROUND

Extreme ambient temperature has an adverse effect on pregnancy outcomes, but the conclusions have been inconsistent. The influence of ambient temperature and diurnal temperature variation on the premature rupture of membranes (PROM) needs further study.

METHODS AND FINDINGS

The daily data of PROMs, daily meteorological and air pollutant were obtained. After controlling for potential confounding factors, the quasi-Poisson generalized additive model (GAM) combined with the distributed lag nonlinear model (DLNM) was used to analyze the association between temperature or diurnal temperature variation and PROM, including preterm premature rupture of membranes (PPROM) and term premature rupture of membranes (term PROM). Compared with the median temperature(18.7 °C), the mean temperature of 5-7 days lagging beyond 31.5 °C and below -1.5 °C was positively correlated with PROM; the mean temperature had more sensitive effect on the term PROM. Exposure to extremely high temperatures (97.5th percentile, 32 °C) had a 6-day lagging relative risk (RR) (95% CI: 1.005-1.160) of 1.08 for PROM and a 6-day lagging RR of 1.079 (95% CI: 1.005-1.159) for term PROM; Exposure to a high diurnal temperature variation (diurnal temperature variation greater than 16 °C) was positively correlated with the term PROM. Compared with the 2.5th percentile diurnal temperature variation (2 °C), exposure to the 95th percentile diurnal temperature variation (17 °C) significantly increased the risk of term PROM (RR: 1.229, 95% CI: 1.029-1.467).

CONCLUSIONS

Exposure to a high-temperature and a high diurnal temperature variation environment will increase the relative risks of PROM. For pregnant women in the 3rd trimester, it is important to reduce exposure to extremely high-temperatures and greater diurnal temperature changes.

Physical activity in gestational trimesters and perinatal outcomes in SUS puerperal women

OBJECTIVE

Test the association between the practice of physical activity (PA) according to the gestational trimesters and the occurrence of cesarean delivery, prematurity, and low birth weight in puerperal women assisted in the Unified Health System of Santa Catarina, Brazil.

METHODS

A cross-sectional study was conducted with a probabilistic sample of puerperal women who gave birth in public maternity hospitals in Santa Catarina from January to August 2019. The cesarean delivery outcome was self-reported, and information on premature birth (< 37 gestational weeks) and low birth weight (< 2,500 grams) were obtained from medical records. The practice of PA during pregnancy and according to each trimester was self-reported. Multivariate Logistic Regression analyses and interviews with 3,580 puerperal women were carried out.

RESULTS

PA practice during any period of pregnancy was reported by 20.6% of the sample, with a gradual reduction in prevalence according to the gestational trimester (16.2%, 15.4%, and 12.8%). The highest prevalences of outcomes concerning the total sample were observed in puerperal women who did not practice PA in the third trimester, with 43.9% for cesarean delivery, 7.7% for low birth weight, and 5.5% for premature birth. The odds of cesarean delivery (OR = 1.40; 95%CI 1.10–1.76) and low birth weight (OR = 1.99; 95%CI 1.04–3.79) were, respectively, 40% and 99% higher among puerperal women who did not practice PA in the third trimester of pregnancy when compared to those who practiced PA. There was no association between PA practice and prematurity.

CONCLUSION

Puerperal women who did not practice PA in the third trimester of pregnancy were more likely to have cesarean delivery and low birth weight newborns.

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.

Low Back Pain during Pregnancy and Delivery Outcomes

AIM

To evaluate low back pain (LBP) incidence and impact throughout pregnancy in terms of women's well-being and delivery outcomes.

MATERIAL AND METHODS

Cross-sectional prospective study conducted on singleton pregnancies at ≥37th gestational age admitted for delivery. Localization of LBP, intensity and frequency as well as derived functional disability status were assessed with a self-reported questionnaire. Main delivery outcomes including mode of delivery, and maternal or neonatal complications were recorded.

RESULTS

A total of 229 women participated in the study. LBP prevalence amounted to 55.9%, with the pain already present before pregnancy in 14.0% of the cases. The pain was mostly localized in the lower back (40.6%), symphysis (23.3%), and coccyx (20.5%). Both the frequency and intensity of pain gradually increased significantly during pregnancy, reaching 20 days/month (IQR=10-30) and 6/10 points (IQR=5-8) on a visual analog scale in the 3rd trimester (p<0.05). The extent of functional impairment also progressively increased up to 39/100 points (IQR=25-55, p<0.05). Women affected by LBP during pregnancy had a higher cesarean section rate during labor than women without LBP (11.9% vs. 28.9%, p<0.05). The risk was also significant in the multivariate analysis (OR=4.0, 95%CI=1.1-15.0, p<0.05). There was no difference in the rate of operative vaginal births or in the other outcomes considered.

CONCLUSIONS

LBP is a common issue in pregnant women, accounting for increasing morbidity and invalidity, and leading to an increased cesarean section risk during labor.