Exercise during pregnancy and the postpartum period

Interval training and cardiometabolic health in reproductive-aged females

Physical activity and exercise training are especially important for reproductive-aged females as exercise-induced health benefits can also affect their infants. However, levels of physical inactivity remain high among females in this age group, before, during, and after pregnancy. There is a great need for practical and feasible exercise modes to increase adherence to exercise in this population, and interval training may be a time-efficient training modality. Interval training is a form of exercise involving intermittent bouts of intense effort interspersed with recovery periods of rest or lower-intensity exercise. A substantial amount of research indicates that interval training induces superior cardiometabolic health benefits compared with iso-energetic moderate-intensity continuous exercise. This review provides a comprehensive overview of research on interval training interventions in reproductive-aged females across various life stages, focusing on the cardiometabolic health benefits. We discuss the potential role of interval training in premenopausal females with overweight/obesity, polycystic ovary syndrome, and subfertility, as well as the potential influence of oral contraceptives on cardiometabolic adaptations to interval training. Furthermore, this review also highlights recent findings supporting the beneficial role of high-intensity interval training for cardiometabolic health outcomes during pregnancy. In summary, the existing evidence suggests that interval training can improve several cardiometabolic and reproductive outcomes in females spanning different life stages. However, more research is needed to further strengthen the evidence-base for physical activity recommendations for females in their reproductive years of life.

Benefits of Resistance Training During Pregnancy for Maternal and Fetal Health: A Brief Overview

Research demonstrates resistance training is not only safe but also beneficial for pregnant women. However, exercise recommendations for pregnant women still minimize the importance of resistance exercise and provide minimal guidance. With a large increase in strength-focused sports among women, it is critical to re-evaluate the risk/benefit ratio of these exercises and ensure the latest recommendations reflect the latest clinical research. The purpose of this review is to highlight the safety and benefits of resistance training for both maternal and fetal health, particularly focusing on recent work. Relevant research involving resistance training during pregnancy was accessed and analyzed via a quasi-systematic search. Results demonstrate that appropriate prenatal resistance training can help alleviate some of the common symptoms of pregnancy, such as fatigue, back pain, and poor mental health. Resistance exercise can assist with glucose control in gestational diabetes mellitus, as well as decrease the risk of infant macrosomia and childhood metabolic dysfunction associated with uncontrolled gestational diabetes. Resistance training can also increase the likelihood of a vaginal delivery, which is beneficial for both mother and baby. Concerning fetal health, resistance training increases uterine blood flow, decreases the risk of neonatal macrosomia, and improves cognitive function and metabolic health in childhood. As with all forms of exercise, pregnant women should avoid resistance exercises that involve the supine position for extended bouts of time, trauma (or risk of trauma) to the abdomen, ballistic movements, movements that rely heavily on balance, and conditions that prohibit appropriate temperature control. With these considerations in mind, resistance training's benefits far surpass the lack of risk to the fetus. Resistance training is a safe and effective way to improve and maintain physical fitness during pregnancy and represents no risk to fetal health and development. Thus, healthcare providers should recommend resistance training for pregnant women.

New Public Health and Sport Medicine Institutions Guidelines of Physical Activity Intensity for Pregnancy-A Scoping Review

Background: Before starting PA, pregnant women should select the appropriate type of training and adjust its components to the development of pregnancy and her capabilities. This review aimed to analyze current recommendations for pregnant women on methods for determining and assessing PA intensity levels and characterize the extent and nature of the information provided to pregnant women in official documents published by public health and sports medicine institutions. Methods: The review was conducted as per the PRISMA Extension for Scoping Reviews (PRISMA-ScR). We searched scientific databases (PubMed, ScienceDirect, Web of Science, Academic Search Complete, and SPORTDiscus with Full Text via EBSCO) and the Internet to identify papers regarding recommendations for the PA intensity level for pregnant women. We analyzed 22 eligible guidelines, published over the last 10 years in English, from nine countries and three international organizations. Results: The PA of pregnant women should be at a moderate level. As for higher levels, the analyzed recommendations are contradictory. Methods for assessing PA intensity levels are often not included. The most frequently recommended methods for determining and assessing the PA intensity level for pregnant women are the rating of perceived exertion, the Talk Test, and heart rate measurements. Few guidelines offer specific advice for highly active women (e.g., elite athletes) or trimester-specific considerations. Conclusions: The number of published recommendations regarding PA during pregnancy has increased over the last decade. The amount of information on PA intensity levels is still insufficient. There is a need to update them, based on high-quality scientific work.

Physical activity promotion among pregnancy - the role of physician from the women's perspective

Objective

The clear benefits of planned and supervised physical activity (PA) during pregnancy make it imperative that women are encouraged and educated about this activity. This study aimed to investigate how effectively physician promote physical activity and exercise among pregnant women. It also examines pro-health changes in selected health behaviours during pregnancy.

Methods

This cross-sectional study recruited a total of 353 pregnant women in Wielkopolskie Voivodship in Poland. An anonymous survey (on-line or in-paper) was used to assess physical activity before and during pregnancy (with Pregnancy Physical Activity Questionnaire), physical activity self-efficacy, well-being (WHO-5 Well-Being Index), and guidance received from physicians on physical activity during pregnancy.

Results

Only 41% of women surveyed followed WHO recommendations for PA before pregnancy, and they were much more likely to discuss safety and the need to change the intensity or type of PA with their doctor or gynaecologist. Only 23% of women were asked about their PA before pregnancy and less than 40% were encouraged to be active during pregnancy. We observed a higher probability of poor well-being among pregnant women who were inactive before pregnancy (OR = 1.873, 95%CI 1.026 to 3.421, p = 0.041).

Conclusion

Health professionals infrequently educate and motivate women to be physically active during pregnancy. Physician advice, as it is currently perceived by women, seems to be insufficient to help pregnant women meet the recommendations for PA during pregnancy.

Physical activity during pregnancy and the risk of gestational diabetes mellitus: a systematic review and dose-response meta-analysis

BACKGROUND

Previous research has indicated the inverse association between physical activity (PA) and gestational diabetes mellitus (GDM). However, the dose-response relationship currently remains undetermined. This study aims to explore the dose-response relationship between PA during the first and second trimesters of pregnancy and GDM risk.

METHODS

Studies on the relationship between PA during pregnancy and GDM risk published before April 25, 2023, were searched for in six databases. According to the inclusion and exclusion criteria, all literature was screened for eligibility. The Newcastle-Ottawa Scale (NOS) was used to assess risk of bias. Publication bias was examined using funnel plots, Begg's and Egger's tests, as well as trim-and-fill analysis. We harmonized exposure estimates of PA during pregnancy to the common unit of the metabolic equivalent of task (MET)-h/week. Restricted cubic splines were used to model the dose-response relationship. The criteria from the World Cancer Research Fund were used to assess the certainty of evidence across outcomes. All analyses were performed using Stata 15.1.

RESULTS

The results indicated that in contrast with the lowest level of PA, promoting the highest PA level lowers the risk of GDM by 36% (RR = 0.64, 95%CI: 0.53 ~ 0.78). We found a curvilinear dose-response association between PA during the first trimester and incident GDM (Pnonlinearity = 0.012). Compared to inactive pregnant women, for those who achieved the guidelines-suggested minimum level (10 MET-h/week) of PA during the first trimester, the GDM risk was decreased by 13% (RR = 0.87, 95%CI: 0.79 ~ 0.96). A linear relationship was found between PA during the second trimester and the GDM risk (Pnonlinearity = 0.276). The results with a restricted cubic spline model suggested that pregnant women who accumulate 10 MET-h/week have a 1% reduced risk of GDM compared to completely inactive individuals. Twice (20 MET-h/week) or a higher amount of PA (50 MET-h/week) contributed to further reductions in GDM risk.

CONCLUSION

There is a dose-response relationship between higher levels of PA in both the first and second trimesters and reduced risk of GDM; the relationship is stronger in the first trimester. Increasing PA during pregnancy can prevent the development of GDM.

PROSPERO REGISTRATION NUMBER

CRD42023420564.

Effectiveness of group aerobic and/or resistance exercise programs associated with pelvic floor muscle training during prenatal care for the prevention and treatment of urinary incontinence: A systematic review

AIM

To evaluate the effectiveness of aerobic and/or resistance group exercise programs associated with pelvic floor muscle training (PFMT) during prenatal care for the prevention and treatment of urinary incontinence (UI) using the best level of evidence.

METHODS

A search was carried out in the MEDLINE/PubMed, LILACS, PEDro, CENTRAL, and SCOPUS databases, without restrictions. The terms "urinary incontinence" and "pregnant woman" were used. Randomized and quasi-randomized clinical trials were included using aerobic and/or resistance exercise programs plus PFMT as an intervention compared to usual care. The Cochrane tool (RoB 2.0) and GRADE were used to assess risk of bias and certainty of evidence, respectively. Quantitative analysis was assessed by meta-analyses.

RESULTS

Five publications were included. There was a reduction in the reports of UI postintervention at 16 weeks (RR: 0.83; 95% CI: 0.74-0.93, one study, 762 women, random effects: p = 0.002) and after 3 months (RR: 0.76; 95% CI: 0.60-0.95, one study, 722 women, random effects: p = 0.02), based on moderate certainty of evidence and improvement in UI-specific quality of life (MD: -2.42; 95% CI: -3.32 to -1.52, one study, 151 women, random effects: p < 0.00001), based on low quality of evidence. Other results showed no difference between the postintervention groups, with low and very low evidence.

CONCLUSION

There is moderate evidence that the aerobic and/or resistance exercise program associated with PFMT compared to usual care can reduce postintervention UI, as well as 3 months postintervention, and that it can improve UI-specific quality of life, but with low-evidence certainty.

Rehabilitation of anterior knee pain in the pregnant athlete: Considerations and modifications by trimester

BACKGROUND

Anterior knee pain is a common symptom many females experience during pregnancy. There are several musculoskeletal changes that occur in anatomy and physiology throughout the course of pregnancy that impact the lower extremity kinetic chain. Pregnant athletes, recreational through competitive, who attempt to maintain a high activity level through each trimester may be at increased risk for anterior knee pain due to a greater demand for lumbopelvic and hip stabilization.

CLINICAL QUESTION

What are the evidence-driven rehabilitation guidelines and specific modifications needed to treat anterior knee pain in the female athlete during each trimester of pregnancy?

KEY RESULTS

We aim to provide an overview of rehabilitation treatment guidelines for pregnant females with anterior knee pain, presenting specific physiological changes and rationale for modifications, discussed by trimester. We recommend our program be conducted under the supervision of a physical therapist working closely with the athlete's obstetrics and sports medicine team.

CLINICAL APPLICATION

The number of women who are active during pregnancy is increasing. We provide an overview of the guidelines and considerations for treating women with anterior knee pain during a healthy and uneventful pregnancy.

Physical activity and pregnancy outcomes: an expert review

This expert review aimed to assess current literature on the effect and tracking of physical activity during pregnancy and associated outcomes. Self-reported physical activity may be inaccurate given the subjective nature of the questionnaires. The accelerometer ActiGraph is considered the "gold standard" to objectively measure physical activity. However, other more user-friendly wearable devices are now widely available and may accurately track physical activity. Conclusive data from both validated activity questionnaires and accelerometers indicate that physical activity is safe during pregnancy. In addition, studies of physical activity during pregnancy that evaluate pregnancy outcomes have found reduced risks of preterm birth, preeclampsia, and gestational diabetes mellitus and improved mental health among individuals who regularly engage in physical activity. In the United States, approximately 48% of pregnant individuals gain more than the recommended amount of weight during pregnancy; excessive gestational weight gain is associated with an increased risk of maternal and fetal complications, including preterm birth, preeclampsia, and gestational diabetes mellitus, and corresponding higher adverse short- and long-term maternal and offspring health outcomes. Although physical activity is safe during pregnancy and may reduce excessive gestational weight gain and resultant pregnancy complications, further research is needed to determine the frequency and duration of specific types of physical activity during pregnancy. Providers should encourage physical activity before and during pregnancy and educate patients regarding the benefits and safety of physical activity.

Current Research Trends, Hotspots, and Frontiers of Physical Activity during Pregnancy: A Bibliometric Analysis

PURPOSE

Physical activity (PA) during pregnancy has been proven beneficial to pregnant women, with a significant effect on ameliorating many severe gestational complications. This work aimed to reveal current research trends, hotspots, and future frontiers in PA during pregnancy.

METHODS

Software CiteSpace was used to perform a bibliometric analysis with 1415 publications in the Web of Science Core Collection.

RESULTS

the number of published papers on PA during pregnancy has increased gradually by year. The United States has made the most significant contribution to the research on this topic, ranking first in the world in both the number and centrality of research. A total of 54 articles (3.8%) were published in 2022. A majority of publications were research articles (n = 1176, 78.9%). The authors and institutions of the research published have more inter-country collaborations. Different patterns of PA, prevention, and amelioration of pregnancy complications are major research hotspots. Improvement of sedentary behaviour, lifestyle intervention through leisure-time PA, and preterm care are major research frontiers and have received extensive attention in recent years.

CONCLUSIONS

The current scientometric study presents an overview of PA during pregnancy research conducted throughout the preceding decades. The conclusions of this work might serve as a reference for researchers who are interested in this field.

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.

A Web-Based mHealth Intervention With Telephone Support to Increase Physical Activity Among Pregnant Patients With Overweight or Obesity: Feasibility Randomized Controlled Trial

BACKGROUND

Pregnant patients with overweight or obesity are at high risk for perinatal complications. Excess gestational weight gain (GWG) further exacerbates this risk. Mobile health (mHealth) lifestyle interventions that leverage technology to facilitate self-monitoring and provide just-in-time feedback may motivate behavior change to reduce excess GWG, reduce intervention costs, and increase scalability by improving access.

OBJECTIVE

This study aimed to test the acceptability and feasibility of a pilot mHealth lifestyle intervention for pregnant patients with overweight or obesity to promote moderate intensity physical activity (PA), encourage guideline-concordant GWG, and inform the design of a larger pragmatic cluster randomized controlled trial.

METHODS

We conducted a mixed methods acceptability and feasibility randomized controlled trial among pregnant patients with a prepregnancy BMI of 25 to 40 kg/m2. Patients with singletons at 8 to 15 weeks of gestation who were aged ≥21 years and had Wi-Fi access were recruited via email from 2 clinics within Kaiser Permanente Northern California and randomized to receive usual prenatal care or an mHealth lifestyle intervention. Participants in the intervention arm received wireless scales, access to an intervention website, activity trackers to receive automated feedback on weight gain and activity goals, and monthly calls from a lifestyle coach. Surveys and focus groups with intervention participants assessed intervention satisfaction and ways to improve the intervention. PA outcomes were self-assessed using the Pregnancy Physical Activity Questionnaire, and GWG was assessed using electronic health record data for both arms.

RESULTS

Overall, 33 patients were randomly assigned to the intervention arm, and 35 patients were randomly assigned to the usual care arm. All participants in the intervention arm weighed themselves at least once a week, compared with 20% (7/35) of the participants in the usual care arm. Participants in the intervention arm wore the activity tracker 6.4 days per week and weighed themselves 5.3 times per week, and 88% (29/33) of them rated the program "good to excellent." Focus groups found that participants desired more nutrition-related support to help them manage GWG and would have preferred an app instead of a website. Participants in the intervention arm had a 23.46 metabolic equivalent of task hours greater change in total PA per week and a 247.2-minute greater change in moderate intensity PA per week in unadjusted models, but these effects were attenuated in adjusted models (change in total PA: 15.55 metabolic equivalent of task hours per week; change in moderate intensity PA: 199.6 minutes per week). We found no difference in total GWG (mean difference 1.14 kg) compared with usual care.

CONCLUSIONS

The pilot mHealth lifestyle intervention was feasible, highly acceptable, and promoted self-monitoring. Refined interventions are needed to effectively affect PA and GWG among pregnant patients with overweight or obesity.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03936283; https://clinicaltrials.gov/ct2/show/NCT03936283.

Maternal Exercise Before and During Pregnancy Facilitates Embryonic Myogenesis by Enhancing Thyroid Hormone Signaling

Background: Maternal exercise (ME) improves fetal and offspring muscle development, but mechanisms remain to be established. Since the thyroid hormone (TH) is critical for cell differentiation during embryonic development, we hypothesized that ME elevates TH receptor (THR) signaling in embryos, which promotes embryonic myogenesis. Methods: Female mice were exercised daily on a treadmill or received a daily TH, triiodothyronine (T3) injection. Embryos (embryonic day 12.5 [E12.5]) and P19 cells were used for studying effects of TH on embryonic myogenesis. TH levels in serum and embryos after ME or T3I were analyzed. Expression of TH signaling related genes and myogenic genes was assessed. THRα binding to the promoters of myogenic genes was investigated by chromatin immunoprecipitation-qantitative polymerase chain reaction (ChIP-qPCR). A CRISPR/CAS9 plasmid was utilized to knock out THRα in P19 cells. Results: ME elevated TH levels in both maternal circulation and embryos, which were correlated with enhanced TH signaling and myogenesis. At E12.5, both myogenic determinants (Pax3, Pax7) and myogenic regulatory factors (Myf5, Myod) were upregulated in ME embryos. ME increased THRα content and elevated messenger RNA (mRNA) expression of TH transporter Slc16a2 and deiodinase Dio2. In addition, the THRα binding to the promoters of Pax3/7 was increased. In P19 embryoid bodies, T3 promoted myogenic differentiation, which was abolished by ablating THRα. Furthermore, maternal daily injection of T3 at a level matching exercised mothers promoted embryonic myogenesis. Conclusions: ME promotes TH delivery to the embryos and enhances embryonic myogenesis, which is partially mediated by enhanced TH signaling in ME embryos.

Monitoring Physical Activity Intensity During Pregnancy

For apparently healthy pregnant women, regular physical activity is recommended. The American College of Obstetricians and Gynecologists (ACOG) created recommendations for physical activity and exercise during pregnancy in 1985. At that time, pregnant women were advised to not exceed a heart rate of 140 beats per minute with physical activity. The heart rate recommendation was subsequently removed with the recommendations published in 1994, 2002, and 2015. In 2020, the ACOG updated its recommendations on physical activity for pregnant and postpartum women. The recommendation included exercising at a "fairly light to somewhat hard" perceived intensity and at less than 60-80% of age-predicted maximum heart rate, usually not exceeding a heart rate of 140 beats per minute. Women often seek advice from healthcare providers on physical activity during pregnancy, yet providers report concern about giving appropriate physical activity guidance. This paper summarizes the key scientific literature on monitoring absolute and relative exercise intensity in relation to the current ACOG recommendations, providing background on intensity-related concepts used in the recommendation. This paper also provides practical guidance to assist healthcare providers in relaying this information to pregnant women.

Perception and Feelings of Antenatal Women during COVID-19 Pandemic: A Cross-Sectional Survey

Introduction: To assess the level of anxiety and knowledge regarding COVID-19 amongst antenatal women. Materials and Methods: This cross-sectional survey was conducted in the antenatal clinics of KK Women’s and Children’s Hospital, Singapore, from 31 March to 25 April 2020 to assess pregnant women’s knowledge of COVID-19, their perceptions of its impact upon pregnancy and psychological impact using the validated Depression, Anxiety, and Stress Scales (DASS-21). Results: Of the 324 women who participated in the study, the mean age was 31.8 years (range, 20–45). The majority (53.7%) were multiparous with mean gestational age of 23.4 weeks (SD 10). The commonest sources of information were Internet-based social media platforms. A significant proportion were unaware, or associated COVID-19 infection during pregnancy with fetal distress (82.1%), intrauterine death (71.3%), fetal anomalies (69.8%), miscarriages (64.8%), preterm labour (67.9%) and rupture of membranes (61.4%). A total of 116 (35.8%) women screened positive for anxiety, 59 (18.2%) for depression, and 36 (11.1%) for stress. There was a significant association between household size and stress scores [B = 0.0454 (95% CI, 0.0035–0.0873)]. Women who associated COVID-19 infection with fetal anomalies and intrauterine fetal death had significantly higher anxiety scores [B = −0.395 (95% CI, −0.660 to −0.130) and B = −0.291 (95% CI, −0.562 to −0.021) respectively]. Conclusion: Our study highlights that a lack of timely and reliable information on the impact of COVID-19 on pregnancy and its outcomes results in increased levels of depression, anxiety and stress. The healthcare provider must address these issues urgently by providing evidence-based information using Internet-based resources and psychological support. Key words: Depression, Anxiety, Stress, Pregnancy, Knowledge

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

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

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

Importance

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

Objective

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

Evidence Acquisition

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

Results

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

Conclusions and Relevance

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

Assessment of endpoint criteria and perceived barriers during maximal cardiorespiratory fitness testing among pregnant women

BACKGROUND

A plateau in volume of oxygen consumption (VO2) is the primary indicator for determining if an individual has reached their maximal aerobic capacity. However, secondary criteria can also be used to identify maximal effort (i.e. lactate level, rating of perceived exertion [RPE], percent of age-predicted maximal heart rate [HR] and respiratory exchange ratio [RER]). Age and gender-specific secondary criteria have been developed for the general population, but no secondary criteria have been established for pregnant women. The primary purpose of this study was to analyze secondary endpoint criteria during VO2max testing among pregnant women. A secondary purpose was to identify emotional and physical barriers pregnant women have that may prevent them from reaching maximal effort.

METHODS

Twenty-five pregnant women (age= 30.0±3.6 years; gestation age= 22.1±1.4 weeks, pre-pregnancy BMI= 23.68±4.04 kg/m2) participated. Each participant completed a Bruce protocol treadmill test and maximal HR, RER, lactate, and RPE were assessed and compared to standards. Barriers were assessed immediately postexercise via open-ended questions.

RESULTS

The mean VO2max was 32.9±8.8 mL/kg/min. Mean RPEmax was 17.6±1.8 versus the standard of RPE≥17 (P=0.12). Percent of age-predicted HRmax was 88.0±6.8% versus the standard of ≥95% (P<0.001). Immediate postexercise lactate was 6.8±2.4mM versus the standard of ≥8 mM (P=0.03). Maximal RER was 1.2±0.2 versus the standard of RERmax ≥1.1 (P=0.08).

CONCLUSIONS

Our data provide preliminary evidence that secondary criteria may need to be adjusted for pregnant women. Additionally, physical and emotional barriers may be enhanced by pregnancy (e.g. pain, discomfort, anxiety, health concerns), and may limit the performance of pregnant women during maximal exercise.

[Should physical activity be contraindicated during pregnancy in relation to its potentially related risks?]

OBJECTIVE

This paper aimed at providing a critical analysis of data on the risks associated with physical activity of women during their pregnancy.

METHODS

Cochrane Library, Google Scholar, PubMed (Medline) and Web of Sciences were searched using a combination of MeSH terms associated to "Physical activity", "Pregnancy" and "Adverse events" or "Risks". Only review papers published from inception of these databases to November 2016 were used in the present analysis.

RESULTS

The electronic search yield a total of 104 citations. After a critical analysis of abstracts and/or full-texts, only a systematic review and cohort study on injuries related to physical activity during pregnancy appeared relevant for the current study. Data reveals a very small proportion (<1 %) of adverse events in direct link with the physical activity behavior of pregnant women. Furthermore, there would be less than one serious adverse event per 5000hours of physical activity. The only serious adverse event attributable to physical activity during pregnancy was uterine contractions. The threat of preterm labor and miscarriage risk cannot be primarily attributed to the participation of pregnant women in a physical activity, even vigorous. Moreover, no adverse effects of maternal physical activity on neonatal outcomes were found.

CONCLUSION

Physical activity-related risks during pregnancy appear to be infrequent and of minor severity. Though further studies are required to better understand the risk/benefit balance of physical activity during pregnancy, current data do not support the contraindication of this behavior in pregnant women.

Exercise and pregnancy in recreational and elite athletes: 2016 evidence summary from the IOC expert group meeting, Lausanne. Part 2-the effect of exercise on the fetus, labour and birth

This is Part 2 of 5 in the series of evidence statements from the IOC expert committee on exercise and pregnancy in recreational and elite athletes. Part 1 focused on the effects of training during pregnancy and on the management of common pregnancy-related symptoms experienced by athletes. In Part 2, we focus on maternal and fetal perinatal outcomes.

Educational intervention regarding diet and physical activity for pregnant women: changes in knowledge and practices among health professionals

BACKGROUND

The knowledge and practices of health professionals have a recognized role in behaviors related to the health of their patients. During pregnancy, this influence can be even stronger because there is frequent contact between women and doctors/nurses at periodic antenatal visits. When trained, supported and motivated, these professionals can act as health promoters. This study aimed to evaluate the effect of a focused educational intervention on improving the knowledge and practices of health professionals concerning diet and physical activity during pregnancy.

METHODS

A controlled, non-randomized study was performed to assess the effects of an educational intervention on the knowledge and practices of nurses and doctors who provide primary care to pregnant women. The intervention group, doctors and nurses (n = 22) from the family health units in a medium-sized city of São Paulo State, Brazil, received 16 h of training comprising an introductory course and three workshops, whereas the control group, doctors and nurses (n = 20) from traditional basic health units in Botucatu, did not. The professionals' knowledge was assessed at two time points, 1 month prior to and 1 year after the beginning of the intervention, using an ad hoc self-report questionnaire. The increases in the knowledge scores for walking and healthy eating of the intervention and control groups were calculated and compared using Student's t-test. To analyze the professionals' practice, women in the second trimester of pregnancy were asked whether they received guidance on healthy eating and leisure-time walking; 140 of these women were cared for by professionals in the intervention group, and 141 were cared for by professionals in the control group. The percentage of pregnant women in each group that received guidance was compared using the chi-square test and the Prevalence Ratio (PR), and the corresponding 95 % confidence intervals (CI) were calculated.

RESULTS

The intervention improved the professionals' knowledge regarding leisure-time walking (92 % increase in the score, p < 0.001). The women who were cared for by the intervention group were more likely to receive guidance regarding leisure-time walking (PR = 2.65; 95 % CI = 1.82-3.83) and healthy eating (PR = 1.76; 95 % CI = 1.34-2.31) when compared to the control group.

CONCLUSION

It is possible to improve the knowledge and practices of health professionals through the proposed intervention aimed at primary health care teams providing antenatal care.

Physical exercise during pregnancy and its influence in the type of birth

OBJECTIVE

To verify if medium intensity exercise performed during pregnancy can influence in the type of delivery, and to observe compliance to an exercise program among primiparous women with different levels of schooling.

METHODS

A study carried out at the Centro de Incentivo ao Aleitamento Materno, in São Sebastiao (SP), between April 7, 2008, and April 14, 2009. A prospective study involving 66 primiparous women who were divided into two groups: an Exercise Group, engaged in regular physical activity during pregnancy, and the Control Group, that did not participate in regular physical activity during the same period. Significance level in this project was 5% (p = 0.05).

RESULTS

The group that did engage in regular exercise had a higher rate of vaginal deliveries, with a statistically significance difference evaluated by the χ² test (p = 0.031). The pregnant women with the highest level of schooling showed greater compliance with the exercise program, with a statistically significant difference (p = 0.01736).

CONCLUSION

Physical exercise in primiparous women increased the chances of vaginal deliveries, and there was greater compliance with the exercise program among those with a higher level of schooling when compared to those with a basic education.

Guidelines for Physical Activity during Pregnancy: Comparisons From Around the World

INTRODUCTION

Women attain numerous benefits from physical activity during pregnancy. However, due to physical changes that occur during pregnancy, special precautions are also needed. This review summarizes current guidelines for physical activity among pregnant women worldwide.

METHODS

We searched PubMed (MedLINE) for country-specific governmental and clinical guidelines on physical activity during pregnancy through the year 2012. We cross-referenced with articles referring to guidelines, with only the most recent included. An abstraction form was used to extract key details and summarize.

RESULTS

In total, 11 guidelines were identified from nine countries (Australia, Canada, Denmark, France, Japan, Norway, Spain, United Kingdom, United States). Most guidelines supported moderate intensity physical activity during pregnancy (10/11) and indicated specific frequency (9/11) and duration/time (9/11) recommendations. Most guidelines provided advice on initiating an exercise program during pregnancy (10/11). Six guidelines included absolute and relative contraindications to exercise. All guidelines generally ruled-out sports with risks of falls, trauma, or collisions. Six guidelines included indications for stopping exercise during pregnancy.

CONCLUSION

This review contrasted pregnancy-related physical activity guidelines from around the world, and can help to inform new guidelines as they are created or updated, and facilitate the development of a worldwide guideline.

A qualitative study of women's perceptions of provider advice about diet and physical activity during pregnancy

OBJECTIVE

The purpose of this qualitative study was to gather insights into pregnant women's experiences with provider advice about diet and physical activity.

METHODS

We conducted a series of 13 focus groups with a total of 58 pregnant African American, Caucasian, and Hispanic women of varying body sizes. Statements were independently coded, reduced, and then reconstructed to identify overarching themes with the assistance of ATLAS/ti software.

RESULTS

Mean gestational age at the time of the focus groups was 30 weeks. Women commonly reported overwhelming and confusing diet advice and a paucity of physical activity advice that was largely limited to walking. Many reported following advice; when advice was not followed, it was because women disagreed with it or simply did not want to do it.

CONCLUSION

Women would benefit from more clear guidance from physicians and other providers regarding dietary choices and physical activity in pregnancy.

PRACTICE IMPLICATIONS

Providers should make dietary and physical activity advice in pregnancy more clear and individualized and offer such guidance multiple times throughout pregnancy.

Physical activity during pregnancy: impact of applying different physical activity guidelines

Multiple guidelines and definitions of physical activity (PA) have been used to study the benefits of activity during pregnancy. The different guidelines lead to a wide range of prevalence estimates and this has led to conflicting reports about activity patterns during pregnancy. A longitudinal study was conducted to assess PA using a pattern-recognition monitor for a 7-day period at week 18 (n = 55) and week 35 (n = 66) of pregnancy. The amount of activity performed and the number of women meeting six different PA guidelines were evaluated. Adherence to PA guidelines ranged from 5 to 100% and 9 to 100% at weeks 18 and 35, respectively. All women achieved the 500 MET-minute guideline and nearly all women accumulated ≥150 minutes of weekly moderate-vigorous physical activity (MVPA) at both time points. Only 22% and 26% participated in ≥3 sessions of MVPA lasting ≥30 minutes at both time points and this further declined to 5% and 9% when the guideline was increased to ≥5 sessions of 30 minutes. The amount of PA during pregnancy varied drastically depending on which guideline was used. Further research is warranted to clearly identify the patterns of activity that are associated with healthy pregnancy outcomes.

Physical activity and pregnancy: past and present evidence and future recommendations

PURPOSE

In this review, we provide researchers and practitioners with an overview of the physical activity and pregnancy literature to promote prenatal physical activity, improve measurement, further elucidate the role of activity in reducing maternal health complications, and inform future research.

METHOD

We examined past and present physical activity and pregnancy studies and highlight key papers with a focus on maternal health outcomes to best inform physical activity promotion efforts.

RESULTS

We discuss: (a) historical overview of prenatal physical activity relative to the physical activity guidelines, how they have changed over time, and how evidence of the effect of prenatal activity on maternal/fetal health outcomes has affected clinical recommendations; (b) existing tools and challenges associated with measuring prenatal physical activity; (c) empirical evidence on multilevel determinants of prenatal activity to guide future intervention work; (d) empirical evidence of prenatal activity on adverse maternal outcomes (gestational diabetes mellitus, preeclampsia, excessive gestational weight gain) from observational and intervention studies; and (e) summary/recommendations for future research and practice.

CONCLUSIONS

The physical activity and pregnancy literature has evolved over the past 50 years, and there is sufficient empirical evidence to support the promotion of moderate-to-vigorous prenatal physical activity for maternal health benefits. Future studies and interventions should be carefully designed, theoretically driven, and include validated and reliable activity measures. Researchers and practitioners should also consider the multifaceted determinants and outcomes of prenatal physical activity and intervene to promote physical activity before, during, and after pregnancy.

Exercise and pregnancy knowledge among healthcare providers

AIM

To examine healthcare provider knowledge, beliefs, and practices regarding exercise during pregnancy using a cross-sectional 31-question pen and paper survey.

METHODS

Ninety-three practicing healthcare providers, M.D. (n = 45) and D.O. (n = 14) physicians and certified nurse midwives (C.N.M., n = 34), from hospitals and birth centers around Michigan participated in this study. Descriptive characteristic data, provider knowledge, beliefs, and practices regarding exercise during pregnancy, common exercise restrictions given to pregnant patients, and provider awareness of current American College of Obstetricians and Gynecologists (ACOG) exercise and pregnancy guidelines were collected. Descriptive statistics and chi-square analyses were completed.

RESULTS

Overall, 99% of respondents believed that exercise during pregnancy is beneficial, 64% of all respondents believed that maternal exercise heart rate should not exceed 140 beats per minute (bpm), and 60% of M.D.s and 86% of D.O.s were not familiar with the 1994 ACOG guidelines for exercise and pregnancy (p < 0.05).

CONCLUSIONS

Although the providers' beliefs about exercise during pregnancy were positive, not all were aware of or followed current ACOG recommendations. Different strategies for dissemination of current research may be warranted.

Exercise during pregnancy: fetal responses to current public health guidelines

OBJECTIVE

To evaluate acute fetal responses to individually prescribed exercise according to existing guidelines (U.S. Department of Health and Human Services) in active and inactive pregnant women.

METHODS

Forty-five healthy pregnant women (15 nonexercisers, 15 regularly active, 15 highly active) were tested between 28 0/7 and 32 6/7 weeks of gestation. After a treadmill test to volitional fatigue, target heart rates were calculated for two subsequent 30-minute treadmill sessions: 1) moderate intensity (40-59% heart rate reserve); and 2) vigorous intensity (60-84%). All women performed the moderate test; only active women performed the vigorous test. Fetal well-being measures included umbilical artery Dopplers, fetal heart tracing and rate, and biophysical profile. Measures were obtained at rest and immediately postexercise.

RESULTS

Groups were similar in age, body mass index, and gestational age. Maternal resting heart rate in the highly active group (61.6 ± 7.2 beats per minute [bpm]) was significantly lower than the nonexercise (79.0 ± 11.6 bpm) and regularly active (71.9 ± 7.4 bpm) groups (P<.001). Treadmill time was longer in highly active (22.3 ± 2.9 minutes) than regularly active (16.6 ± 3.4) and nonexercise (12.1 ± 3.6) groups (P<.001), reflecting higher fitness. With moderate exercise, all umbilical artery Doppler indices were similar pre-exercise and postexercise among groups. With vigorous exercise, Dopplers were similar in regularly and highly active women with statistically significant decreases postexercise (P<.05). The group × time interaction was not significant. Postexercise fetal heart tracings met criteria for reactivity within 20 minutes after all tests. Biophysical profile scores were reassuring.

CONCLUSION

This study supports existing guidelines indicating pregnant women may begin or maintain an exercise program at moderate (inactive) or vigorous (active) intensities.

A pregnancy and postpartum lifestyle intervention in women with gestational diabetes mellitus reduces diabetes risk factors: a feasibility randomized control trial

OBJECTIVE

To pilot, among women with gestational diabetes mellitus (GDM), the feasibility of a prenatal/postpartum intervention to modify diet and physical activity similar to the Diabetes Prevention Program. The intervention was delivered by telephone, and support for breastfeeding was addressed.

RESEARCH DESIGN AND METHODS

The goal was to help women return to their prepregnancy weight, if it was normal, or achieve a 5% reduction from prepregnancy weight if overweight. Eligible participants were identified shortly after a GDM diagnosis; 83.8% consented to be randomly assigned to intervention or usual medical care (96 and 101 women, respectively). The retention was 85.2% at 12 months postpartum.

RESULTS

The proportion of women who reached the postpartum weight goal was higher, although not statistically significant, in the intervention condition than among usual care (37.5 vs. 21.4%, absolute difference 16.1%, P=0.07). The intervention was more effective among women who did not exceed the recommended gestational weight gain (difference in the proportion of women meeting the weight goals: 22.5%, P=0.04). The intervention condition decreased dietary fat intake more than the usual care (condition difference in the mean change in percent of calories from fat: -3.6%, P=0.002) and increased breastfeeding, although not significantly (condition difference in proportion: 15.0%, P=0.09). No differences in postpartum physical activity were observed between conditions.

CONCLUSIONS

This study suggests that a lifestyle intervention that starts during pregnancy and continues postpartum is feasible and may prevent pregnancy weight retention and help overweight women lose weight. Strategies to help postpartum women overcome barriers to increasing physical activity are needed.

Evidence-based risk assessment and recommendations for physical activity clearance: pregnancy1This paper is one of a selection of papers published in this Special Issue, entitled Evidence-based risk assessment and recommendations for physical activity clearance, and has undergone the Journal’s usual peer review process

Recommendations for physical activity during pregnancy have progressed significantly in the last 30 years and continue to evolve as an increasing body of scientific evidence becomes available. In addition, there is an increasing number of women who wish to either maintain physical fitness levels during the prenatal period or initiate exercise for a healthier lifestyle during pregnancy. As such, consistent evaluation of the risks associated with exercise during pregnancy is warranted for maternal and fetal well-being. The primary purpose of this systematic review was to evaluate the scientific information available regarding maternal and fetal responses as it relates to the occurrence of adverse exercise-related events in pregnant women without contraindications to exercise. A systematic and evidence-based approach was used to analyze critically the level of evidence for risks associated with acute and chronic exercise during pregnancy in healthy pregnant women. All articles were screened according to standardized evaluation criteria developed by a panel of experts. A total of 74 investigations that involved 3766 pregnant women were included in the analysis. Of the 74 studies, only 35 studies documented the presence or absence of adverse events. The serious adverse event rate for these studies was 1.4 per 10 000 h of exercise. The adverse event rate increased to 6.8 per 10 000 h of exercise when including the occurrence of more mild events and exercise-related fetal bradycardia and tachycardia. Previously inactive or active women (without contraindications) are at a low risk for adverse fetal or maternal events if they participate in routine physical activity during pregnancy.

Fetal cardiotocography before and after water aerobics during pregnancy

OBJECTIVE

To evaluate the effect of moderate aerobic physical activity in water on fetal cardiotocography patterns in sedentary pregnant women.

METHOD

In a non-randomized controlled trial, 133 previously sedentary pregnant women participated in multiple regular sessions of water aerobics in a heated swimming pool. Cardiotocography was performed for 20 minutes before and just after the oriented exercise. Cardiotocography patterns were analyzed pre- and post-exercise according to gestational age groups (24-27, 28-31, 32-35 and 36-40 weeks). Student's t and Wilcoxon, and McNemar tests were used, respectively, to analyze numerical and categorical variables.

RESULTS

No significant variations were found between pre- and post-exercise values of fetal heart rate (FHR), number of fetal body movements (FM) or accelerations (A), FM/A ratio or the presence of decelerations. Variability in FHR was significantly higher following exercise only in pregnancies of 24-27 weeks.

CONCLUSIONS

Moderate physical activity in water was not associated with any significant alterations in fetal cardiotocography patterns, which suggests no adverse effect on the fetus.

Beliefs about exercise and physical activity among pregnant women

OBJECTIVE

The objective of this study was to document self-reported beliefs about physical activity and exercise among pregnant women.

METHODS

The Pregnancy, Infection, and Nutrition (PIN3) Study asked 1306 pregnant women about beliefs regarding physical activity and exercise at 27-30 weeks' gestation.

RESULTS

While 78% of women agreed that most women can continue their regular exercise during pregnancy, fewer (68%) agreed that most women who never exercised could begin an exercise program during pregnancy. Most (89%) agreed that regular exercise was better than irregular exercise during pregnancy. While almost all women agreed with the benefits of light activity (98%), fewer agreed that there were benefits with moderate (73%) or vigorous exercise (13%). Differences in beliefs were most notable by educational level, race/ethnicity, and whether they participated in regular exercise during pregnancy.

CONCLUSION

Future studies can better elucidate the reasons behind the differences in beliefs, to explore whether cultural reasons are contributing to these differences and whether tailored messages would be more effective than general educational approaches.

PRACTICE IMPLICATIONS

This study provides information to create more successful interventions to help women understand concepts regarding the safety and benefits of physical activity during pregnancy.

The Effect of Exercise During Pregnancy on Maternal Outcomes: Practical Implications for Practice

The American College of Obstetricians and Gynecologists recommends that women with low-risk pregnancies participate in moderate-intensity exercise during their pregnancy. Currently, only 15.1% of pregnant women exercise at the recommended levels, which is significantly lower than the general population's 45%. One potential reason is that exercise during pregnancy is perceived as risky. In this article, the authors provide a critical review of the literature examining the effect of exercise on preeclampsia, gestational diabetes, weight gain, labor and birth, and other issues associated with pregnancy. Overall, the evidence indicates that exercise during pregnancy is safe and perhaps even reduces the risk of preeclampsia and gestational diabetes. The evidence for weight gain and labor and birth (rates of cesarean sections, duration of labor) is mixed. Unfortunately, much of the research examining exercise during pregnancy is observational, and the few randomized controlled trials that do exist are small and inadequately powered. Taken together, given the potential benefits of exercise during pregnancy and the lack of evidence for harmful effects on the mother and newborn, practitioners should encourage their healthy pregnant patients to exercise. Practical guidelines for recommending exercise to pregnant women are presented.

Maternal physiological responses to swimming training during the second trimester of pregnancy

Maternal submaximal aerobic fitness (PWC170) was measured before, during, and after 12 weeks of swimming training during the second trimester of pregnancy in 23 sedentary women. For comparison, 11 women maintained their normal activities, but did not swim. Training sessions were 3 times per week for 40 min, producing heart rate (HR) responses of 65%-70% of estimated maximum HR and increases in rectal temperature (n = 8) of approximately 0.4 degrees C. Distance swum per session almost doubled over the training period (581 +/- 177 m to 1110 +/- 263 m). PWC170 of the nonswimming group remained stable over time; that of the swimming group increased significantly by 13.8% after 8 weeks of training (790 +/- 145 to 909 +/- 137 kpm/min; p = 0.026). The results indicate that a significant aerobic training effect can be achieved by light-moderate-intensity swimming during pregnancy in previously sedentary women. Further, all women remained healthy, with no adverse outcomes for mother or baby.

Water Aerobics Reduces Sick Leave due to Low Back Pain During Pregnancy

OBJECTIVE

To compare the effect of a land-based, physical exercise program versus water aerobics on low back or pelvic pain and sick leave during pregnancy.

DESIGN

Randomized controlled clinical trial.

SETTING

Three antenatal care centers.

PARTICIPANTS

390 healthy pregnant women.

INTERVENTIONS

A land-based physical exercise program or water aerobic once a week during pregnancy.

MAIN OUTCOME MEASURES

Sick leave, pregnancy-related low back pain or pregnancy-related pelvic girdle pain, or both.

RESULTS

Water aerobics diminished pregnancy-related low back pain (p=.04) and sick leave due to pregnancy-related low back pain (p=.03) more than a land-based physical exercise program.

CONCLUSIONS

Water aerobics can be recommended for the treatment of low back pain during pregnancy. The benefits of a land-based physical exercise program are questionable and further evaluation is needed.

Low-impact exercise during pregnancy - a study of safety

BACKGROUND

Exercise is an important part of many women's lives. Women are often advised to refrain from physical exercise during pregnancy. The reason given is mainly safety, i.e. fear of maternal hyperthermia, which is known to be related to neural tube defects. However, exercise during pregnancy has not been shown to be related to hyperthermia.

OBJECTIVE

To study temperature and oxygen saturation responses to low-impact exercise in healthy pregnant women.

METHODS

Forty pregnant women and 11 controls participating in low-impact aerobic exercise were monitored before exercise, at maximum-exercise level, and after exercise with regard to core temperature, heart rate, and oxygen saturation level.

RESULTS

The core temperature among the pregnant women did not increase significantly at maximum exercise or after exercise (36.5 versus 36.7 or 36.5 degrees C, P = 0.1, P = 0.5). None of the pregnant women were even close to approaching a dangerous body temperature at an intensity level of 69% of their maximum heart rate. As compared with pre-exercise values, oxygen saturation among pregnant women was significantly reduced at both maximum-exercise and postexercise measurements, but no measurement was below 95% in oxygen saturation.

CONCLUSION

Low-impact aerobics at about 70% of one's maximum heart rate appears to be safe in terms of risk of maternal hyperthermia.

Vigorous leisure activity and pregnancy outcome

BACKGROUND

Preterm birth is the leading cause of perinatal mortality in North America and Europe and a major predictor of neonatal and infant morbidity. Postterm birth is associated with increased infant mortality and morbidity, as well as increased frequency of surgical or induced labor. Because vigorous leisure activity may affect timing of delivery, this study examined association between vigorous leisure activity and birth outcomes.

METHODS

Women (N = 1,699) with a singleton pregnancy were recruited at 24-29 weeks' gestation from prenatal clinics in central North Carolina between 1995 and 1998. The type and duration of any regular vigorous leisure activity was assessed in a telephone interview covering the 3-month period before pregnancy and during the first and second trimesters of pregnancy.

RESULTS

The prevalence of vigorous leisure activity was 22% before pregnancy, 14% during the first trimester, and 8% during the second trimester. Vigorous leisure activity before pregnancy was unrelated to preterm (<37 weeks) as compared with term delivery (37 to <42 weeks). The risk of preterm birth was somewhat reduced with vigorous leisure activity during the first trimester (odds ratio = 0.80; 95% confidence interval = 0.48-1.35) and more so during the second trimester (odds ratio = 0.52; 95% confidence interval = 0.24-1.11). Vigorous leisure activity before pregnancy or during the first or second trimester was not associated with postterm delivery (>/=42 weeks).

CONCLUSIONS

Vigorous leisure activity during the first trimester, and even more so in the second trimester, was associated with a reduced risk of preterm birth. There was no association with postterm birth. To address the etiologic role of activity on pregnancy outcome and to overcome self-selection, a randomized clinical trial would be needed.

Effect of postpartum exercise on mothers and their offspring: a review of the literature

Epidemiological studies suggest that childbearing may contribute to the development of obesity. In the past 12 years, several cross-sectional and randomized trials have addressed the effect of postpartum exercise on weight loss and/or energy balance in mostly lactating women. These studies suggest that moderate exercise without specific calorie restriction does not promote greater weight or fat loss. This may be because exercise may promote greater energy intake and/or reduced energy expenditure from nonexercise physical activity (thus preventing negative energy balance), but further research is needed. Regular exercise, however, is likely to have other important health benefits after childbirth. A few published studies suggest that postpartum exercise improves aerobic fitness, high-density lipoprotein-cholesterol levels, and insulin sensitivity. Exercise may also enhance psychological well-being, but controlled clinical studies are needed. Although two published studies have addressed whether exercise training attenuates lactation-induced bone loss, better controlled studies are needed to determine whether postpartum weight-bearing exercise can improve bone mineral density in lactating and nonlactating women alike. In lactating women, several studies have collectively determined that neither acute nor regular exercise has adverse effects on a mother's ability to successfully breast-feed. It needs to be determined whether a woman's participation in regular exercise after childbirth will improve her ability to mother or instill lifetime habits of regular physical activity in either herself or her offspring. Overall, published studies have established the importance of regular exercise during the postpartum period. More research, however, is needed in this important area.

SMA statement the benefits and risks of exercise during pregnancy. Sport Medicine Australia

There are numerous benefits to pregnant women of remaining active during pregnancy. These include improved weight control and maintenance of fitness. There may also be benefits in terms of reduced risk of development of gestational diabetes meilitus and improved psychological functioning. Moderate intensity aerobic exercise has been shown to be safe in pregnancy, with a number of studies now indicating that for trained athletes it may be possible to exercise at a higher level than is currently recommended by the American College of Obstetricians and Gynecologists. Studies of resistance training, incorporating moderate weights and avoiding maximal isometnc contractions, have shown no adverse outcomes. There may be benefits of increased strength and flexibility. The risk of neural tube defects due to exercise-induced hyperthermia that is suggested by animal studies is less likely in women, because of more effective mechanisms of heat dissipation in humans. There is accumulating evidence to suggest that participation in moderate intensity exercise throughout pregnancy may enhance birth weight, while more severe or frequent exercise, maintained for longer into the pregnancy: may result in lighter babies. There have been no reports of foetal injury or death in relation to trauma or contact during sporting activities. Despite this, a risk of severe blunt trauma is present in some sporting situations as pregnancy progresses. Exercise and lactation are compatible in the post-partum period, providing adequate calories are consumed. Considerations of pelvic floor function and type of delivery are relevant in planning a return to certain types of exercise at this time.

The risk of abdominal injury to women during sport

Although trauma to pregnant women is a potential risk during sport, as there is no published information about the magnitude of this risk, it is presumed to be low. Whilst there is an emerging literature about the risk of adverse outcomes following severe and catastrophic trauma to pregnant women, this literature almost exclusively focuses on road trauma victims or the result of assault. This paper describes the risk of abdominal injuries to women participants across a range of sports in Australia. An extensive search of the available literature could not identify any studies that had discussed this issue specifically in pregnant women. Studies, which have reported injuries in athletes, have generally found abdominal/chest injuries to account for fewer than 2% of all injuries, even in contact sports. Most of these published studies do not differentiate between the chest and abdomen and provide no specfic details on the exact nature or mechanisms of the injuries. Given the limitations of the published studies, an examination of data from two Australian general injury databases (one describing hospital admissions, the other hospital emergency department presentations), three Australian sports-injury treatment databases (sports medicine clinic attendances and medical coverage services) and one cohort study was undertaken to describe sports-related abdominal injuries. These analyses confirm that the risk of abdominal injury during sport is very low. In conclusion, currently there is not an adequate evidence-base for quantifying the risk of abdominal injuries during sport in women, let alone pregnant women or for justifying a ban of sport on this basis. Recommendations for future epidemiological sports injury studies and the potential for linkages with perinatal morbidity and mortality databases are given.

Uterine artery embolization for symptomatic uterine myomas

OBJECTIVE

To evaluate the role of uterine artery embolization as treatment for symptomatic uterine myomas.

DESIGN

Medline literature review, cross-reference of published data, and review of selected meeting abstracts.

RESULT(S)

Results from clinical series have shown a consistent short-term reduction in uterine size, subjective improvement in uterine bleeding, and reduced pain following treatment. Posttreatment hospitalization and recovery tend to be shorter after uterine artery embolization compared with hysterectomy. Randomized controlled trials have not been conducted, and long-term efficacy has not been studied. A limited number of deliveries have been reported following uterine artery embolization for uterine myomas.

CONCLUSION(S)

Uterine artery embolization is a unique new treatment for symptomatic uterine myomas. Even without controlled studies, demand for this procedure has increased rapidly. Uterine artery embolization may be considered an alternative to hysterectomy, or perhaps myomectomy, in well-selected cases. At the present time, however, uterine artery embolization should not be routinely recommended for women who desire future fertility.