Effect of energy expenditure and physical activity on the outcomes of assisted reproduction treatment

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.

Association between domain-specific physical activity and mental health status after embryo transfer in IVF-ET-assisted pregnancy patients

Physical activity has been shown to impact mental health in in vitro fertilization-embryo transfer (IVF-ET) patients, but the relationship between domain-specific physical activity and mental health in this population remains unclear. In a cross-sectional observational study, 208 patients undergoing IVF-ET with long-term ovulation induction cycles were recruited from a reproductive center. The International Physical Activity Questionnaire and the symptom checklist 90 (SCL-90) were used to assess physical activity levels and mental health status, respectively. Analyses of variance and linear regression analyses were conducted to identify the relationship between physical activity and mental health. There were differences between different physical activity level in times of transfers, years of infertility, and times of abortions. Patients with high levels of physical activity had fewer symptoms than those with low levels of physical activity. Occupation, transport and household physical activity had significant negative correlations with the respective SCL-90 factor scores. Linear regression analysis revealed that occupation physical activity was associated with lower depression and anxiety, and transport physical activity and household physical activity were associated with lower obsessive-compulsive, interpersonal sensitivity, depression, anxiety, and psychoticism scores. The study indicates that increased engagement in physical activity, specifically activities related to occupation, transportation, and household, may be associated with improved mental health among IVF-ET patients.

Association of Outdoor Physical Activity and Sports with Life Satisfaction among Women of Reproductive Age According to a European Representative Sample-A Longitudinal Analysis

(1) Background: Low life satisfaction (LS) is associated with impaired mental and physical health. Outdoor physical activity (PA) has diverse somatic and psychological benefits. This study aimed to analyse the associations between sports settings and LS in women of reproductive age. (2) Methods: Special Eurobarometer on Sport and Physical Activity (2022, 2018, 2013) data on regularity and settings of sports/PA, LS and sociodemographic variables were analysed. The representative sample consisted of 18,489 women (34.60 ± 9.36 years). Pearson χ2 test and multivariate logistic regression analysis were conducted, using IBM SPSS version 28.0 according to the STROBE guidelines. The significance level was set at p < 0.05. (3) There was a significant difference in LS based on sports settings (χ2 = 409.696, p < 0.001). In the outdoor group, a 21.4% higher probability of being "very satisfied" compared to the non-outdoor, 30.0% higher compared to the inactive group, was found (R2N = 0.151). Dividing the sample by age, a significant effect remained in middle adulthood (35-44 years p = 0.002 and 45-49 years p = 0.033). (4) Conclusions: Our results underline the importance of the promotion of outdoor, green exercise and the development of special interventions to maintain or improve the psychological well-being of women in reproductive age.

The effect of physical activity on fertility: a mini-review

Although lifestyle factors such as diet, cigarette smoking, and alcohol consumption are increasingly recognized as important contributors to the risk of subfertility, the role of exercise in fertility remains less clear. As such, it is challenging for healthcare providers to deliver clear, evidence-based recommendations to patients regarding the optimal frequency and intensity with which they should exercise to maximize their chances of conception. Therefore, this review provides a critical overview of the available research for various patient populations.

High physical activity and ovarian reserve: a prospective study of normo-ovulatory professional athletes

Background

This study investigated whether high physical activity affects ovarian reserve in normo-ovulatory, reproductive-age women.

Methods

This prospective, observational study compared 31 professional female athletes, with 31 women who did not engage in physical activity. It was conducted 2017–2020 in a tertiary medical center. Normo-ovulatory, professional athletes, ages 20–35 years were recruited from The Wingate Institute—the Israeli National Institute for Sport Excellence. They had high International Physical Activity Questionnaire (IPAQ) scores. Non-physically active women, matched by age and body mass index, were recruited from hospital staff. Women were evaluated for ovarian reserve markers on day 2–5 of the menstrual cycle, including follicular stimulating hormone, antral follicle count, anti-Mullerian hormone and Inhibin B.

Results

The average age of the high physical activity group was 29.9 ± 4.2 years and the nonactive group 31.6 ± 4.2 years (p = 0.062). Body mass index of both groups were similar (22.5 ± 5.0 vs. 21.4 ± 2.5, respectively; p = 0.1). No differences were observed with respect to follicle stimulating hormone (p = 0.12) and anti-Mullerian hormone (p = 0.16). A trend towards higher total antral follicle count in the high physical activity group vs. the non-active group (34.5 ± 12.9 vs. 28.1 ± 15.2, p = 0.08) and lower Inhibin B (68.1 ± 36.8 vs. 89.4 ± 46.1, p = 0.05). Menarche age correlated with anti-Mullerian hormone (r = 0.387, p = 0.003), as did total antral follicle count (r = 0.368, p = 0.004). IPAQ scores and basal follicle stimulating hormone levels were negatively correlated (r = − 0.292, p = 0.005).

Conclusions

Athletic, normo-ovulatory women have ovarian reserves that are at least as good as those of the general population. As this is the first study examining this issue, it could cautiously reassure women engaged in high physical activity regarding ovarian reserve.

The role of maternal physical activity on in vitro fertilization outcomes: a systematic review and meta-analysis

PURPOSE

This systematic review is designed to summarize the evidence concerning the impact of maternal physical activity on the reproductive outcomes following assisted reproduction techniques (ART), namely in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI).

METHODS

We searched for eligible studies on PubMed, EMBASE databases and the Cochrane Library from their inception until September 2021. Our primary outcomes were live birth rate and miscarriage, while secondary ones included clinical pregnancy and implantation rates. The quality of the evidence was evaluated using a study-specific adaptation of the Robins I tool.

RESULTS

Quantitative data from 10 cohort studies (CS) and 2 randomized control trials (RCT), involving 3431 women undergoing ART treatments, were included in the analyses. The pooled results exhibited uncertainty regarding the effect of physical activity on live birth rate per woman (OR 1.15, 95% CI 0.92-1.43, p = 0.23, I² = 61%, 9 studies) and miscarriage rates (OR 0.79, 95% CI 0.44-1.43, p = 0.43, I² = 44%, 6 studies). However, physical activity was associated with significantly improved clinical pregnancy rate after ART (OR 1.39, 95% CI 1.08-1.79, p = 0.0009, I² = 68%, 10 studies), whereas implantation rate after ART almost reached statistical significance (OR = 1.95, 95% CI 0.99-3.82, p = 0.05, I² = 77%).

CONCLUSION

The current evidence is still insufficient to firmly conclude on the effect of maternal physical activity on live birth, miscarriage and implantation rates. Although clinical pregnancy rates favored physical activity in this group of patients, these results must be undertaken with caution due to the low quality and the high heterogeneity of the studies included.

Unraveling the Balance between Genes, Microbes, Lifestyle and the Environment to Improve Healthy Reproduction

Humans’ health is the result of a complex and balanced interplay between genetic factors, environmental stimuli, lifestyle habits, and the microbiota composition. The knowledge about their single contributions, as well as the complex network linking each to the others, is pivotal to understand the mechanisms underlying the onset of many diseases and can provide key information for their prevention, diagnosis and therapy. This applies also to reproduction. Reproduction, involving almost 10% of our genetic code, is one of the most critical human’s functions and is a key element to assess the well-being of a population. The last decades revealed a progressive decline of reproductive outcomes worldwide. As a consequence, there is a growing interest in unveiling the role of the different factors involved in human reproduction and great efforts have been carried out to improve its outcomes. As for many other diseases, it is now clear that the interplay between the underlying genetics, our commensal microbiome, the lifestyle habits and the environment we live in can either exacerbate the outcome or mitigate the adverse effects. Here, we aim to analyze how each of these factors contribute to reproduction highlighting their individual contribution and providing supporting evidence of how to modify their impact and overall contribution to a healthy reproductive status.

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

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

Pretreatment maternal lifestyle and outcomes of assisted reproduction: an Italian cohort study

OBJECTIVE

We investigated whether lifestyle affects assisted reproduction technology (ART) outcomes.

DESIGN

Cohort study.

SETTING

Italian fertility unit.

PARTICIPANTS

From September 2014 to December 2016, women from couples presenting for evaluation and eligible for ART were invited to participate. Information on alcohol intake, current smoking and leisure physical activity (PA) during the year before the interview was collected, using a structured questionnaire. We considered the ART outcomes of the cycle immediately following the interview.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome measure was cumulative pregnancy rate per retrieval. Secondary measures were number of retrieved oocytes, embryo transfer and live birth.

RESULTS

In 492 women undergoing an ART cycle, 427 (86.8%) underwent embryo transfer, 157 (31.9%) had at least one clinical pregnancy and 121 (24.6%) had live birth. The cumulative pregnancy rate per retrieval was 33.3% (95% CI 28.5% to 38.7%). In women in the third tertile of alcohol intake, adjusted relative risk was 0.97 (95% CI 0.87 to 1.08), 0.90 (95% CI 0.62 to 1.30) and 0.89 (95% CI 0.57 to 1.37) for embryo transfer, clinical pregnancy and live birth, respectively. The corresponding figures in women currently smoking more than 5 cigarettes/day were 1.00 (95% CI 0.88 to 1.16), 0.94 (95% CI 0.60 to 1.48) and 1.14 (95% CI 0.68 to 1.90), and in women with PA ≥5 hours/week were 0.93 (95% CI 0.79 to 1.08), 0.44 (95% CI 0.22 to 0.90) and 0.48 (95% CI 0.22 to 1.05), respectively.

CONCLUSION

There were no significant differences in in vitro fertilisation outcomes among women who used alcohol or tobacco in the year prior to treatment. Conservatively, all women should be advised to limit substance abuse. Moreover, our study suggested that maintaining a moderate, but not high, level of PA could be beneficial.

Maternal physical activity and sedentary behaviour before and during in vitro fertilization treatment: a longitudinal study exploring the associations with controlled ovarian stimulation and pregnancy outcomes

PURPOSE

To evaluate the association of objectively measured physical activity (PA) and sedentary behaviour before and during in vitro fertilization (IVF) with controlled ovarian stimulation (COS) and pregnancy outcomes.

METHODS

This longitudinal study involved 107 infertile women undergoing IVF treatment. PA and sedentary behaviour were measured for 14 consecutive days using accelerometry as follows: (1) before IVF treatment, (2) during IVF at the implantation time, immediately after embryo transfer, and (3) after positive pregnancy test. Total screen time was assessed by questionnaires. COS results were measured as the number of oocytes and embryos obtained, and the study outcomes included positive hCG, clinical pregnancy, and live birth.

RESULTS

Compared with baseline activity levels, women significantly reduced their PA and increased sedentary behaviour during IVF (p ≤ 0.001). Higher average PA, light PA, and ratio between breaks in every ≥ 30-min blocks of sedentary time showed positive associations, while sedentary time, number, and time accumulated in blocks of ≥ 30 min of sedentary time associated negatively with oocyte and embryo counts (all p < 0.05). Women with high total screen time during non-work days (≥ 7 h) obtained 4.7 oocytes (p = 0.005) and 2.8 embryos (p = 0.008) less in COS. PA and sedentary behaviour before and during IVF did not affect the positive hCG, clinical pregnancy, and live birth outcomes.

CONCLUSION

Our study results suggest that higher time spent in PA and lower time spent in sedentary behaviour before entering assisted reproduction is associated with better COS outcomes, while activity levels before and during IVF do not affect the implantation, pregnancy, and live birth outcomes.

Determining the association between physical activity prior to conception and pregnancy rate: A systematic review and meta-analysis of prospective cohort studies

We investigated the association between physical activity (PA) before pregnancy and pregnancy rate according to intensity and amount of exercise. Eleven prospective cohort studies were included in this meta-analysis. Any amount of moderate-intensity PA was associated with a statistically higher rate of pregnancy compared to that in patients with no PA (p < .05). Any amount of vigorous PA was associated with decreased pregnancy rate; regular PA was associated with decreased infertility (p > .05). In contrast, vigorous PA was associated with increased infertility (p > .05). Therefore, women who are preparing for pregnancy are recommended to perform regular, moderate-intensity PA.

Sedentary behavior, physical inactivity and body composition in relation to idiopathic infertility among men and women

BACKGROUND

Physical activity (PA) and sedentary behavior have inconsistent effects on fertility. High body mass index is associated with infertility but to our knowledge, very few studies have explored body composition in association to fertility.

OBJECTIVE

To assess the association between physical inactivity, sedentary behavior, body composition and idiopathic infertility in French men and women.

DESIGN

We conducted a case-control multicentric observational study. 159 infertile (79 men and 80 women) and 143 fertile (72 men and 71 women) were recorded in four fertility centers.

MAIN OUTCOME MEASURES

Participants completed self-administered questionnaires on sociodemographic and lifestyle characteristics, dietary intake, physical activity and sedentary behavior. Anthropometrics were measured, and bioelectrical impedance analysis was used to estimate body composition. Multivariable logistic regression was used to analyze the association of fertility with PA level and sedentary behavior.

RESULTS

In men, being physically inactive (Odd ratio [OR] 2.20; 95% confidence interval [CI], 1.06, 4.58) and having fat mass greater than the reference values for their age (OR 2.83; 95%CI, 1.31, 6.10) were positively associated with infertility. Sedentary behavior and fat-free mass were not related to infertility in men. In women, sedentary behavior (OR 3.61; 95%CI, 1.58, 8.24), high body fat (OR 3.16; 95%CI, 1.36, 7.37) and low fat-free mass (OR 2.65; 95%CI, 1.10, 6.37) were associated with infertility. PA level was not associated with fertility in women.

CONCLUSIONS

This study suggests that sedentary behavior and physical inactivity would represent two independent risk factors associated with infertility. The various elements that make up physical activity (frequency, intensity, time, and type of exercise) and the interrupting time spent sitting should be considered. Body composition variation should be explored further in relation to the biological pathways involved in idiopathic infertility. Moreover, the improvement of lifestyle factors should be considered in infertility treatment.

A prospective study of physical activity and fecundability in women with a history of pregnancy loss

STUDY QUESTION

Is physical activity (PA) associated with fecundability in women with a history of prior pregnancy loss?

SUMMARY ANSWER

Higher fecundability was related to walking among overweight/obese women and to vigorous PA in women overall.

WHAT IS KNOWN ALREADY

PA may influence fecundability through altered endocrine function. Studies evaluating this association have primarily utilized Internet-based recruitment and self-report for pregnancy assessment and have yielded conflicting results.

STUDY DESIGN, SIZE, DURATION

This is a secondary analysis of the Effects of Aspirin in Gestation and Reproduction (EAGeR) trial (2007-2011), a multisite, randomized controlled trial of preconception-initiated low-dose aspirin.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Healthy women (n = 1214), aged 18-40 and with 1-2 prior pregnancy losses, were recruited from four US medical centers. Participants were followed for up to six menstrual cycles while attempting pregnancy and through pregnancy for those who became pregnant. Time to hCG detected pregnancy was assessed using discrete-time Cox proportional hazard models to estimate fecundability odds ratios (FOR) adjusted for covariates, accounting for left truncation and right censoring.

MAIN RESULTS AND THE ROLE OF CHANCE

The association of walking with fecundability varied significantly by BMI (P-interaction = 0.01). Among overweight/obese women, walking ≥10 min at a time was related to improved fecundability (FOR = 1.82, 95% CI: 1.19, 2.77). In adjusted models, women reporting >4 h/wk of vigorous activity had significantly higher fecundability (FOR = 1.69, 95% CI: 1.24, 2.31) compared to no vigorous activity. Associations of vigorous activity with fecundability were not significantly different by BMI (P-interaction = 0.9). Moderate activity, sitting, and International Physical Activity Questionnaire (IPAQ) categories were not associated with fecundability overall or in BMI-stratified analyses.

LIMITATIONS, REASONS FOR CAUTION

Some misclassification of PA levels as determined by the short form of the IPAQ is likely to have occurred, and may have led to non-differential misclassification of exposure in our study. Information on diet and change in BMI was not collected and may have contributed to some residual confounding in our results. The generalizability of our results may be limited as our population consisted of women with a history of one or two pregnancy losses.

WIDER IMPLICATIONS OF THE FINDINGS

These findings provide positive evidence for the benefits of PA in women attempting pregnancy, especially for walking among those with higher BMI. Further study is necessary to clarify possible mechanisms through which walking and vigorous activity might affect time-to-pregnancy.

STUDY FUNDING/COMPETING INTEREST(S)

This work was funded by the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development. The authors report no conflicts of interest in this work.

TRIAL REGISTRATION NUMBER

#NCT00467363.

Maternal physical activity before IVF/ICSI cycles improves clinical pregnancy rate and live birth rate: a systematic review and meta-analysis

OBJECTIVE

This meta-analysis was aimed to evaluate the association between maternal physical activity before IVF/ICSI cycles and reproductive outcomes.

METHODS

We searched databases of PubMed, EMBASE and Web of Science electronic databases, and ongoing trials up to November 2017 to identify studies that focused on the relationship between maternal physical activity before IVF/ICSI cycles and reproductive outcomes, including implantation rate, clinical pregnancy rate, miscarriage rate and live birth rate. Odds ratio (OR) with 95% confidence intervals, were calculated to assess the results of each outcome.

RESULTS

Eight published studies encompassing 3683 infertile couples undergoing IVF/ICSI treatment were included into the analysis. There was an increasing, but not statistically significant, trend in implantation rate for physically active women when compared with physically inactive women (OR = 1.95, 95% CI 0.99-3.83, I2 = 77%). No significant difference was found in miscarriage rate between physically active women and physically inactive women (OR = 0.76, 95% CI 0.41-1.44, I2 = 49%). However, rates of clinical pregnancy and live births in physically active women were significantly higher than those in physically inactive women (OR = 1.96, 95% CI 1.40, 2.73, I2 = 42% and OR = 1.95, 95% CI 1.06-3.59, I2 = 82%, respectively). Subgroup analysis helped to confirm these results.

CONCLUSIONS

Female physical activity before IVF/ICSI cycles was associated with increased rates of clinical pregnancy and live births, whereas only a small but not statistically significant increase was found in implantation rate, and no effect was shown on miscarriage rate.

The Effect of Moderate Physical Activity on Ovarian Reserve Markers in Reproductive Age Women Below and Above 30 Years

Background:

There is significant evidence among the general population regarding the impact of physical activity in improving the quality of life; however, evidence regarding the effect of physical activity in improving fertility and the quality of life in infertile women is inadequate. Existing medical literature shows that moderately regular physical activity positively influences ovarian reserve and assisted reproductive technology (ART) outcomes in overweight and obese women. It is not known whether moderate physical activity influences ovarian reserve in normal weight reproductive age women, and whether age has any influence on the physical activity related changes in ovarian reserve.

Objectives:

The objectives of the study were (1) to study the impact of moderate physical activity on ovarian reserve markers in normal weight reproductive age women and (2) to understand whether age influences the effect of physical activity on ovarian reserve markers in reproductive age women.

Methods:

This observational, cross-sectional study included 162 married women in the age group of 19–42 years, who were evaluated for ovarian reserve markers antimullerian hormone (AMH), follicular stimulating hormone (FSH), and antral follicle count (AFC) on the days 3–6 of the menstrual cycle. The study participants were divided into two age groups (above and below 30 years) and physically active and inactive groups. Ovarian reserve markers were compared among both the age groups and the physically active and inactive participants by analysis of variance.

Results:

When the study participants in both the age groups were compared for the effect of moderate exercise on ovarian reserve profile, better ovarian reserve profile was observed in the physically active participants in both the age groups. Significant differences were not seen with respect to FSH level (P = 0.371) and AFC (P = 0.483) in both the age groups, but significant difference was observed with respect to AMH level in the below 30 years age group compared to the above 30 years age group (P ≤ 0.001).

Conclusion:

This study demonstrated that moderate physical activity is associated with improved age-specific levels of ovarian reserve markers.

Maternal physical and sedentary activities in relation to reproductive outcomes following IVF

Physical activity could benefit reproductive function through its ability to regulate energy balance and improve insulin sensitivity, but its association with IVF outcomes remains unclear. The aim of this study was to evaluate whether pre-treatment physical and sedentary activity is associated with outcomes of IVF. The Environment and Reproductive Health Study is an ongoing prospective cohort study that enrols subfertile couples at Massachusetts General Hospital Fertility Center. Time spent in physical and sedentary activities in the year before IVF treatment is self-reported using a validated questionnaire. This analysis included 273 women who underwent 427 IVF cycles. Women engaged in a median of 2.8 h per week of moderate-to-vigorous activities. Time spent in moderate-to-vigorous physical activities and total metabolic equivalent task hours before IVF were not associated with probability of implantation, clinical pregnancy or live birth. Of the specific physical activities, only greater time spent in aerobics, rowing, and on the ski or stair machine was associated with higher probability of live birth. Time spent in total and specific sedentary activities were not associated with clinical outcomes of IVF. Physical activity is unlikely to have a deleterious effect on IVF success and certain forms of vigorous activity may be beneficial.

The Role of Physical Activity in Preconception, Pregnancy and Postpartum Health

The rise in obesity and associated morbidity is currently one of our greatest public health challenges. Women represent a high risk group for weight gain with associated metabolic, cardiovascular, reproductive and psychological health impacts. Regular physical activity is fundamental for health and well-being with protective benefits across the spectrum of women's health. Preconception, pregnancy and the early postpartum period represent opportune windows to engage women in regular physical activity to optimize health and prevent weight gain with added potential to transfer behavior change more broadly to children and families. This review summarizes the current evidence for the role of physical activity for women in relation to preconception (infertility, assisted reproductive therapy, polycystic ovary syndrome, weight gain prevention and psychological well-being) pregnancy (prevention of excess gestational weight gain, gestational diabetes and preeclampsia as well as labor and neonatal outcomes) and postpartum (lactation and breastfeeding, postpartum weight retention and depression) health. Beneficial outcomes validate the importance of regular physical activity, yet key methodological gaps highlight the need for large, high-quality studies to clarify the optimal type, frequency, duration and intensity of physical activity required for beneficial health outcomes during preconception, pregnancy and postpartum.

Body mass index, physical activity and fecundability in a North American preconception cohort study

OBJECTIVE

To evaluate the association between adiposity, physical activity (PA), and fecundability.

DESIGN

Prospective cohort study.

SETTING

Not applicable.

PATIENT(S)

A total of 2,062 female pregnancy planners from the United States and Canada who were enrolled during the preconception period.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Self-reported pregnancy. Fecundability ratios (FRs) and 95% confidence intervals (CIs) were estimated using proportional probabilities models that adjusted for potential confounders.

RESULT(S)

Relative to body mass index (BMI) 18.5-24 kg/m(2), FRs for BMI <18.5, 25-29, 30-34, 35-39, 40-44, and ≥45 kg/m(2) were 1.05 (95% CI 0.76-1.46), 1.01 (95% CI 0.89-1.15), 0.98 (95% CI 0.82-1.18), 0.78 (95% CI 0.60-1.02), 0.61 (95% CI 0.42-0.88), and 0.42 (95% CI 0.23-0.76), respectively. Reduced fecundability was observed among women with the largest waist-to-hip ratios (≥0.85 vs. <0.75; FR = 0.87, 95% CI 0.74-1.01) and waist circumferences (≥36 vs. <26 inches [≥90 vs. <66 cm]; FR = 0.80, 95% CI 0.59-1.01). Tendency to gain weight in the chest/shoulders (FR = 0.63, 95% CI 0.36-1.08) and waist/stomach (FR = 0.90, 95% CI 0.79-1.02), relative to hips/thighs, was associated with lower fecundability. Moderate PA was associated with increased fecundability (≥5 vs. <1 h/wk; FR = 1.26, 95% CI 0.96-1.65), but there was no dose-response relation. Among overweight/obese women (BMI ≥25 kg/m(2)), fecundability was 27% higher for vigorous PA of ≥5 versus <1 h/wk (95% CI 1.02-1.57).

CONCLUSION(S)

Various measures of overall and central adiposity were associated with decreased fertility among pregnancy planners. Vigorous PA was associated with improved fertility among overweight and obese women only; moderate PA was associated with improved fertility among all women.

Association of physical activity in the past year and immediately after in vitro fertilization on pregnancy

OBJECTIVE

To estimate the association of physical activity on in vitro fertilization (IVF).

DESIGN

Prospective cohort study.

SETTING

Academic infertility clinic.

PATIENT(S)

Women (n = 121) undergoing nondonor IVF embryo transfer (fresh or frozen).

INTERVENTION(S)

The women completed a questionnaire on past year physical activity and wore an accelerometer from embryo transfer to serum pregnancy testing.

MAIN OUTCOME MEASURE(S)

Implantation, intrauterine gestation, and live birth.

RESULT(S)

Based on self-reported past year physical activity, the adjusted odds of intrauterine gestation was higher among those that had higher continuous active living (odds ratio [OR] 1.96, 95% confidence interval [CI] 1.09-3.50), sports/exercise (OR 1.48, CI 1.02-2.15), and total activity (OR 1.52, 95%CI 1.15-2.01) indices. After embryo transfer, women did almost no vigorous activity (median 0 min/d) as measured by the accelerometer. More of their time was spent in light activity (median 3.0 h/d) and sedentary behaviors (median 9.3 h/d). Accelerometer-measured physical activity and sedentary behavior after embryo transfer were not associated with any IVF outcome.

CONCLUSION(S)

An active lifestyle in the preceding year favorably impacted the IVF outcome. After embryo transfer, women engaged in mostly light physical activity and sedentary behaviors; therefore, the impact of vigorous physical activity on implantation could not be determined.

The relationship between physical aspects of quality of life and extreme levels of regular physical activity in adults

This study aimed to check for any significant differences in perceived quality of life, specifically aspects of a physical nature, among volunteers who are more physically active and those less physically active in a university community. The sample consisted of 1,966 volunteers in a university community in Brazil. To assess physical activity levels, volunteers responded to the International Physical Activity Questionnaire (IPAQ), and to analyse the perception of quality of life they responded to WHOQOL-bref, which is classified into three groups according to level of physical activity, taking into account the metabolic equivalent index (MET) over a full week. For comparison, consideration was given to the first and third tertiles, respectively, namely groups of more and less active students. The results indicated that individuals who engaged in more physical activity had a more positive perception of quality of life compared to those who were less active in physical aspects related to the ability to work, energy for day-to-day activities and locomotion.

A prospective cohort study of physical activity and time to pregnancy

OBJECTIVE

To investigate the association between leisure-time physical activity (PA) and fecundability.

DESIGN

Prospective cohort study.

SETTING

Internet-based observational study of Danish women who were planning a pregnancy (2007-2009).

PATIENT(S)

A total of 3,628 women aged 18-40 years at baseline.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Time to pregnancy (TTP). Fecundability ratios (FRs) and 95% confidence intervals (CIs) were derived from discrete-time Cox models, with adjustment for potential confounders, such as body mass index (BMI).

RESULT(S)

We observed an inverse monotonic association between vigorous PA and fecundability (≥ 5 h/wk vs. none: FR 0.68, 95% CI 0.54-0.85) and a weak positive association between moderate PA and fecundability (≥ 5 vs. <1 h/wk: FR 1.18, 95% CI 0.98-1.43) after mutual adjustment for both PA types. Inverse associations between high vigorous PA and fecundability were observed within subgroups of age, parity status, and cycle regularity, but not among overweight or obese women (BMI ≥ 25 kg/m(2)).

CONCLUSION(S)

There was evidence for a dose-response relationship between increasing vigorous PA and delayed TTP in all subgroups of women with the exception of overweight and obese women. Moderate PA was associated with a small increase in fecundability regardless of BMI. These findings indicate that PA of any type might improve fertility among overweight and obese women, a subgroup at higher risk of infertility. Lean women who substitute vigorous PA with moderate PA may also improve their fertility.