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Journal of Science and Medicine in Sport Dec 2020To systematically review the current body of research that has investigated changes in strength-related variables during different phases of the menstrual cycle in... (Meta-Analysis)
Meta-Analysis
OBJECTIVES
To systematically review the current body of research that has investigated changes in strength-related variables during different phases of the menstrual cycle in eumenorrheic women.
DESIGN
Systematic review and meta-analysis.
METHODS
A literature search was conducted in Pubmed, SPORTDiscus and Web of Science using search terms related to the menstrual cycle and strength-related measures. Two reviewers reached consensus that 21 studies met the criteria for inclusion. Methodological rigour was assessed using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Random effects meta-analyses were used to compare the early-follicular, ovulatory and mid-luteal phases for maximal voluntary contraction, isokinetic peak torque, and explosive strength.
RESULTS
The assessment of study quality showed that a high level of bias exists in specific areas of study design. Non-significant and small or trivial effect sizes (p≥0.26, Hedges g≤0.35) were identified for all strength-related variables in each comparison between phases. 95% confidence intervals for each comparison suggested the uncertainty associated with each estimate extends to a small effect on strength performance with unclear direction (-0.42≤g≤0.48). The heterogeneity for each comparison was also small (p≥0.83, I=0%).
CONCLUSIONS
Strength-related measures appear to be minimally altered (g≤0.35) by the fluctuations in ovarian sex hormones that occur during the menstrual cycle. This finding should be interpreted with caution due to the methodological shortcomings identified by the quality assessment.
Topics: Athletic Performance; Estrogens; Female; Humans; Menstrual Cycle; Muscle Strength; Progesterone; Research Design
PubMed: 32456980
DOI: 10.1016/j.jsams.2020.04.022 -
Sports Medicine (Auckland, N.Z.) Jan 2020Resistance training is well known to increase strength and lean body mass, and plays a key role in many female athletic and recreational training programs. Most females...
BACKGROUND
Resistance training is well known to increase strength and lean body mass, and plays a key role in many female athletic and recreational training programs. Most females train throughout their reproductive years when they are exposed to continuously changing female steroid hormone profiles due to the menstrual cycle or contraceptive use. Therefore, it is important to focus on how female hormones may affect resistance training responses.
OBJECTIVE
The aim of this systematic review is to identify and critically appraise current studies on the effect of the menstrual cycle and oral contraceptives on responses to resistance training.
METHODS
The electronic databases Embase, PubMed, SPORTDiscus and Web of Science were searched using a comprehensive list of relevant terms. Studies that investigated the effect of the menstrual cycle phase or oral contraceptive cycle on resistance training responses were included. Studies were also included if they compared resistance training responses between the natural menstrual cycle and oral contraceptive use, or if resistance training was adapted to the menstrual cycle phase or oral contraceptive phase. Studies were critically appraised with the McMasters Universities Critical Review Form for Quantitative Studies and relevant data were extracted.
RESULTS
Of 2007 articles found, 17 studies met the criteria and were included in this systematic review. The 17 included studies had a total of 418 participants with an age range of 18-38 years. One of the 17 studies found no significant differences in acute responses to a resistance training session over the natural menstrual cycle, while four studies did find changes. When assessing the differences in acute responses between the oral contraceptive and menstrual cycle groups, two studies reported oral contraceptives to have a positive influence, whilst four studies reported that oral contraceptive users had a delayed recovery, higher levels of markers of muscle damage, or both. For the responses to a resistance training program, three studies reported follicular phase-based training to be superior to luteal phase-based training or regular training, while one study reported no differences. In addition, one study reported no differences in strength development between oral contraceptive and menstrual cycle groups. One further study reported a greater increase in type I muscle fibre area and a trend toward a greater increase in muscle mass within low-androgenic oral contraceptive users compared with participants not taking hormonal contraceptives. Finally, one study investigated androgenicity of oral contraceptives and showed greater strength developments with high androgenic compared with anti-androgenic oral contraceptive use.
CONCLUSIONS
The reviewed articles reported conflicting findings, and were often limited by small participant numbers and methodological issues, but do appear to suggest female hormones may affect resistance training responses. The findings of this review highlight the need for further experimental studies on the effects of the menstrual cycle and oral contraceptives on acute and chronic responses to resistance training.
Topics: Body Composition; Contraceptives, Oral; Female; Humans; Menstrual Cycle; Muscle Strength; Resistance Training
PubMed: 31677121
DOI: 10.1007/s40279-019-01219-1 -
BMJ Open Sport & Exercise Medicine 2021Exercising women report three to six times more ACL tears than men, which happen, in the majority of cases, with a non-contact mechanism. This sex disparity has, in...
Effect of menstrual cycle phase, menstrual irregularities and hormonal contraceptive use on anterior knee laxity and non-contact anterior cruciate ligament injury occurrence in women: a protocol for a systematic review and meta-analysis.
Exercising women report three to six times more ACL tears than men, which happen, in the majority of cases, with a non-contact mechanism. This sex disparity has, in part, been attributed to the differences in reproductive hormone profiles between men and women. Many studies have shown that anterior knee (AK) laxity and the rate of non-contact ACL injuries vary across the menstrual cycle, but these data are inconsistent. Similarly, several studies have investigated the potential protective effect of hormonal contraceptives on non-contact ACL injuries, but their conclusions are also variable. The purpose of this systematic review and meta-analysis is to, identify, evaluate and summarise the effects of endogenous and exogenous ovarian hormones on AK laxity (primary outcome) and the occurrence of non-contact ACL injuries (secondary outcome) in women. We will perform a systematic search for all observational studies conducted on this topic. Studies will be retrieved by searching electronic databases, clinical trial registers, author's personal files and cross-referencing selected studies. Risk of bias will be assessed using the Newcastle Ottawa Quality Assessment Scale for Cohort and Case-Control Studies. Certainty in the cumulative evidence will be assessed using the Grading of Recommendations Assessment, Development and Evaluation approach. The meta-analyses will use a Bayesian approach to address specific research questions in a more intuitive and probabilistic manner. This review is registered on the international database of prospectively registered systematic reviews (PROSPERO; CRD42021252365).
PubMed: 34745647
DOI: 10.1136/bmjsem-2021-001170 -
PloS One 2023Eumenorrheic women experience cyclic variations in sex hormones attributed to the menstrual cycle (MC) which can impact anterior cruciate ligament (ACL) properties, knee...
Effects of the menstrual cycle phase on anterior cruciate ligament neuromuscular and biomechanical injury risk surrogates in eumenorrheic and naturally menstruating women: A systematic review.
BACKGROUND
Eumenorrheic women experience cyclic variations in sex hormones attributed to the menstrual cycle (MC) which can impact anterior cruciate ligament (ACL) properties, knee laxity, and neuromuscular function. This systematic review aimed to examine the effects of the MC on ACL neuromuscular and biomechanical injury risk surrogates during dynamic tasks, to establish whether a particular MC phase predisposes women to greater ACL injury risk.
METHODS
PubMed, Medline, SPORTDiscus, and Web of Science were searched (May-July 2021) for studies that investigated the effects of the MC on ACL neuromuscular and biomechanical injury risk surrogates. Inclusion criteria were: 1) injury-free women (18-40 years); 2) verified MC phases via biochemical analysis and/or ovulation kits; 3) examined neuromuscular and/or biomechanical injury risk surrogates during dynamic tasks; 4) compared ≥1 outcome measure across ≥2 defined MC phases.
RESULTS
Seven of 418 articles were included. Four studies reported no significant differences in ACL injury risk surrogates between MC phases. Two studies showed evidence the mid-luteal phase may predispose women to greater risk of non-contact ACL injury. Three studies reported knee laxity fluctuated across the MC; two of which demonstrated MC attributed changes in knee laxity were associated with changes in knee joint loading (KJL). Study quality (Modified Downs and Black Checklist score: 7-9) and quality of evidence were low to very low (Grading of Recommendations Assessment Development and Evaluation: very low).
CONCLUSION
It is inconclusive whether a particular MC phase predisposes women to greater non-contact ACL injury risk based on neuromuscular and biomechanical surrogates. Practitioners should be cautious manipulating their physical preparation, injury mitigation, and screening practises based on current evidence. Although variable (i.e., magnitude and direction), MC attributed changes in knee laxity were associated with changes in potentially hazardous KJLs. Monitoring knee laxity could therefore be a viable strategy to infer possible ACL injury risk.
Topics: Humans; Female; Anterior Cruciate Ligament; Anterior Cruciate Ligament Injuries; Menstruation; Joint Instability; Knee Joint; Menstrual Cycle; Biomechanical Phenomena
PubMed: 36701354
DOI: 10.1371/journal.pone.0280800 -
Revista Colombiana de Obstetricia Y... Jun 2020To conduct a systematic review of the literature and assess the acceptability and safety of the menstrual cup as a feminine hygiene product.
OBJECTIVES
To conduct a systematic review of the literature and assess the acceptability and safety of the menstrual cup as a feminine hygiene product.
MATERIALS AND METHODS
A search was conducted in the PubMed, Cochrane Library, Scopus, PopLine and Google Scholar databases for publications be- tween 1966 and July 2019. The terms ("Menstrual" AND "Cup") OR ("Copa" AND "Menstrual") were used. Quantitative, qualitative and mixed studies were included, as well as case series and case reports published in English and Spanish assessing the menstrual cup in women in childbearing age. The studies were selected and the data extracted by two reviewers working independently. Acceptability and safety were assessed as the primary result. The summary of the information is presented in narrative form.
RESULTS
Overall, 737 titles were found for initial review and, in the end, 38 studies were included in this work. The acceptability of the menstrual cup ranges between 35 % and 90 %. Between 10 to 45 % of women found it difficult to use. It was described as more comfortable when compared to tampons and pads. Continued use of the cup ranges between 48 and 94 %. In terms of safety, there was one case of toxic shock syndrome, one case of mechanical entrapment, and another case of allergy; and a higher risk of expulsion was found among intrauterine device users.
CONCLUSION
The menstrual cup appears to be a comfortable, safe and efficient option for menstrual hygiene. Further randomized controlled studies and long-term prospective cohort studies are needed in order to determine the risk of complications due to excess bacterial colonization or retrograde menstruation.
Topics: Adolescent; Adult; Cross-Sectional Studies; Equipment Contamination; Equipment Design; Female; Humans; Menstrual Hygiene Products; Middle Aged; Patient Acceptance of Health Care; Prospective Studies; Randomized Controlled Trials as Topic; Shock, Septic; Young Adult
PubMed: 32770872
DOI: 10.18597/rcog.3425 -
Fertility and Sterility Oct 2022To synthesize the published literature to better understand the association between cesarean scar defects (CSDs) and abnormal uterine bleeding (AUB). In particular, we... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To synthesize the published literature to better understand the association between cesarean scar defects (CSDs) and abnormal uterine bleeding (AUB). In particular, we aimed to evaluate the risk and pattern(s) of CSD-associated AUB in addition to exploring the relationship between defect morphology with bleeding symptoms.
DESIGN
Systematic review and meta-analysis.
SETTING
Not applicable.
PATIENTS
Patients with CSD and reports of uterine bleeding as an outcome were identified in 60 studies from database searches.
INTERVENTIONS
Studies that investigated CSD (as defined by investigators) and reported uterine bleeding, menstrual bleeding, or AUB as an outcome were included.
MAIN OUTCOME MEASURES
The prevalence and risk of AUB (intermenstrual, postmenstrual, and unscheduled bleeding) in patients with confirmed CSD.
RESULTS
Nine studies reported on the prevalence of AUB in patients with a confirmed CSD. Patients with CSD were more likely to experience AUB, compared with those without CSD (relative risk, 3.47; 95% confidence interval [CI], 2.02-5.97; 6 studies, 1,385 patients; I = 67%). In a population of patients with at least 1 cesarean delivery, the prevalence of AUB in those with CSD was 25.5% (95% CI, 14.7-40.5; 6 studies, 667 patients, I = 93%). However, symptom prevalence was much higher in patients presenting for imaging for a gynecologic indication where the prevalence of AUB in the presence of a CSD was 76.4% (95% CI, 67.8-83.3; 5 studies, 505 patients; I = 71%). The mean menstrual duration in symptomatic patients with CSD was 13.4 days (95% CI, 12.6-14.2; 19 studies, 2,095 patients; I = 96%), and the mean duration of early-cycle intermenstrual bleeding was 6.8 days (95% CI, 5.7-7.8 days; 9 studies, 759 patients; I = 93%). The most common descriptor of CSD-associated AUB was "brown discharge". Patients with larger CSD experienced more bleeding symptoms.
CONCLUSION
There is a strong and consistent association between patients with CSD and AUB. These patients experience a unique bleeding pattern, namely prolonged menstruation and early-cycle intermenstrual bleeding. These data should provide impetus for including CSD as a distinct entity in AUB classification systems. High heterogeneity in our results calls for standardization of nomenclature and outcome reporting for this condition.
Topics: Cesarean Section; Cicatrix; Female; Humans; Metrorrhagia; Pregnancy; Uterine Diseases; Uterine Hemorrhage
PubMed: 35985862
DOI: 10.1016/j.fertnstert.2022.06.031 -
Sports (Basel, Switzerland) Jan 2024Maximal strength is a significant factor in achieving peak performance and injury prevention in athletes. In individualization strategies for the efficient development... (Review)
Review
Maximal strength is a significant factor in achieving peak performance and injury prevention in athletes. In individualization strategies for the efficient development of athletes, it is necessary to consider the respective components separately. The purpose of this study was to systematically examine the effects of the different cycle phases on isometric, isokinetic, and dynamic maximum strength. A systematic literature review was conducted; databases were searched from January 1960 to September 2023. The included studies focused on the expression of maximal strength in the earlier follicular phase as well as at least one comparative phase. Of the initial 707 articles identified, 22 met the selection criteria and were included. The studies considered a total of 433 subjects. Our results revealed medium effects (weighted mean standardized mean difference () = 0.60; seven studies) for isometric maximal strength in favor of the late follicular phase, small effects (weighted mean = 0.39; five studies) for isokinetic maximal strength in favor of the ovulation phase, and small effects (weighted mean = 0.14; three studies) for dynamic maximal strength in favor of the late follicular phase. The results indicate that the early follicular phase is unfavorable for all strength classes. Peak performance in isometric strength is seen in the late follicular phase, whereas isokinetic strength peaks during ovulation. Dynamic strength is optimal in the late follicular phase.
PubMed: 38251305
DOI: 10.3390/sports12010031 -
Journal of Personalized Medicine Feb 2023The correlation between the menstrual cycle and glucose control in type 1 diabetes has been the focus of several studies since the 1920s, but a few critical aspects made... (Review)
Review
The correlation between the menstrual cycle and glucose control in type 1 diabetes has been the focus of several studies since the 1920s, but a few critical aspects made it particularly challenging to reach conclusive evidence. The aim of this systematic review is to reveal more solid information about the impact of the menstrual cycle on glycaemic outcomes and insulin sensitivity in type 1 diabetes and highlight the less researched areas. The literature was searched by two authors independently using PubMed/MEDLINE, Embase and Scopus (last search on 2 November 2022). The retrieved data did not allow us to perform a meta-analysis. We included 14 studies published between 1990 and 2022, with sample sizes from 4 to 124 patients. We found a wide heterogeneity in the definition of the menstrual cycle phases, glucose metrics, techniques for determining insulin sensitivity, hormonal assessment and other interfering factors considered, with an overall high risk of bias. There is no conclusive evidence, and published data do not allow us to achieve quantitative results. In a subset of patients, a possible worsening of insulin sensitivity and hyperglycaemia in the luteal phase could be observed. From the clinical standpoint, a cautious strategy based on patient-specific patterns can be considered until new, solid evidence is obtained.
PubMed: 36836608
DOI: 10.3390/jpm13020374 -
Reproductive Health Jun 2022Menstrual hygiene management (MHM) and practices by adolescent females of low and middle-income countries (LMICs) are a severe public health issue. The current... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Menstrual hygiene management (MHM) and practices by adolescent females of low and middle-income countries (LMICs) are a severe public health issue. The current systematic review and meta-analysis aimed to estimate the pooled proportion of the hygiene practices, menstrual problems with their associated factors, and the effectiveness of educational interventions on menstrual hygiene among adolescent school girls in India.
METHODS
PRISMA checklist and PICO guidelines were used to screen the scientific literature from 2011 to 2021. The Newcastle-Ottawa Scale was used to assess the quality of studies. Four themes were developed for data analysis, including hygiene practices, type of absorbent used, menstruation associated morbidities and interventions performed regarding menstruation. Eighty-four relevant studies were included and a meta-analysis, including subgroup analysis, was performed.
RESULTS
Pooled data revealed a statistically significant increase in sanitary pad usage "(SMD = 48.83, 95% CI = 41.38-57.62, p < 0.00001)" and increased perineum practices during menstruation "(SMD = 55.77, 95% CI = 44.27-70.26, p < 0.00001)". Results also reported that most prevalent disorders are dysmenorrhea "(SMD = 60.24, 95% CI = 50.41-70.06, p < 0.0001)", Pre-menstrual symptoms "(SMD = 62.67, 95% CI = 46.83-78.50, p < 0.00001)", Oligomenorrhea "(SMD = 23.57, CI = 18.05-29.10, p < 0.00001), Menorrhagia "(SMD = 25.67, CI = 3.86-47.47, p < 0.00001)", PCOS "(SMD = 5.50, CI = 0.60-10.40, p < 0.00001)", and Polymenorrhea "(SMD = 4.90, CI = 1.87-12.81, p < 0.0001)". A statistically significant improvement in knowledge "(SMD = 2.06, 95% CI = 0.75-3.36, p < 0.00001)" and practice "(SMD = 1.26, 95% CI = 0.13-2.65, p < 0.00001)" on menstruation was observed. Infections of the reproductive system and their repercussions can be avoided with better awareness and safe menstruation practices.
CONCLUSIONS
Learning about menstrual hygiene and health is essential for adolescent girls' health education to continue working and maintaining hygienic habits. Infections of the reproductive system and their repercussions can be avoided with better awareness and safe menstruation practices.
Topics: Adolescent; Female; Health Knowledge, Attitudes, Practice; Humans; Hygiene; India; Menstrual Hygiene Products; Menstruation; Schools
PubMed: 35739585
DOI: 10.1186/s12978-022-01453-3 -
Human Reproduction Update Sep 2023The number of frozen embryo transfers (FET) has increased dramatically over the past decade. Based on current evidence, there is no difference in pregnancy rates when... (Meta-Analysis)
Meta-Analysis
BACKGROUND
The number of frozen embryo transfers (FET) has increased dramatically over the past decade. Based on current evidence, there is no difference in pregnancy rates when natural cycle FET (NC-FET) is compared to artificial cycle FET (AC-FET) in subfertile women. However, NC-FET seems to be associated with lower risk of adverse obstetric and neonatal outcomes compared with AC-FET cycles. Currently, there is no consensus about whether NC-FET needs to be combined with luteal phase support (LPS) or not. The question of how to prepare the endometrium for FET has now gained even more importance and taken the dimension of safety into account as it should not simply be reduced to the basic question of effectiveness.
OBJECTIVE AND RATIONALE
The objective of this project was to determine whether NC-FET, with or without LPS, decreases the risk of adverse obstetric and neonatal outcomes compared with AC-FET.
SEARCH METHODS
A systematic review and meta-analysis was carried out. A literature search was performed using the following databases: CINAHL, EMBASE, and MEDLINE from inception to 10 October 2022. Observational studies, including cohort studies, and registries comparing obstetric and neonatal outcomes between singleton pregnancies after NC-FET and those after AC-FET were sought. Risk of bias was assessed using the ROBINS-I tool. The quality of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation approach. We calculated pooled odds ratios (ORs), pooled risk differences (RDs), pooled adjusted ORs, and prevalence estimates with 95% CI using a random effect model, while heterogeneity was assessed by the I2.
OUTCOMES
The conducted search identified 2436 studies, 890 duplicates were removed and 1546 studies were screened. Thirty studies (NC-FET n = 56 445; AC-FET n = 57 231) were included, 19 of which used LPS in NC-FET. Birthweight was lower following NC-FET versus AC-FET (mean difference 26.35 g; 95% CI 11.61-41.08, I2 = 63%). Furthermore NC-FET compared to AC-FET resulted in a lower risk of large for gestational age (OR 0.88, 95% 0.83-0.94, I2 = 54%), macrosomia (OR 0.81; 95% CI 0.71-0.93, I2 = 68%), low birthweight (OR 0.81, 95% CI 0.77-0.85, I2 = 41%), early pregnancy loss (OR 0.73; 95% CI 0.61-0.86, I2 = 70%), preterm birth (OR 0.80; 95% CI 0.75-0.85, I2 = 20%), very preterm birth (OR 0.66, 95% CI 0.53-0.84, I2 = 0%), hypertensive disorders of pregnancy (OR 0.60, 95% CI 0.50-0.65, I2 = 61%), pre-eclampsia (OR 0.50; 95% CI 0.42-0.60, I2 = 44%), placenta previa (OR 0.84, 95% CI 0.73-0.97, I2 = 0%), and postpartum hemorrhage (OR 0.43; 95% CI 0.38-0.48, I2 = 53%). Stratified analyses on LPS use in NC-FET suggested that, compared to AC-FET, NC-FET with LPS decreased preterm birth risk, while NC-FET without LPS did not (OR 0.75, 95% CI 0.70-0.81). LPS use did not modify the other outcomes. Heterogeneity varied from low to high, while quality of the evidence was very low to moderate.
WIDER IMPLICATIONS
This study confirms that NC-FET decreases the risk of adverse obstetric and neonatal outcomes compared with AC-FET. We estimate that for each adverse outcome, use of NC-FET may prevent 4 to 22 cases per 1000 women. Consequently, NC-FET should be the preferred treatment in women with ovulatory cycles undergoing FET. Based on very low quality of evidence, the risk of preterm birth be decreased when LPS is used in NC-FET compared to AC-FET. However, because of many uncertainties-the major being the debate about efficacy of the use of LPS-future research is needed on efficacy and safety of LPS and no recommendation can be made about the use of LPS.
Topics: Pregnancy; Infant, Newborn; Female; Humans; Birth Weight; Premature Birth; Luteal Phase; Lipopolysaccharides; Cryopreservation; Embryo Transfer; Pregnancy Rate; Retrospective Studies
PubMed: 37172270
DOI: 10.1093/humupd/dmad011