The characteristics and effectiveness of pregnancy yoga interventions: a systematic review and meta-analysis

Background

Yoga is a popular mind-body medicine frequently recommended to pregnant women. Gaps remain in our understanding of the core components of effective pregnancy yoga programmes. This systematic review and meta-analysis examined the characteristics and effectiveness of pregnancy yoga interventions, incorporating the FITT (frequency, intensity, time/duration and type) principle of exercise prescription.

Methods

Nine electronic databases were searched: MEDLINE, PsycINFO, EMBASE, CINAHL, WHOLiS, AMED, ScieLo, ASSIA and Web of Science. Randomised control trials and quasi-experimental studies examining pregnancy yoga interventions were eligible. Covidence was used to screen titles, abstracts, and full-text articles. Outcomes of interest were stress, anxiety, depression, quality of life, labour duration, pain management in labour and mode of birth. The Cochrane Collaboration’s Risk of Bias Assessment tool was used to assess methodological quality of studies and GRADE criteria (GRADEpro) evaluated quality of the evidence. Meta-analysis was performed using RevMan 5.3.

Results

Of 862 citations retrieved, 31 studies met inclusion criteria. Twenty-nine studies with 2217 pregnant women were included for meta-analysis. Pregnancy yoga interventions reduced anxiety (SMD: -0.91; 95% CI: − 1.49 to − 0.33; p = 0.002), depression (SMD: -0.47; 95% CI: − 0.9 to − 0.04, P = 0.03) and perceived stress (SMD: -1.03; 95% CI: − 1.55 to − 0.52; p < 0.001). Yoga interventions also reduced duration of labour (MD = − 117.75; 95% CI − 153.80 to − 81.71, p < 0.001) and, increased odds of normal vaginal birth (OR 2.58; 95% CI 1.46–4.56, p < 0.001) and tolerance for pain. The quality of evidence (GRADE criteria) was low to very low for all outcomes. Twelve or more yoga sessions delivered weekly/bi-weekly had a statistically significant impact on mode of birth, while 12 or more yoga sessions of long duration (> 60 min) had a statistically significant impact on perceived stress.

Conclusion

The evidence highlights positive effects of pregnancy yoga on anxiety, depression, perceived stress, mode of birth and duration of labour.

Systematic review registration: PROSPERO, CRD42019119916. Registered on 11th January 2019.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04474-9.

Hypertension in pregnancy: Prevalence, risk factors and outcomes for women birthing in Ireland

OBJECTIVES

The purpose of this study was to identify the number of pregnancies affected by hypertension in Ireland and report on possible risk factors and adverse pregnancy outcomes for women and their babies.

STUDY DESIGN

Data on maternity hospital discharges for women giving birth in Ireland in 2016 were extracted from the national Hospital In-Patient Enquiry data system. Women with a diagnosis of a hypertensive disorder of pregnancy were identified using relevant ICD codes. Descriptive statistics were used to present prevalence, and Pearson's Chi-square and multivariable regression analyses were conducted to identify risk factors and pregnancy outcomes. Differences between proportions were analysed by Pearson's Chi-squared test of independence.

RESULTS

Of 60,188 maternities reported for the year 2016, 5.9% of women (n = 3531) had a hypertensive disorder of pregnancy and 4.6% (n = 2790) had pre-eclampsia. Rates were higher among women with pre-existing diabetes, gestational diabetes, obesity and those aged ≥40 years. After adjusting for maternal age, pre-existing DM, GDM, obesity and tobacco use, obesity (AOR 4.3; 95% CI: 3.2-5.7; p < 0.001), pre-existing diabetes (AOR 3.5; 95% CI: 2.5-4-9; p < 0.001), gestational diabetes (AOR 1.5; 95% CI: 1.3-1.8; p < 0.001) and being aged ≥40 years (AOR 1.5; 95% CI: 1.3-1.7; p < 0.001) remained significantly associated with being diagnosed with a hypertensive disorder of pregnancy in the Republic of Ireland.

CONCLUSION

In Ireland where maternal age at childbirth is increasing, the association of hypertension with advancing age will undoubtedly contribute to a greater prevalence of hypertensive disorders of pregnancy and their potential adverse outcomes for pregnant women and their babies. This retrospective study highlights the prevalence rates in Ireland while also identifying possible risk factors and associated adverse pregnancy outcomes. They pinpoint the need for further research to look in more detail at risk factors and adverse outcomes for the 79% (n = 2790) of women presenting with pre-eclampsia among this large nationally representative sample of women.

The effectiveness and characteristics of pregnancy yoga interventions: a systematic review protocol

Background: The purpose of this review is to systematically examine the reported clinical effectiveness of pregnancy yoga.  The review will use the FITT (frequency, intensity, time/duration and type) principle of physical activity to characterise the different types of yoga interventions that have been evaluated in the included studies.  Studies will be categorised as effectiveness or efficacy studies and this continuum of efficacy versus effectiveness will be incorporated into the full review.  Methods/design: The following electronic databases will be searched using a detailed search strategy: MEDLINE, PsycINFO, EMBASE, CINAHL, WHOLiS, AMED, ScieLo, ASSIA and Web of Science. Randomised control trials and quasi-experimental studies examining pregnancy yoga and reporting on effect will be included. Titles, abstracts and full articles will be screened by two investigators independently to identify eligible studies.  The Cochrane Collaboration's Risk of Bias Assessment tool will be used to assess study quality.  Quality of the evidence will be evaluated using the GRADE criteria. A standardised data extraction form will be used to extract data. Effect sizes will be estimated using mean differences for continuous outcomes, and relative risks for dichotomous outcome. Where possible, pooling of effect estimates will be done using a random effect model.  The outcomes of interest are quality of life, stress, anxiety, depression, mode of birth, labour duration and pain management in labour. Discussion: This review will synthesise the best available evidence on the effectiveness of yoga during pregnancy and provide valuable high-quality information for clinicians and health policymakers. Findings will be disseminated through publication in a peer-reviewed journal and presentation at relevant conference proceedings. The review will make recommendations for the appropriate volume, intensity and type of pregnancy yoga for maximum effect and may have implications for policy and practice relating to pregnancy yoga as an intervention.   Registration: PROSPERO, CRD42019119916.  Registered on 11th January 2019.

The effectiveness and characteristics of pregnancy yoga interventions: a systematic review protocol

Background: The purpose of the proposed review is to systematically examine the clinical effectiveness of pregnancy yoga.  The review will use the FITT (frequency, intensity, time/duration and type) principle of physical activity to characterise the different types of yoga interventions that have been evaluated in the included studies.   Methods/design: The following electronic databases will be searched using a detailed search strategy: MEDLINE, PsycINFO, EMBASE, CINAHL, WHOLiS, AMED, ScieLo, ASSIA and Web of Science. Randomised control trials and quasi-experimental studies examining pregnancy yoga will be included. Titles, abstracts and full articles will be screened by two investigators independently to identify eligible studies.  The Cochrane Collaboration's Risk of Bias Assessment tool will be used to assess study quality.  Quality of the evidence will be evaluated using the GRADE criteria. A standardised data extraction form will be used to extract data. Effect sizes will be estimated using mean differences for continuous outcomes, and relative risks for dichotomous outcome. Where possible, pooling of effect estimates will be done using a random effect model. Discussion: This review will synthesise the best available evidence on the effectiveness of yoga during pregnancy and provide valuable high-quality information for clinicians and health policymakers. Findings will be disseminated through publication in a peer-reviewed journal and presentation at relevant conference proceedings. The review will make recommendations for the appropriate volume, intensity and type of pregnancy yoga for maximum effect and may have implications for policy and practice relating to pregnancy yoga as an intervention.   Registration: PROSPERO, CRD42019119916.  Registered on 11th January 2019.

Bone strength index in adolescent girls: does physical activity make a difference?

BACKGROUND

Bone strength index (BSI) combines bone mineral and bone biomechanical properties to measure resistance to bending. This index may have greater clinical significance than the more often described markers of bone mineral content (BMC), areal density, or geometry alone and, in turn, may show a stronger relation to fracture risk. The BSI is the product of volumetric cortical bone mineral density (BMD) and cross sectional moment of inertia within a region of interest. Calculations combine dual energy x ray absorptiometry and magnetic resonance imaging technologies and provide a useful, non-invasive measure of in vivo bone strength.

OBJECTIVES

(a) To compare BSI in adolescent female middle distance runners and age matched controls; (b) to examine factors predictive of BSI in adolescent girls.

METHODS

Twenty adolescent female middle distance runners (mean (SD) age 16 (1.7) years, physical activity 8.9 (2.1) hours a week) and 20 female controls (age 16 (1.8) years, physical activity 2.0 (0.07) hours a week) were recruited. To calculate BSI, a region of interest representing 10% of the mid-distal tibia was analysed for dual energy x ray absorptiometry derived BMC and was combined with bone geometry and biomechanical properties obtained by magnetic resonance imaging assessments. Potential predictors of BSI were also examined.

RESULTS

Independent t tests showed that BMC (p = 0.028), cortical bone volume (p = 0.002), volumetric cortical BMD (p = 0.004), cross sectional moments of inertia (p = 0.005), and BSI (p = 0.002) were higher in the distal tibia of athletes than of controls. The strongest predictor of BSI was hours of physical activity a week (R2 = 0.46).

CONCLUSIONS

Athletes habitually exposed to high training loads displayed greater BSI at the distal tibia than controls. The results further confirm BSI as a significant and discerning marker in musculoskeletal health in adolescent girls engaged in high and low mechanical loading.