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

Background: Yoga is a popular mind-body medicine frequently recommended and to pregnant women. Gaps remain in our understanding of core components of effective pregnancy yoga programmes. This review and meta-analysis examined the characteristics and effectiveness of pregnancy yoga, incorporating the FITT (frequency, intensity, time/duration and type) principle of exercise prescription in the analysis. Methods: : The following 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 for inclusion. 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: : 678 citations were retrieved, 24 studies met inclusion criteria. 22 studies with 1826 pregnant women were included for meta-analysis. Applying per-protocol analysis and a random effects model, the pooled standardised mean difference (SMD) for depression (-0.53; 95% CI: -1.04 to -0.02, P=0.04), anxiety (-0.82; 95% CI: -1.64 to -0.01; p=0.05), perceived stress (-1.03; 95% CI: -1.55 to -0.52; p<0.0001) and physiological stress (-0.24; 95% CI: -0.52 to 0.04, P=0.09) supported a statistically significant beneficial effect of pregnancy yoga interventions for anxiety, depression and perceived stress. Duration of labour was shorter (MD= -116.96; 95% CI -163.36 to -70.56, P<0.00001) and normal vaginal birth rates were higher in the yoga group (OR 2.72; 95% CI 1.26-5.90, p =0.01). The quality of evidence (GRADE) was low to very low for all factors. Twelve or more yoga sessions delivered weekly/bi-weekly had a statistically significant impact on mode of birth, while twelve or more yoga sessions of long duration (>60mins) had a statistically significant impact on perceived stress. Yoga sessions had a statistically significant impact on anxiety while yoga therapy had a statistically significant impact on depression Conclusion: The evidence supports previously cited positive effects of pregnancy yoga on anxiety, depression, perceived stress, normal vaginal birth and shorter duration of labour. Systematic review registration: PROSPERO, CRD42019119916. Registered on 11 th January 2019.Protocol publication: Corrigan L, Eustace-Cook J, Moran P and Daly D. The effectiveness and characteristics of pregnancy yoga interventions: a systematic review protocol [version 2; peer review: 2 approved]. HRB Open Res 2020, 2 33 (https://doi.org/10.12688/hrbopenres.12967.2)