Effect of Yoga in Pregnancy on Cardio-respiratory Adaptation to Challenge (YOGADAPT)

University Medical Centre Ljubljana

Status: Completed

Conditions: Autonomic Nervous System; Pregnancy; Yoga

Treatments: Other: walk; Other: weekly yoga classes

Study type: Interventional

Funder types: Other

Identifiers

NCT04476368

0120-575/2018/5

Details and patient eligibility

About

Yoga has received considerable attention for its potential therapeutic benefits over the past decades and it gradually became object of scientific scrutiny. There is currently extensive literature supporting its use as a non-pharmacological tool for managing a variety of medical problems. A few studies have also explored potential beneficial effects of practising yoga during pregnancy on maternal and neonatal outcomes. An association between prenatal yoga and decreased incidence of fetal growth restriction, preterm delivery, and labor abnormalities resulting in operative delivery have been reported.

Exact mechanisms by which yoga could improve perinatal outcomes have not been elucidated yet. One of such mechanisms could be the positive effect of yoga on autonomic nervous system (ANS). Maternal cardiovascular system undergoes profound changes during pregnancy and ANS plays a central role in adaptation to pregnancy-related hemodynamic changes. Increase in peripheral vascular resistance that characterises hypertensive disorders in pregnancy with fetal growth restriction is mediated by substantial increase in sympathetic vasoconstrictor activity. Effects of yoga on ANS outside of pregnancy have already been investigated in several studies. Heart rate variability (HRV) indices, used as a one of proxy measures for ANS activity, showed significant shifts towards parasympathetic dominance following yoga sessions. Another objective means of assessing ANS activity is measurement of phase synchronisation between cardiovascular and respiratory systems following acute challenge. The higher the cardiorespiratory synchronisation after acute challenge is, the higher is the ability of ANS to flexibly adapt to challenge.

The objectives of the study are:

I. To examine whether there is a short-term shift in autonomic balance to the parasympathetic branch of the ANS and ability of the cardiovascular and respiratory respiratory systems to flexibly adapt to acute psychological challenge following sessions in pregnancy.

II. To investigate potential long- term effects of yoga practice during pregnancy on HRV and cardio-respiratory synchronisation following acute psychological challenge.

Enrollment: 100 patients

Sex: Female

Ages: 18 to 40 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Healthy pregnant women with singleton pregnancies.

Exclusion criteria

• Multiple pregnancies
• Cardiovascular disease (including hypertension and arrhythmias)
• Taking medications that would affect heart rate or blood pressure
• Psychiatric disorders
• Epilepsy
• Kidney disease
• Liver disease
• Known fetal anomaly
• Autoimmune disorders
• Thyroid disease
• Diabetes mellitus
• Alcohol/drug abuse

Trial design

Primary purpose: Basic Science

Allocation: Non-Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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100 participants in 2 patient groups

yoga

Experimental group

Description:

Participants in yoga group will be recruited during prenatal yoga classes at two locations: Maribor and Ljubljana. Women will be instructed to attend one class per week. Classes will consist of pregnancy-adapted yoga practices according to the system Yoga in Daily Life. They will be 90 min in duration and will consist of initial relaxation (10 to 15 min), followed by yoga postures (asanas) and stretching exercises (45 to 60 min), and final breathing (pranayama), concentration (dharana), and meditation (dhyana) techniques (20 to 30 min). Two certified yoga instructors will lead yoga classes. Measurements will be performed before and after yoga session.

Treatment:

Other: weekly yoga classes

control

Active Comparator group

Description:

Control group will consist of healthy pregnant women attending regular prenatal visits at the departments of perinatology of the university medical centers Maribor and Ljubljana. Only women not attending any formal prenatal exercise program will be offered entrance in the study. Measurements in this group will be performed before and after a 20-30 minute walk.

Treatment:

Other: walk