The trial will be conducted as a pilot study in one study visit, which will be conducted in two phases. Phase I will be conducted on normotensive pregnant women and Phase II will be conducted on hypertensive pregnant women. Participants will be in their third trimester of pregnancy (28 weeks onwards).~Upon presentation, they will be randomized into one of three groups: Alternate nostril breathing, Bhramari breathing or Sheetali breathing. Maternal monitoring devices will be placed on the patient before the intervention. The fetus will be monitored by external monitors consisting of a fetal heart rate monitor and tocodynamometer to assess uterine activity. Fetal position will be assessed before and after the intervention by ultrasound. All devices will obtain a reading for 15 minutes before, during and after the intervention.~Intervention: In an upright, seated position, the participant will engage in a total of 15 minutes of one deep breathing technique. The breathing practice will be conducted in three, 5-minute increments with a one-minute break between each session. These breathing techniques are easy to learn and participants will be taught how to perform the exercise (visual demonstration, verbal and written instructions will be provided). Participants will be given the opportunity to practice the breathing technique and ask any questions prior to initiating monitoring.
Slow deep breathing actives the vagal nerve and leads to a natural reduction in physiological parameters such as blood pressure, heart rate and digestion. The effects of these techniques have not been assessed in pregnancy. The primary objective is to assess the effects of various yogic deep breathing techniques on blood pressure during pregnancy. The breathing exercises will include Alternate nostril breathing, Bhramari breathing, and Sheetali breathing. A secondary objective will be to assess the effects of these breathing exercises on other physiological parameters including heart rate, heart rate variability, body temperature, cardiac output, vascular resistance and respiratory rate.