Effects of Yogic Breathing on Hypertensive Pregnancies

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Poster text:

Acute Physiological Effects of Yogic Breathing Techniques in Hypertensive Pregnancies

Shilpa Babbar, MD, MS, FACOG sbabbar@umn.edu
Katelyn Tessier, MS
Karen Williams, PhD

BACKGROUND
Pranayama (yogic breathing) has been shown to improve autonomic balance and lower blood pressure in hypertensive adults, supporting its role as a complementary non-pharmacologic therapy.

Despite the frequent recommendation of deep breathing practices during pregnancy, the hemodynamic effects and benefits of specific pranayama techniques in pregnancies complicated by hypertensive disorders remain unknown.

METHODS
Pilot randomized controlled trial

Participants:
31 pregnant individuals
≥28 weeks gestation
Chronic HTN, gestational HTN, or preeclampsia without severe features

Randomized to:
Alternate Nostril Breathing (ANB) (n=10)
Bhramari (humming bee) pranayama (n=11)
Sheetali (cooling) pranayama (n=10)

Each participant completed:
15 min baseline monitoring
15 min guided deep breathing (5 min epochs)
15 min post-intervention monitoring
Continuous physiologic data obtained using the VitalStream wearable hemodynamic monitor (BP, HR, RR) and Calera sensor (skin temp)

Mean differences in systolic blood pressure relative to pre-intervention

Time period	ANB ✧	Bhramari ✧	Sheetali ✧
Pre-intervention	Reference	Reference	Reference
Intervention epoch 1–5 min	0.81 (-6.11, 7.72)	11.6 (5.5, 17.7)	-1.9 (-7.5, 3.7)
Intervention epoch 6–10 min	3.65 (-3.26, 10.57)	14.3 (7.96, 20.7)	-2.7 (-8.3, 2.9)
Intervention epoch 11–15 min	3.24 (-3.68, 10.15)	12.8 (6.5, 19.0)	-2.0 (-7.6, 3.6)
Post-intervention	5.97 (-0.65, 12.59)	1.8 (-4.4, 8.0)	3.55 (0.16, 6.93)
P value	0.375	<0.001	0.003

✧ Mean difference (95% CI)

Mean differences in systolic blood pressure relative to pre-intervention

Time period	ANB ✧	Bhramari ✧	Sheetali ✧
Pre-intervention	Reference	Reference	Reference
Intervention epoch 1–5 min	0.44 (-2.29, 3.17)	5.6 (2.6, 8.6)	-0.5 (-3.2, 2.1)
Intervention epoch 6–10 min	1.38 (-1.35, 4.11)	7.13 (3.9, 10.36)	-0.9 (-3.6, 1.8)
Intervention epoch 11–15 min	0.89 (-1.84, 3.62)	6.0 (2.8, 9.2)	-0.4 (-3.1, 2.3)
Post-intervention	2.32 (-0.29, 4.93)	1.1 (-2.1, 4.3)	1.93 (0.05, 3.82)
P value	0.425	<0.001	0.014

✧ Mean difference (95% CI)

Participant acceptability & perceived effects (n = 31)
100% – Breathing exercise easy to learn
94% – Reported feeling different after the intervention
↳90% – Felt relaxed or calm after breathing
94% – Believed breathing may benefit their pregnancy
94% – Plan to continue practicing during pregnancy

Characteristic	All subjects (N=31)	ANB (N=10)	Bhramari (N=11)	Sheetali (N=10)	P-value
Maternal age (years)	33.9 ±4.3	33.5 ±5.3	35.2 ±4.4	32.9 ±2.5	0.334
Gestational age at testing (weeks)	32.3 ±3.5	33.1 ±2.2	31.6 ±4.4	32.4 ±3.4	0.794
Nulliparous, n (%)	12 (40.0)	4 (40.0)	5 (45.5)	3 (33.3)	0.899
Race, n (%)					0.467
White or European descent	23 (79.3)	7 (77.8)	7 (63.6)	9 (100.0)
Black or African descent	4 (13.8)	2 (22.2)	2 (18.2)	0 (0.0)
Mixed race	1 (3.4)	0 (0.0)	1 (9.1)	0 (0.0)
Other	1 (3.4)	0 (0.0)	1 (9.1)	0 (0.0)
Hispanic ethnicity, n (%)	2 (6.9)	0 (0.0)	2 (18.2)	0 (0.0)	0.313
Marital status, n (%)					0.494
Married / living with partner	23 (76.7)	8 (80.0)	7 (63.6)	8 (88.9)
Never married	7 (23.3)	2 (20.0)	4 (36.4)	1 (11.1)
Educational level, n (%)					0.501
College graduate	19 (63.3)	6 (60.0)	6 (54.5)	7 (77.8)
Some college	5 (16.7)	1 (10.0)	2 (18.2)	2 (22.2)
High school graduate	6 (20.0)	3 (30.0)	3 (27.3)	0 (0.0)
Diabetes, n (%)					0.378
Gestational	7 (22.6)	3 (30.0)	3 (27.3)	1 (10.0)
Type I	1 (3.2)	0 (0.0)	0 (0.0)	1 (10.0)
Type II	2 (6.5)	0 (0.0)	2 (18.2)	0 (0.0)
Hypertensive diagnosis, n (%)
Chronic hypertension	18 (58.0)	4 (40.0)	7 (63.6)	7 (70.0)
Gestational hypertension	8 (25.8)	2 (20.0)	4 (36.4)	2 (20.0)
Pre-eclampsia without severe features	5 (16.2)	4 (40.0)	0 (0.0)	1 (10.0)

Data presented as Mean ±SD or n (%)

Changes in respiratory and autonomic markers by technique

Outcome	Technique	Pre-intervention Mean (SD)	Intervention vs pre-intervention ✧	Post-intervention vs pre-intervention ✧	P value
Respiratory rate (per min)	ANB	14.7 (2.0)	−3.1(−4.6, −1.6)	−1.0 (−2.5, 0.5)	<0.001
	Bhramari	15.2 (1.6)	−3.3 (−4.8, −1.8)	−0.9 (−2.3, 0.6)	<0.001
	Sheetali	14.4 (2.2)	−1.8 (−3.2, −0.4)	−0.6 (−2.0, 0.8)	0.017
Skin temp. (°C)	ANB	32.5 (1.4)	0.8 (0.3, 1.2)	1 (0.6, 1.4)	<0.001
	Bhramari	32.2 (1.5)	0.8 (0.4, 1.3)	1.1 (0.6, 1.5)	<0.001
	Sheetali	31.7 (1.4)	1.2 (0.6, 1.7)	1.4 (0.9, 2.0)	<0.001
Heart rate (bpm)	ANB	91.4 (6.8)	2.4 (-0.9, 5.7)	3.3 (-0.01, 6.6)	0.093
	Bhramari	89.1 (6.7)	2.6 (0.4, 4.8)	0.5 (-1.7, 2.7)	0.033
	Sheetali	89.1 (13.1)	0.3 (-2.3, 2.8)	-1.7 (-4.3, 0.9)	0.210

Data presented as Mean ±SD or n (%)

CONCLUSION

Pranayama techniques produced distinct hemodynamic responses in hypertensive pregnancies.

ANB: Slowed breathing without significant hemodynamic change.

Bhramari: Produced a pressor response with increased blood pressure, heart rate, and skin temperature.

Sheetali: Produced a transient reduction in blood pressure despite increased skin temperature.

These findings suggest technique-specific autonomic effects and support further investigation of pranayama as a potential adjunctive therapy in hypertensive pregnancy.