A new study, “The Effects of Yoga in Prevention of Pregnancy Complications in High-Risk Pregnancies: A Randomized Controlled Trial,” conducted by SVYASA University’s Department of Life Sciences in Bengaluru, India just came out last month. The information gathered by the researchers was fascinating and may prove to be very helpful for a lot of high-risk pregnant women.
The study included 68 high-risk pregnant women who were recruited from two maternity hospitals in Bengaluru, India and were randomized into two groups: yoga and control. The yoga group received standard care plus one-hour yoga sessions, 3 times per week (28 sessions in all) primarily during their 2nd and beginning of their 3rd trimester. The yoga class was focused on asanas (poses), pranayama (breathing exercises), visualization, guided imagery, and savasana (deep relaxation). There was also instruction on how to “rest with awareness”. The control group received standard care plus conventional antenatal exercises (walking) during the same period.
The results did highlight very positive results for the yoga group in comparison to the control group. The primary result seen was that the maternal blood pressure was lower. The secondary result had to do with the maternal stress rate. There was measurable improvement with the Heart Rate Variability (HRV) as well as the perceived lowering of stress from the pregnant mother’s point of view (1). The study showed significantly fewer pregnancy with induced hypertension (PIH), preeclampsia, gestational diabetes (GDM) and intrauterine growth restriction (IUGR) cases in the yoga group. There were also significantly fewer Small for Gestational Age (SGA) babies and newborns with low APGAR scores in the yoga group, as well as significantly fewer cases of preterm deliveries, which are all prevalent birth issues in India.
UNDERSTANDING THE RESULTS
The etiology of these complications mentioned above is not clearly understood; however, there is increasing evidence that maternal oxidative stress and psychological stress play a strong role (2). Numerous studies have already proven the remarkable effects yoga has on reducing stress. Stress elevates the heart rate and blood pressure and triggers the sympathetic nervous system. A study out of Harvard University states that “Yoga has been shown to reduce the heart rate, lower blood pressure, and ease respiration. There is also evidence that yoga practices help increase heart rate variability, an indicator of the body’s ability to respond to stress more flexibly” (3). Recent studies have also shown yoga to be effective in reducing oxidative and psychological stress” (4).
The India study goes on to further discuss their findings: “The reduction in the maternal stress could also have:
1) fostered multiple positive downstream effects on neuroendocrine pathway, metabolic function, and associated inflammatory responses
2) activated the vagal nerve and thereby improved parasympathetic output leading to enhanced cardiac-vagal function, mood, energy state, and related neuroendocrine, metabolic, and inflammatory responses and/or
3) promoted a feeling of well-being, perhaps by reducing the activation and reactivity of the sympathoadrenal system and the hypothalamic pituitary adrenal (HPA) axis.”
If stress reduction and lowering of maternal blood pressure were the significant results from the yoga practice, it is logical the three significant complications, preeclampsia, gestational diabetes (GDM) and intrauterine growth restriction (IUGR), showed improvement. Below are some basic notes on these three aforementioned conditions:
Preeclampsia is when a pregnant women develops high blood pressure and has protein in her urine after 20 weeks gestation. Preeclampsia can be controlled, but the only “cure” for it is to deliver the baby. The study we are looking at concluded that the primary outcome was that maternal blood pressure was lower through the yoga practice, which can explain the decrease in preeclampsia in the yoga group.
Gestational diabetes is a condition in which the glucose level is elevated and other diabetic symptoms appear during pregnancy in a woman who has not previously been diagnosed with diabetes. All diabetic symptoms disappear following delivery (5). There is a direct correlation between stress and elevated blood sugar levels. Again, we refer back to yoga’s ability to help lower both the oxidative stress level and the perceive stress level to help control this condition.
Intrauterine growth restriction (IUGR) is a when the baby is under the 10th percentile of weight for their gestational age while in the womb. There are many factors that could contribute to IUGR, some include, preeclampsia, hypertension, diabetes, abnormal placentation and cardiovascular disease. It is not a far jump to think the reason IUGR numbers where decreased among the yoga group, was because there were significant improvements seen with the possible causing factor. While management of IUGR must be individualized for each patient. One management treatment, although not of proven benefit, is bed rest which may maximize uterine blood flow (6). Again, we see the benefit of yoga here. Yoga increases blood flow which can maximize blood flow to the placenta. Decreasing maternal blood pressure dilates the blood vessels, also allowing for better blood flow to the uterus.
Interestingly, the “standard antenatal practice” for these high-risk issues would have included medication, bed rest and walking. Positive results were obtained instead from a 3x per week yoga practice.
This first randomized study of yoga in high-risk pregnancy has shown that yoga can potentially be an effective therapy in reducing hypertensive related complications of pregnancy and improving fetal outcomes. Additional data is needed to confirm these results and better explain the mechanism of action of yoga in this important area (7).
Even though there has now been research supporting yoga as a practice for high-risk women, it is still best to check with your care provider before starting a yoga class.