Can Maternal Relaxation Techniques Impact Fetus Well-Being?

February 21, 2011

Modern medicine recognizes the potential impact of stress on physical well-being, but can stress pass through the mother to the fetus? Indeed, it has been hypothesized that maternal chronic stress can alter the uterine environment and may affect length of gestation, fetal growth, birth weight, and spontaneous preterm birth. Similarly, research on cortisol levels in fetuses and mothers has found that anxiety in mothers can affect the function of the placenta. With so much evidence pointing to the interaction between maternal psychological well-being and fetal wellness, there has become an increased need to find effective, nonpharmacological interventions for pregnant women.

Modern medicine recognizes the potential impact of stress on physical well-being, but can stress pass through the mother to the fetus? Indeed, it has been hypothesized that maternal chronic stress can alter the uterine environment and may affect length of gestation, fetal growth, birth weight, and spontaneous preterm birth. Similarly, research on cortisol levels in fetuses and mothers has found that anxiety in mothers can affect the function of the placenta. With so much evidence pointing to the interaction between maternal psychological well-being and fetal wellness, there has become an increased need to find effective, nonpharmacological interventions for pregnant women. In the first study of its kind, Dr Nadine S Fink, Department of Developmental Pediatrics, Children's Hospital Boston, Harvard Medical School, and colleagues investigated the effects of maternal relaxation techniques on fetal behavior and uterine activity. The participants included 39 women 18 years and older who were pregnant with a single, healthy fetus between the 32nd and 34th weeks of pregnancy. Women were randomized to receive 10-minute intervention (progressive muscle relaxation [N = 13] or guided imagery [N = 13]) or quiet rest (control [N = 13]). Saliva and blood samples were collected to measure cortisol and norepinephrine levels, respectively, prior to the rest/intervention cycle as well as immediately following the intervention, 10 minutes following the intervention, and 20 minutes post-intervention. Blood pressure and heart rate was also measured at all intervals. A study midwife used cardiotocogram to assess fetal parameters and uterine activity. According to the data, fetuses whose mothers were in one of the intervention groups displayed greater fetal heart rate variation than those in the control group. Furthermore, those in the guided imagery group had higher short-term fetal heart rate variation compared to those in the progressive muscle relaxation group. Since greater fetal heart rate variation is often associated with fetal well-being, the increased variation implied possible effectiveness of the interventions. Fetuses in the guided imagery group also had more fetal body movements compared to those in the other intervention group. The researchers relate this finding to reports from women who noted an increase in fetal movement when they reclined, although it previously was unclear if this was enhanced perception or reality. However, the researchers believe their finding supports this notion. They noted, “Our results regarding GI and fetal movement suggest that mothers are really ‘feeling’ their children.” Increased uterine activity was found in patients in the progressive muscle relaxation as compared to those in the guided imagery group. Since the increased sensations could worry a patient, the researchers do not recommend progressive muscle relation in those patients with high perception of body sensations. Similarly, since the effects of progressive muscle relaxation on women with early uterine activity/contractions is unclear, the researchers suggest avoiding this relaxation technique in this subgroup of patients. Despite previous research findings, Fink and colleagues did not find any correlations between maternal heart rate, maternal blood pressure, or cortisol and norepinephrine with fetal behavior. Thus, they believe further research is needed into the mechanistic explanations of maternal-fetal communication during relaxation exercises. Ultimately, the researchers believe this study further emphasizes the importance of addressing stress in pregnant women. “Screening for maternal distress and mood disturbances during pregnancy should be recommended,” they concluded. “Affected mothers should be offered treatment with the aim to increase well-being, to optimize obstetric outcome and hence fetal development.” More Information


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Reference

 Fink NS, Urech C, Isabel F, et al.

Fetal response to abbreviated relaxation techniques. A randomized controlled study

Early Hum Dev

. 2011;87(2):121-127.