Effect of Music-Based Interventions on Maternal and Fetal Parameters during Pregnancy: A Systematic Review

Music is one of the non-pharmacological methods used to reduce stress, anxiety, and pain, as well as to improve the quality of life [1‒3]. An important effect of music is related to its impact on stress [4, 5]. Due to its easy accessibility, applicability, and cost-effectiveness, its efficacy has been frequently studied in different populations [6‒8]. It is frequently used during pregnancy and childbirth as one of the non-pharmacological methods [9‒12]. Hormonal and physiological changes that occur during pregnancy can affect the well-being of both the mother and the baby. Stress experienced during the prenatal period has been associated with high levels of cortisol, which can have negative effects on both the mother and the fetus [13, 14]. During this period, listening to music may have a therapeutic effect on reducing stress, thereby promoting the health of both the mother and baby. The effects of music on stress, anxiety, depression, blood pressure, and sleep quality during the antenatal period have been frequently studied [10, 15, 16]. In addition, its impact on fetal well-being parameters such as basal heart rate and fetal movements has been researched [17‒19].

Previous systematic reviews examining the effects of music on maternal and fetal health parameters have focused on specific outcomes related to maternal psychological health, such as stress and anxiety [9, 10]. However, the impact of music on maternal physiological parameters and fetal parameters has not been comprehensively addressed. Considering that stress management can affect physiological parameters, examining the effects of music on both physiological and psychological health parameters can help better understand its mechanism of action [20]. Specific factors that would help determine the influence of music therapy during pregnancy, such as the mother’s overall health status (medically low-risk pregnancy or high-risk pregnancy) and the characteristics of the music intervention (duration, frequency, etc.), are critical subjects of our literature investigation. This systematic review aimed to conduct a more comprehensive literature search on the effects of music on maternal and fetal parameters and to summarize the findings. This systematic review comprehensively explores the participants, outcomes, and characteristics of the intervention.

This review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines [21]. The study protocol was prospectively registered in the PROSPERO database (ID = CRD42018102914).

We conducted a comprehensive search of clinical trials reported from January 1, 2008, to January 1, 2019, across in multiple databases, including PubMed, ScienceDirect, Scopus, Web of Science, MEDLINE, CINAHL, Cochrane, ProQuest, and Turkish databases. Only studies published in English or Turkish were included in the review. Studies were selected based on the criteria described in the Population, Intervention, Comparison, and Outcome (PICO) format. The library team provided support in forming keywords and screening databases. The retrieved studies were evaluated in terms of outcomes of interest (stress, anxiety, depression, sleep quality, blood pressure, fetal movement, fetal basal heart rate, acceleration) and study designs (randomized controlled trials [RCTs], quasi-experimental).

The inclusion criteria for the review were determined using the Population, Intervention, Comparison, Outcomes, and Study Design (PICOS) structure. The inclusion criteria were (1) population: pregnant women; (2) intervention: music-based interventions; (3) comparison: control group (no music intervention or routine care); (4) outcomes: maternal parameters (stress, anxiety, depression, blood pressure, sleep quality) and fetal parameters (basal fetal heart rate, acceleration, fetal movement); (5) study design: RCT or quasi-experimental studies published in English or Turkish. Exclusion criteria were as follows: (1) unavailable full text, (2) studies that compared music interventions without a control group, (3) poster presentations, conference papers, and study protocols.

First, duplicate articles were removed from the study. Two independent authors checked the titles and abstracts against inclusion and exclusion criteria. Two independent authors reviewed the full texts of all accessed studies meeting eligibility criteria (BA, DKT). If conflicts arose, they were rechecked by a third author (ADG) and subsequently discussed with the research team to reach a consensus. EndNote X8 was used in the study selection process.

Data extraction was performed by two independent authors (BA and DKT). Disagreements were resolved through discussion with a third reviewer. The following data were extracted: author, year of publication, study design and sample size, population characteristics, characteristics of intervention, and outcomes. The Music-based Intervention Reporting Guidelines were used to classify music interventions [22]. Two authors (BA and DKT) evaluated methodological quality using the Quality Assessment Tool for Quantitative Studies (QATQS) [23, 24]. This quality assessment tool evaluates studies according to selection bias, study design, confounders, blinding, data collection method, withdrawals, and dropouts. The quality score of each area (strong, moderate, weak) is evaluated, and an overall score is assigned to each study. In general, a study is scored “low” if there are two or more weak ratings, “moderate” if there is one weak rating, and “strong” if there are no weak ratings.

We screened 366 records after the removal of duplicates. Twenty-nine full-text studies were assessed for eligibility. After evaluating the inclusion and exclusion criteria for full-text studies, 13 were selected for analysis (shown in Fig. 1).

The characteristics of the 13 studies are shown in Table 1. These studies included 11 RCTs [15‒18, 25‒31] and two quasi-experimental trials [32, 33]. Only three studies included high-risk pregnant women who were hospitalized due to obstetric health problems, including preeclampsia, threatened preterm birth, premature rupture of membranes, and placenta previa bleeding [15, 26, 31], while the other ten studies consisted of low-risk pregnant women. Some studies specifically included low-risk pregnant women with specific complaints such as low back pain [25], anxiety [32], and sleep disorders [16].

The 13 studies in the review reported on four different types of music interventions: music listening (preselected by the investigator or selected by the participant from categories) [15‒18, 27‒29, 31‒33], music-facilitated relaxation [26], progressive muscle relaxation exercises accompanied with music [25], and composing a lullaby and listening to recorded lullaby [30]. Researchers commonly preferred 30-min music interventions, while the frequency of the intervention varied depending on the population and outcomes.

In this review, the methodological quality of the studies was evaluated by independent authors using the QATQS, and 13 studies were included in the review [23, 24]. As the studies are not community-based experimental trials, it is anticipated that they might be susceptible to “selection bias,” which pertains to issues of random selection. Since all these studies were hospital-based studies, the “study design” aspect, which evaluates random assignment in the quality assessment, becomes a crucial determinant of the studies’ overall quality. Therefore, this criterion was taken into consideration in the selection of the studies. The studies selected in the quality assessment exhibited significant shortcomings in terms of blinding. Nine studies were categorized as low quality, and three as moderate quality. Thirteen studies were identified as having strong quality in “data collection methods,” 12 in “study design” and “confounders,” and 10 in “withdrawals and dropouts” (Table 2). When the population in these studies was examined, it was found that some included women with high-risk pregnancies, while others focused on those with low-risk pregnancies. Overall, the population showed considerable diversity. Consequently, this systematic review faces challenges in generalizability since establishing clear links between specific pregnant populations and the influence of music becomes difficult.

The effect of music on maternal psychological health was evaluated with stress, anxiety, and depression outcomes. Studies examining the effect of music on mental health or psychological distress were also included.

The studies discussed the effect of prenatal music-based interventions on stress under two headings: general perceived stress and pregnancy-related stress. All the studies evaluating the general effect of music on stress included low-risk pregnant women [16, 27, 28, 30]. Specifically, one study sample consisted of low-risk pregnant women suffering from sleep problems [16]. Except for one study [30], music was applied for 30 min for 2 weeks in the other studies. The results of the studies showed mixed effects of music on pregnant women’s general stress. Two out of four studies reported that music reduced stress [16, 27], while the other two studies did not observe a significant difference in perceived stress between the intervention and control groups [28, 30].

The effect of music on pregnancy-related stress was examined in two studies [28, 33]. It was found that music intervention applied for 30 min daily for 2 weeks reduced pregnancy-related stress [28], while a single 30-min session of music intervention during transvaginal ultrasound did not show an effective reduction in pregnancy-related stress [33].

The effect of music-based interventions on anxiety was examined in eight studies included in the review [15‒17, 27, 29, 31‒33]. Only two RCTs examined the effect of music on anxiety in high-risk pregnant women [15, 31]. Music applied for 30 min during the nonstress test (NST) or transvaginal ultrasound was found to reduce anxiety in low-risk pregnant women [17, 33]. Other studies using music of different durations and frequencies found significant improvements in anxiety in low-risk pregnant women after the intervention [16, 27, 29, 32]. However, the effect of music on anxiety in high-risk pregnant women was unclear. One study reported that music used for 30 min daily for 3 days reduced anxiety in women hospitalized for more than 48 h for threatened preterm birth [31], while another study found no significant difference in anxiety between the experimental and control groups in women hospitalized for at least 5 days for a diagnosis of preeclampsia who received 5 days of the same duration of music intervention [15].

Only one study directly evaluated the impact of music-based interventions on depression. In the study, music was found to be effective in reducing symptoms of depression [27].

In addition, three studies evaluating the overall impact of music on maternal psychological health were included in this review [25, 26, 30]. In these studies, anxiety, depression, and stress were not evaluated directly but were assessed within the scope of quality of life, mental health, and psychological distress. One of the studies reviewed was of moderate quality and included high-risk pregnant women [26]. Two studies, including progressive muscle relaxation exercises accompanied by music and music-facilitated relaxation, found that music improved psychological parameters [25, 26]. However, another study that included composing a lullaby and listening to a recorded lullaby found no effect on psychological parameters [30].

Studies on the effect of music on maternal blood pressure and sleep quality in the prenatal period were evaluated. The effect of music on blood pressure was evaluated in hospitalized pregnant women with conditions such as threatened preterm birth, placenta previa, premature rupture of membranes [31], and preeclampsia [15]. The 30-min music intervention was applied at different frequencies in two studies [15, 31]. Music during the 5 days before birth did not lower blood pressure in hospitalized pregnant women with preeclampsia [15], while music used for 3 days was found to lower blood pressure in another study [31]. In addition to the effect of music on blood pressure, similar results were found for anxiety among psychological parameters. In the study reporting that music significantly reduced anxiety, blood pressure also decreased [31]. In the other study, however, music did not reduce either anxiety or blood pressure [15]. The effect of music on sleep quality was discussed in only one study, which found that music statistically significantly improved sleep quality in sleep-disturbed pregnant women [16].

In studies evaluating the effects of music on fetal parameters, different music intervention protocols were found. Music interventions were delivered applied as a single session during NSTs or in multiple sessions. Four studies examined the effect of music on baseline fetal heart rate. Of these studies, only one was of moderate quality [18], while the others were of low quality [15, 17, 31]. The study of moderate methodological quality used music intervention for both mother and fetus and found no statistically significant effect on baseline heart rate [18]. The other studies had conflicting findings on the effect of music on baseline heart rate [15, 17, 31]. The studies that examined the effect of music on fetal movement [15, 17] and the number of accelerations [17, 18] found some findings that music increased acceleration and fetal movement.

This systematic review of thirteen studies examining the effects of prenatal music interventions on maternal and fetal parameters was summarized. Our findings suggest that music-based interventions may benefit some maternal and fetal parameters in pregnant women. However, there is considerable heterogeneity in the study populations of the included studies, the characteristics of the music intervention, and timing of outcome assessment. The heterogeneity among the studies reviewed makes it difficult to assess the outcomes attributed to music, especially in terms of intervention protocols.

In this systematic review, the studies reviewed were of moderate to low methodological quality. Some limitations due to the nature of the music interventions (blinding) and the poor representation of the sample of studies in the population led to the assessment of the methodological quality of the studies as low. However, more precise descriptions of the music interventions, greater attention by researchers to protocols and guidelines during the study design process, and the use of methods and statistics to control for confounders may help produce study results of high methodological quality.

The results on the effectiveness of music in reducing stress are inconclusive. Some studies have suggested that music may reduce overall stress in low-risk pregnant women. However, these effects were not observed in other studies also involving low-risk pregnant women. Thus, within the reviewed studies, the effect of music on overall stress was indeterminate. Especially in cases where specific factors such as medical procedures trigger stress, it is essential to examine the effectiveness of music in more detail [33]. While music reduces anxiety in low-risk pregnancies, the results regarding the effect of music on anxiety in high-risk pregnancies are unclear. Considering that high-risk pregnant women experience more anxiety, examining the effectiveness of music in this group is crucial [34, 35]. Therefore, conducting studies with high methodological quality in this area remains an important research interest. Prenatal depression, on the other hand, can lead to complications related to pregnancy and childbirth and can affect fetal health and early childhood [36, 37]. Only one study evaluating the effect of music on depression was included in this systematic review, and it reported that music significantly reduced depression scores based on self-reporting questionnaires [27]. Considering the high prevalence of depression in pregnant women, there is a need to eliminate the numerical inadequacy of studies investigating the effectiveness of music in alleviating depression [38, 39].

There are limited studies that have investigated the impact of music on blood pressure, and the results of these studies are inconsistent [15, 31]. This may be attributed to the characteristics of the study population. One interpretation of the current findings is that music does not significantly reduce blood pressure in pregnant women with preeclampsia compared with the control groups. Additionally, the timing of outcome assessments for blood pressure and the study context (labor vs. nonlabor) differed between the two studies, which could have influenced the results. Therefore, the results should be interpreted with caution, and future studies should provide more detailed information on the assessment of physiological outcomes and consider the current context. These two studies also evaluated the effect of music on anxiety in high-risk pregnant women and produced similar results. These findings suggest that the effects of music on psychological and physiological parameters may be interrelated; however, further research is needed to confirm this. Only one study examined sleep quality and found that music improved sleep quality. However, additional empirical evidence is necessary to establish the effectiveness of music in pregnant women with sleep problems, as suggested by a previous meta-analysis of music interventions in adults with sleep difficulties [40].

It is believed that music may contribute to the mother’s emotional state and, in turn, have an effect on fetal parameters. This study supports the finding that music applied during NST reduces maternal anxiety and affects fetal cardiac activity [19, 41]. However, more research is needed to explain how listening to music outside of NST times affects fetal parameters.

The effectiveness of music varies depending on the type and tempo used. For therapeutic effects, a slow and meditative tempo (60–80 beats/min) that mimics the heartbeat is recommended [42]. In this review, all studies that reported on the tempo of music followed this recommendation. However, some studies have not reported the tempo of music [15, 18, 25, 26, 32]. The type and tempo of music are directly related to with the music selection. There is no clear consensus on whether music should be selected by researchers or participants. Although there is some evidence that music selection and music tempo do not affect stress-related outcomes in the general population [20, 43], it is still unclear in pregnant women [9]. From the studies in this review, allowing participants to select music from different categories appears to be a more frequently used method to evaluate the effects of music [15‒17, 26‒28, 31]. However, further well-reported studies addressing the effects of the characteristics of music interventions on outcome parameters in pregnant women are required.

This review has several limitations. First, most of the studies were rated as having low methodological quality and the studies were heterogeneous, especially with regard to the characteristics of the interventions. Therefore, the results of the trials must be interpreted with caution. In addition, most of the trials included low-risk pregnant women. The number of studies that included high-risk pregnant women was limited. Therefore, more studies are needed to assess the maternal and fetal effects of music, especially in high-risk pregnant women. There are weaknesses in the generalizability of this systematic review because it is difficult to establish clear links between the general health status of pregnant women and the effect of music. Therefore, further research is needed to provide more specific evidence, especially to reduce methodological heterogeneity.

Some findings suggest that music interventions could effectively improve maternal mental health during pregnancy and support maternal physiological health parameters and fetal well-being. Considering the potential benefits of music, as an easily applicable and cost-effective non-pharmacological intervention, further research is needed to clarify the effectiveness of music during pregnancy. In this review, the diversity of interventions across studies caused problems in comparisons, and having small groups with poor control caused the problem of genuinely assessing the effect. Therefore, additional, large-sample RCTs of high methodological quality are needed to obtain reliable clinical evidence on the maternal and fetal effects of music in pregnant women.

The authors would like to thank Gazi University Academic Writing Center for proofreading the article.

An ethics statement is not applicable because this study is based exclusively on published literature.

The authors have no conflicts of interest to declare.

There were no funding sources.

Aliye Dogan-Gangal: conceptualization, methodology, investigation, writing – original draft, and visualization. Belgin Akin: conceptualization, methodology, investigation, formal analysis, and writing – review and editing. Deniz Kocoglu-Tanyer: methodology, investigation, formal analysis, and writing – review and editing.

All data generated or analyzed during this study are included in this article. More questions can be directed to the corresponding author.