Physiological, psychological, social, or fetal factors may be detrimental to prenatal health, possibly leading to miscarriages, premature birth, or stillbirths (Hu, 2006; Dhillon et al., 2017). Thus, pregnant women may experience pregnancy stress; to reduce or eliminate such stress, they resort to using complementary medicine. Complementary medicine, such as religion, music, or acupuncture can reduce anxiety, unease, and uncertainty in tocolytic (a category of drugs used to delay the labor process) pregnant women and increase the therapeutic effectiveness of tocolysis (Tsai and Lee, 2012). Given these findings, complementary medicine and pregnancy stress are worthy to be investigated.

Complementary medicine has diverse types but is generally divided into five major categories: alternative medicine, natural products, mind and body medicine, energy therapy, and manipulative and body-based practices. Alternative medicines such as traditional Chinese medicine and naturopathy are slow-acting but can improve chronic diseases (Chiang, 2014; Pallivalappila et al., 2014; Mitchell, 2016). A 2008 survey involving obstetricians from the American Medical Association considered biofeedback, chiropractic care, acupuncture, and meditation as highly effective complementary medicine treatments (Babbar et al., 2017). Natural products emphasize that the human body itself has natural healing capabilities and that natural substances, such as natural herbs, high doses of vitamins, minerals, dietary fiber, probiotics, Lingzhi mushroom, shark cartilage, and cod liver oil, can be used to prevent diseases (Holst et al., 2009). In mind and body medicine, psychological stability can be improved using certain techniques, such as imagery, meditation, music therapy, yoga, prayer, biofeedback, journal therapy, art therapy, sitting still, humor, Tai Chi, and psychotherapy. Energy therapies, such as healing touch, therapeutic touch, Reiki, Qigong, and magnet therapy, refer to using energy from certain substances to stimulate the human body to achieve health. Last, manipulative and body-based practices are based on body manipulation and body movements, and these include chiropractic medicine, various massage techniques, body movements (e.g., osteopathy), rolfing, light therapy, hydrotherapy, and chromotherapy (Chen et al., 2010; Birdee et al., 2014; Guardino et al., 2014).

Currently, many pregnant women receiving tocolytic treatment use complementary medicine at suitable times to alleviate prenatal psychological stress and reduce stress, anxiety, labor pain, and depression, especially during labor. Hence, complementary medicine provides therapeutic effects during the entire pregnancy period (Deligiannidis and Freeman, 2014). Some types of complementary medicines are also specifically effective in mental disorders (Barcelona de Mendoza et al., 2016; Smith et al., 2019). However, pregnancy stress varies from individual to individual. The severity and type of stress experienced at the same pregnancy stage still varies because women differ in individual factors and life events. Stress occurs when pregnant women feel that they lose control or unable to cope (Yang and Chung, 2009). Rubin believes that maternal roles develop during pregnancy; one role is ensuring a healthy fetomaternal state until delivery (Rubin, 1976).

Frequently, pregnant women receiving tocolytic treatment possess factors that threaten maternal and fetal health, leading to difficulty in adapting to maternal roles (Rubin, 1976). This event causes pregnancy stress, which worsens if the pregnancy outcomes are uncertain; hence, pregnant women need more social support to adapt to pregnancy, particularly from their husbands and other family members. To alleviate such stress and uncertainty, using complementary medicine with pregnant women can be taught to use research-validated relaxation techniques, such as music, breathing techniques, and art therapy (Fang et al., 2011).

In Taiwan, most studies on complementary medicine treatment during pregnancy focused on the effectiveness of a certain type of complementary medicine, such as mind and body medicine (Mitchell, 2016). In addition, pregnancy stress in pregnant women receiving tocolytic treatment who use complementary medicine remains unreported. Therefore, this study aimed to compare pregnancy stress between pregnant women receiving tocolytic treatment and those who were receiving non-tocolytic treatment, where both used complementary medicine, to provide a reference for future studies by clinical staff.

The distribution of basic information between the pregnant women receiving tocolytic treatment and those who were receiving non-tocolytic treatment in this study was similar to that in a previous research involving pregnant women in Taiwan (Holst et al., 2009); most of the pregnant women aged 20–34 years, married, had a senior high school education or above, and primigravida. The present study then discussed and compared in the usage of complementary medicine and pregnancy stress between pregnant women receiving tocolytic treatment and those who were receiving non-tocolytic treatment. The findings can serve as future care guidelines and research directions. The insights into whether gestational age, preterm birth risk, and uncertainty can increase pregnancy stress should also be understood in detail. Pregnant women require sufficient time to rest, with a more accurate understanding of current complementary medicine usage during pregnancy through interviews, and environmental interference factors can be reduced.

This study analyzed the types of complementary medicine commonly used by pregnant women (Chiang, 2014; Pallivalappila et al., 2014; Mitchell, 2016) and found five major categories: alternative medicine, natural products, mind and body medicine, energy therapy, and manipulative and body-based practices. The complementary medicine types were reported between the groups of pregnant women receiving tocolytic treatment and those who were receiving non-tocolytic treatment. Both groups most frequently used natural products, the second most commonly used approach was alternative medicine in pregnant women receiving tocolytic treatment, and manipulative and body-based practices in those who were receiving non-tocolytic treatment. The study results clearly demonstrated those pregnancy characteristics among pregnant women, the choice and application of complementary medicine. As Sheraton et al. (2018) reported that women are increasingly using complementary and alternative therapies during pregnancy. This view is worthy of further investigation.

Regarding the use of alternative medicine during pregnancy, traditional Chinese medicine was most commonly used, followed by acupuncture, Chinese herbal medicine, and Tuina, similar to a study in New Zealand (Zheng et al., 2018). Both groups mostly used vitamins, probiotics, and cod liver oil as natural products, similar to previous studies (Johnson et al., 2016; Gilmartin et al., 2018; Zheng et al., 2018). Moreover, yoga and hypnosis were mainly used as mind and body medicine, consistent with previous studies (Chen et al., 2013; Gavin et al., 2020). In this study, pregnant women receiving tocolytic treatment did not use energy therapy, and no literature study has reported the use of energy therapy during pregnancy. In pregnant women who were receiving non-tocolytic treatment, massage was mostly used as a manipulative and body-based practice, similar to previous studies (Hung and Chiang, 2017; Fogarty et al., 2019).

The Pregnancy Stress Rating Scale score, dimension 2 (stress caused by infant care and changes in family relationships), and dimension 5 (stress caused by changes in physical appearance and function) were significantly different between the two patient groups. Although both groups used complementary medicine, the pregnant women receiving tocolytic treatment showed less pregnancy stress than those who were receiving non-tocolytic treatment. Dimension 2, which focuses on stress caused by infant care and changes in family relationships, was significantly lower in pregnant women receiving tocolytic treatment than those who were receiving non-tocolytic treatment. Family relationship changes require important family support to achieve the entire process of adaptation. Therefore, the acceptance of others during pregnancy is very important to the psychology of pregnancy, such as pregnant women receiving tocolytic treatment who just focus on a fetus, hope to ensure the safety of themselves and their fetus (Chen, 2015; Chang et al., 2016).

Dimension 5, which refers to stress caused by changes in physical appearance and function, showed the same finding. The pregnancy stress can be caused by changes in body appearance and function becomes more obvious as the pressure increases during pregnancy (Chen, 2015). Therefore, we hypothesized that as the gestational age advances in pregnant women, their physical appearance changes more significantly. This view is consistent with a previous study (Chang et al., 2016), which reported that stress caused by changes in physical appearance and function appears in early pregnancy and gradually peaks at late pregnancy.

However, the Pregnancy Stress Rating Scale scores for dimension 1 (stress caused by ensuring mother and child health and safety), dimension 3 (stress caused by acknowledging maternal role), and dimension 4 (stress caused by seeking social support) were not significantly different between the two groups. These dimensions are critical for both pregnant women receiving tocolytic and those who were receiving non-tocolytic treatment, consistent with Rubin’s view that maternal tasks develop during pregnancy. Examples for such tasks include ensuring that the mother and fetus can successfully undergo pregnancy and delivery and adapt to maternal roles (Rubin, 1976). This result is consistent with a previous study (Fang et al., 2011). Thus, pregnant women require more social support to adapt to pregnancy. Generally, pregnant women receiving tocolytic treatment have factors that are detrimental to maternal and fetal health, resulting in difficulty in overcoming pregnancy-related stress.

Mental health should be considered during pregnancy (Gong et al., 2020; Martínez-Borba et al., 2020; Rodríguez-Muñoz et al., 2020). The present study revealed pregnancy stress. However, convenience sampling limits the generalizability of the findings. We collected data from only one medical center in central Taiwan. Therefore, generalizing the results to other pregnant women receiving tocolytic and those who were receiving non-tocolytic treatment should be undertaken with caution.

This study provides the following recommendations for future research directions, education, and clinical practice. First, regarding future research, healthcare professionals should thoroughly examine community homes to explore the correlation between pregnant women receiving tocolytic treatment who use complementary medicine and their pregnancy stress. They must ensure that they understand the types of complementary medicine and their effects in such people. Regarding educational recommendations, healthcare professionals should develop knowledge and skills related to complementary medicine to improve their care ability for pregnant women receiving tocolytic treatment. In clinical settings, they can explore and understand how to provide comprehensive care for pregnant women receiving tocolytic treatment and to know the pregnancy stress of pregnant women.

In conclusion, although both pregnant women receiving tocolytic treatment and those who were receiving non-tocolytic treatment used complementary medicine, pregnancy stress was significantly lower in the former than in the latter. This finding can be used as a reference for future studies on pregnant women’s health. All findings in this study support the use of complementary medicine at suitable times if pregnant women agree that complementary medicine is beneficial during pregnancy.