The postpartum returning nurses should be a key concern group for nursing managers. The increased stress of returning to work after maternity leave will lead to serious tension and difficulty in concentration, which will seriously affect their physical and mental health , and also lead to postpartum returning nurses becoming a potential high-risk group for clinical nursing errors and accidents, which will reduce the quality of nursing care . In previous studies, the research tools used to investigate the stress of postpartum returning nurses have been generic work stress scales. This study is the first to use a specific work stress assessment tool for postpartum returning nurses. The results show that the dimension with the highest score in this study was “maternal role commitment.” This contrasts with previous research, in China and other countries, in which “nursing profession and work,” has been identified as the most significant stressor for clinical nurses [24, 25]. The main stressors were “breastfeeding time cannot be guaranteed after returning to work” and “lack of physical strength and energy due to childcare after returning to work.”
There are several reasons for this difference. Firstly, although nurses can temporarily leave children in the care of grandparents when they are working, according to Chinese tradition women need to take more care of their families. According to the surveys, in China, mothers are the primary caregivers of infants and toddlers aged 0–3 years , and the percentage of children who are primarily cared for by their mothers at night is as high as 74.1% . Therefore, the vast majority of postpartum returning nurses still need to care for their children after work. This leads to nurses’ need to combine more maternal roles and tasks with their return to work and to invest more time and energy in raising their children.
Secondly, the nurses with two children are faced with a greater problem of physical recovery because of age-related decline in their bodies or to the effects of birth and childcare . The duration of maternity leave in China is 98 days, but each province has its own regulations. Most maternity leave is 98 to 158 days, and very few will be extended to 1 year. But in practice, some nurses are not entitled to full maternity leave due to the shortage of nurses in the department and the need to work . As a result, many nurses not recovered to the physical demands of being able to stand for long periods of time and perform intense nursing work, and at the same time, they need to face the contradiction between taking care of their children and their own lack of physical strength and energy .
Finally, participants’ return to work coincides with their period of breastfeeding. The World Health Organization (WHO) recommends that babies be exclusively breastfed for the first 6 months and that breastfeeding should then continue for 2 years or more . Chen’s  research points out that nurses’ period of breastfeeding in China is far from meeting the WHO recommendations, and is often actively interrupted by physical fatigue, increased work stress, and a lack of support in their departments. Although nurses have returned to work, as breastfeeding mothers they still need to express milk regularly during working hours. However, due to the continuity of nursing work, many departments cannot guarantee them the necessary time for this. In addition, in China there are also some deficiencies in the provision of suitable spaces in which nurses can express milk. In a survey of four tertiary A hospitals in Shandong Province, 64.25% of the departments did not have clean and private space in which women could express their milk, and 46.93% of the departments did not provide refrigerators, freezers, and other milk storage facilities . These deficiencies increased nurses’ worries about breastfeeding after returning to work, further increasing their stress.
The relationship between returning nurses’ stress and their level of family income
In 2020, the annual per capita disposable income of urban residents in China was 43,834 yuan, and the per capita consumption expenditure was 27,007 yuan. Although the income level of nurses in China is higher than the national average, it is not a highly-paid occupation. In particular, second-child nurses face the double stress of the material and parenting of two children, which increases the economic burden on the family . In this study, 38.17% of nurses had a monthly income of less than 10,000 yuan, and the lower the family income, the higher their work stress. Cohen’s  research also confirms this. Many developed countries have relatively good maternity insurance systems, the welfare benefits given by their governments to nurses who are mothers are relatively generous, and various subsidies are provided for families to reduce their financial burden [35, 36]. Although China has formulated corresponding regulations on the protection of maternity leave, so that nurses can enjoy maternity leave allowance, maternity medical allowance and other benefits in accordance with the law, compared with developed countries there is still a big gap . This increases the work stress of postpartum nurses from low-income families. China also needs to further improve the social welfare system to ensure that nurses are given appropriate incentives and benefits according to the actual situation of their local hospitals, while enjoying the maternity leave stipulated by the national policy. This would reduce the family burden on lower income groups.
Nurses with younger first child have higher work stress
Shu’s  research points out that nurses returning to work following the birth of a second child need more time to take care of their older children’s needs and education, in addition to caring for their second child. This further adds to the demands made by their work. The results of this study show that the work stress of nurses with lower age of the first child was higher than child with older age. This may be because younger children, in the early childhood and preschool stage, are more active and curious, factors which contribute to this age group showing the highest incidence of accidental injuries . At the same time, this is also an important period for children’s intellectual and social development. The formation of lifelong habits is completed at this stage [39, 40]. After a second birth, nurses have to face the heavy work and upbringing of two children and the time spent on the care of the first child is inevitably reduced. Therefore, managers should fully understand the family situation of second-child nurses, arrange shifts reasonably to help them better alleviate the conflict between work and family, and the nurses should encourage their husbands to actively assume family responsibilities and shoulder the task of taking care of their eldest children. This would help to create a good family atmosphere.
The relationship between work stress in postpartum returning nurses and the passage of time
The results of this study show that participants’ levels of post-return work stress change over time, being higher in the first 3 months, especially in the first month, and show a downward trend with the extension of return time. This is similar to the results of studies on work stress and adaptation of postpartum returning nurses by Lin  and Chen . This trend may be related to the fact that in such a short time after returning to their post, nurses with a second child find it difficult to adapt the high-intensity work rhythm, or master the changes in technology and knowledge that have occurred in their absence. However, with the passage of time, they can gradually become familiar with the necessary knowledge and skills, so as to reduce their level of work stress. Some researchers have pointed out that nurses with a second child have a low level of adaptation to work within 3 months after returning  and show a greater lack of self-confidence in completing their work, causing serious mental stress . Therefore, it is suggested that nursing managers should pay special attention to the return of second-child nurses during the first 3 months after maternity leave. They should actively help these nurses to formulate a suitable post-return training plan and establish good family support relationships. Managers should dynamically adjust the nurses’ work according to their actual situation and according to the principle of gradual and orderly progress, so as to shorten the maladjustment period of returning to work and gradually reduce the nurses’ work stress.
The relationship between depressive symptoms and work stress in postpartum returning nurses
Postpartum hormone changes in the body make women more prone to depression, anxiety, and other negative emotions. Kamau’s  research shows that postpartum depressive symptoms can seriously affect postpartum work status and weaken women’s ability to return to normal work. This study found that 60.71% of the participants who returned to work after giving birth had depressive symptoms, and the higher the level of depressive symptoms, the greater their work stress. A previous study  has found that depression scores are positively correlated with all dimensions of work stress scores. When nurses’ depressive symptoms cannot be addressed effectively, it will increase their work stress. Lin  has shown that nurses’ work stress is positively correlated with their level of depressive symptoms, and high work stress can also lead to severe depressive symptoms. Therefore, for pregnant nurses it is necessary to screen their state of prenatal and postpartum depressive symptoms, and to provide suitable support measures in advance, for example, by increasing mental health services and enhancing mental support. For postpartum nurses with a tendency towards depression, nursing managers can appropriately extend their maternity leave. In the absence of a long maternity leave, nursing managers should be aware of the possibility of postpartum depressive symptoms and provide appropriate support for postpartum returning nurses.
The relationship between work stress and turnover intention in postpartum returning nurses
In this study, 27.23% of nurses returned to work after giving birth to their second child, which is lower than the level of turnover intention found by Yang et al  in nurses across China. Studies  have shown that difficulties in balancing work and family roles lead to higher turnover intentions. Nurses returning to work after having a second child are faced with the heavy workload involved in caring for their family and children at the same time, and the conflict experienced between family and work commitments is serious. However, raising a family is expensive, many nurses cannot bear the economic losses caused by leaving their work. Even if they wanted to leave, they could not do so easily. Lai’s  research also confirms this. Therefore, many nurses who return to work after delivery want to leave, but have to continue to work, which undoubtedly increases their work stress. Managers should pay attention to the turnover intention of postpartum returning nurses, and take a scientific and human approach to their management that meets their life and psychological needs. Nurses themselves should actively try to maintain good mental health and strengthen their ability to adjust to their new circumstances.
This study gives the researcher food for thought in terms of gender inequality. Looking at the global health industry, women typically receive fewer opportunities for advancement and lower salaries than men, and the impact of gender differences adds to the work stress of female health care workers [50, 51]. Women face the same competition as men in the labor market and are required to meet the same work standards as men, but in the home, women take on more responsibility for caring for their families. Therefore, managers at all levels should pay attention to the realization and protection of women’s rights and interests, promote the trend toward equal social resources owned by both genders, change gender equality within the family, and help nurses returning to work after childbirth to share the task of child care in order to help them reduce stress.