Evaluating the impact of an educational self-care intervention on the empowerment of primigravida pregnant women covered by family medicine program in the Estahban City —an application of the Pender’s health promotion model
In every woman’s life, several phases affect her life, one of which is pregnancy . The transition to motherhood is accompanied by many different physiological, psychological, social and biomechanical changes , which make this a stressful period and have irreparable physical and psychological effects on the fetus and the mother . The results of the latest estimate of World Health Organization statistics show that the number of maternal deaths increased by 34% worldwide between 2000 and 2020. In 2020, almost 800 women worldwide died every day from preventable causes related to pregnancy and childbirth, most of which were due to health care provided by skilled health personnel before, during and after childbirth. The Sustainable Development Goal 3.1 is to reduce maternal mortality to less than 70 per 100,000 live births by 2030 ( https://www.who.int/publications-detail-redirect/9789240068759 ). Behavior change can be influenced by various factors, such as knowledge . Health information can be obtained from a variety of sources . In the online era, although the internet is the most convenient source of information, information from nonprofessional sources confuses participants and cannot be compared with the accuracy of medical knowledge . Therefore, formal sources such as health care are the most widely used . Although the content and adequacy of prenatal care are related to the outcome of a healthy pregnancy, they are not sufficient for an optimal pregnancy outcome. In recent years, the concept of self-care has been proposed in the philosophy of primary health care . Self-care is particularly important for vulnerable populations, which include pregnant women, as they do not have easy access to the health care system. People choose self-care for many positive reasons, including convenience, cost, personal responsibility, and recognition by the healthcare system . Self-care during pregnancy refers to the choices and activities a pregnant woman undertakes to manage problems and issues related to her health during this time to improve the health of herself and her fetus . According to the World Health Organization and the International Conference on Population and Development, women play a fundamental role in the empowerment and health of their families . This is because they can facilitate positive physical and psychological outcomes for themselves, their children and their families  and improve reproductive health . According to the World Health Organization’s definition, empowerment is a process by which people have more control over their choices, lifestyle and activities, which has an impact on their health . Therefore, it seems necessary to empower pregnant women to adapt to these changes. Empower during pregnancy is defined as a feeling of self-efficacy, satisfaction, increased independence and improved interaction with others and the surrounding environment, which leads to a successful pregnancy and delivery . Currently, education is accepted as a part of the activities of all healthcare system employees . If women are trained, they develop their inner strength and improve their independence and ability; they can overcome the adversities and changes of pregnancy and experience better physical and mental performance with the improvement of ability; and finally, they will have a successful pregnancy and delivery, which is the dream of every mother . Despite the importance of self-care for pregnant women, no comprehensive research has yet been conducted to clarify the concept of self-care . On the other hand, there are many theories and models in the field of health promotion . Choosing the right theory or model in health planning leads to the recognition of key factors and the determination of the right path of educational intervention. Pender’s health promotion model seems to provide a comprehensive model for predicting health-promoting behaviors, which focuses on individual experiences and characteristics, emotions, behavior-specific cognitions, and behavioral outcomes. Additionally, social, individual and demographic factors have been seen more fully in this model, and in this model, in addition to prevention, Pender has paid more attention to health promotion, whereas in other models, such as the health beliefs model, only the aspect of prevention of health-related issues has been raised. Therefore, a program based on the Pender Health Promotion Model for self-care capability for pregnant women was not found; therefore, this study was conducted with the aim of “Evaluating the effect of self-care educational intervention on the empowerment of primigravida pregnant women covered by the Family Doctor Program of Estahban city”. 

The present study was a randomized controlled trial that was conducted to evaluate the effect of self-care educational intervention on the empowerment of pregnant women in Estahban city, with the participation of 80 primigravida pregnant women referred to centers covered by the Family Doctor Program to receive health services. The required sample size was calculated on the basis of the results of similar studies, with the help of PASS version 15.0.5, with a mean of 4.07, standard deviation of 0.58, confidence level of 95% and an error of 5%, 64 people were obtained; with a drop of 15%, 76 people were calculated, and 80 people (40 people in each group) were finally included in the research sample [ , , ]. After receiving the code of ethics and obtaining a license, sampling was performed with the cooperation of health workers. For the generalizability of this study’s results and the maximum reduction in socioeconomic differences, the samples of two control and intervention groups from 4 established comprehensive health centers, completely randomly, 2 centers together with covered centers as the control group and two health centers with their covered centers, were selected as the intervention group. In the selected centers, from the SIB system, the names of the qualified women with the inclusion criteria of being interested in participating in this study, having at least reading and writing literacy (primary), having listening and speaking abilities, being Iranian and not having any known physical or mental illness that caused the nonparticipation of pregnant women in this study, were not selected from the high-risk group, not participating in birth preparation classes, being primigravida and having a gestational age of 14–28 weeks. Among the qualified women to enter this study, 40 people were randomly selected as the control group, and 40 people were considered the intervention group. Then, during a meeting, they were invited, and while explaining how the project was carried out, the confidentiality of the information and the purpose of this study, they were asked to provide their demographic information, Kameda’s empowerment of pregnant women and the Researcher-Designed Questionnaire “Self-care Ability in Pregnancy (SSAP)”. In the next stage, 6 sessions of 90 min were organized for the intervention group, with one session per week. One month after the educational intervention, the questionnaires were completed again. The data collected after coding were analyzed via SPSS version 27 and statistical methods such as chi-square tests, independent t-tests and paired t-tests (Fig. ). Information collection tool The first part of the questionnaire included demographic information, the second part included questions from the Kameda questionnaire on the empowerment of pregnant women, and the third part included questions from the Pender model questionnaire designed by the researcher. The content of the demographic questionnaire included education, age, occupation, number of births, income, type of pregnancy (intended or unintended), and gestational age. The Kameda Pregnant Women’s Empowerment Questionnaire includes 27 questions in 5 dimensions, including self-efficacy with 6 questions, future image with 6 questions, self-esteem with 7 questions, support and reassurance from others with 4 questions, and joy of adding a family with 4 questions. These items were answered on a Likert scale from “strongly disagree” to “strongly agree” with scores ranging from 1 to 5 (strongly disagree, disagree, have no opinion, agree, strongly agree). A minimum score of 27 and a maximum score of 108 were awarded for the answers. The Persian questionnaire was used in this study, and its validity and reliability were confirmed with a Cronbach’s alpha of 0.89 by Leila Hajipour and colleagues . The researcher’s questionnaire was created on the basis of the Pender model through holding a meeting with the elite panel. A series of items were proposed by the group; after group consultation, 58 questions with 5 items and a 5-point Likert scale were proposed. The face and content validity of the questionnaire was checked and confirmed through a panel of experts and by surveying health education experts and calculating the CVI and CVR and internal reliability by calculating Cronbach’s alpha and external reliability via the retest method on a pilot sample of 30 people. In terms of content validity, 17 questions were removed from the initial questionnaire because the CVI was below 79% and the CVR was below 62%, and 4 questions were added to the initial questionnaire (45-question questionnaire or SSAP-45 items). As a result of face validity, several questions became clearer, simpler and more complete. In the second step, the questionnaire was evaluated in terms of the necessity component and the relationship of the tool with the scope of measurement. In the third step, the tool was validated. After checking, it seemed that Cronbach’s and MacDonald’s alphas would improve if 5 more questions were removed (SSAP-40 items questionnaire). Additionally, construct validity was calculated with the help of Pearson’s correlation coefficient between questions, subscales and the total score of the questionnaire, which shows a correlation greater than 0.4 (0.754) and shows that the constructs of this tool are also valid. As a result of the factor analysis, it appeared that the questionnaire could be deleted and edited up to the 26% level ( p = 0.002). According to the proposal of the fit distribution of the Polytomous Rasch model for the SSAP-40 item questionnaire and the infit and outfit indicators, 2 more questions were also removed (SSAP-38 items). Therefore, the final questionnaire had 38 questions . This questionnaire was prepared for this study and has not been used in any other study so far. How to intervene After receiving the code of ethics (IR.SUMS.SCHEANUT.REC.1402.117) and also registering in the clinical trial portal with the trial code 73,547 and IRCT20131014015015N23 was completed before starting the work and after obtaining the necessary permits, the questionnaires and the ethical consent form were approved by all the participants of both groups in compliance with ethical principles. The educational intervention for the intervention group consisted of 6, 90-min educational sessions. The meetings were held over 1.5 months and every week with group discussions, questions and answers, PowerPoints and brochures. The contents of the educational intervention included statements of program goals, increased familiarity with pregnancy, familiarity with the empowerment approach and its dimensions, the importance and necessity of self-care during pregnancy, common problems during pregnancy and solutions to address them. How to complete the questionnaire was explained to pregnant women, and the questionnaires were completed before and 1 month after the educational intervention by the intervention and control groups. After completing the research process, the control group received the educational intervention in the form of an explanation of a complete and comprehensive educational booklet. Data analysis The data were analyzed via SPSS version 27 at a significance level of 0.05. Demographic variables were compared between the two groups via the chi-square test. Pender’s health promotion model constructs and empowerment subscales were compared between the two groups via independent t- tests. Additionally, the mean scores of the variables of each group in this study were compared via paired t-tests before and after the intervention. 

The first part of the questionnaire included demographic information, the second part included questions from the Kameda questionnaire on the empowerment of pregnant women, and the third part included questions from the Pender model questionnaire designed by the researcher. The content of the demographic questionnaire included education, age, occupation, number of births, income, type of pregnancy (intended or unintended), and gestational age. The Kameda Pregnant Women’s Empowerment Questionnaire includes 27 questions in 5 dimensions, including self-efficacy with 6 questions, future image with 6 questions, self-esteem with 7 questions, support and reassurance from others with 4 questions, and joy of adding a family with 4 questions. These items were answered on a Likert scale from “strongly disagree” to “strongly agree” with scores ranging from 1 to 5 (strongly disagree, disagree, have no opinion, agree, strongly agree). A minimum score of 27 and a maximum score of 108 were awarded for the answers. The Persian questionnaire was used in this study, and its validity and reliability were confirmed with a Cronbach’s alpha of 0.89 by Leila Hajipour and colleagues . The researcher’s questionnaire was created on the basis of the Pender model through holding a meeting with the elite panel. A series of items were proposed by the group; after group consultation, 58 questions with 5 items and a 5-point Likert scale were proposed. The face and content validity of the questionnaire was checked and confirmed through a panel of experts and by surveying health education experts and calculating the CVI and CVR and internal reliability by calculating Cronbach’s alpha and external reliability via the retest method on a pilot sample of 30 people. In terms of content validity, 17 questions were removed from the initial questionnaire because the CVI was below 79% and the CVR was below 62%, and 4 questions were added to the initial questionnaire (45-question questionnaire or SSAP-45 items). As a result of face validity, several questions became clearer, simpler and more complete. In the second step, the questionnaire was evaluated in terms of the necessity component and the relationship of the tool with the scope of measurement. In the third step, the tool was validated. After checking, it seemed that Cronbach’s and MacDonald’s alphas would improve if 5 more questions were removed (SSAP-40 items questionnaire). Additionally, construct validity was calculated with the help of Pearson’s correlation coefficient between questions, subscales and the total score of the questionnaire, which shows a correlation greater than 0.4 (0.754) and shows that the constructs of this tool are also valid. As a result of the factor analysis, it appeared that the questionnaire could be deleted and edited up to the 26% level ( p = 0.002). According to the proposal of the fit distribution of the Polytomous Rasch model for the SSAP-40 item questionnaire and the infit and outfit indicators, 2 more questions were also removed (SSAP-38 items). Therefore, the final questionnaire had 38 questions . This questionnaire was prepared for this study and has not been used in any other study so far. 

After receiving the code of ethics (IR.SUMS.SCHEANUT.REC.1402.117) and also registering in the clinical trial portal with the trial code 73,547 and IRCT20131014015015N23 was completed before starting the work and after obtaining the necessary permits, the questionnaires and the ethical consent form were approved by all the participants of both groups in compliance with ethical principles. The educational intervention for the intervention group consisted of 6, 90-min educational sessions. The meetings were held over 1.5 months and every week with group discussions, questions and answers, PowerPoints and brochures. The contents of the educational intervention included statements of program goals, increased familiarity with pregnancy, familiarity with the empowerment approach and its dimensions, the importance and necessity of self-care during pregnancy, common problems during pregnancy and solutions to address them. How to complete the questionnaire was explained to pregnant women, and the questionnaires were completed before and 1 month after the educational intervention by the intervention and control groups. After completing the research process, the control group received the educational intervention in the form of an explanation of a complete and comprehensive educational booklet. 

The data were analyzed via SPSS version 27 at a significance level of 0.05. Demographic variables were compared between the two groups via the chi-square test. Pender’s health promotion model constructs and empowerment subscales were compared between the two groups via independent t- tests. Additionally, the mean scores of the variables of each group in this study were compared via paired t-tests before and after the intervention. 

The present study was conducted to evaluate the effect of a self-care educational intervention on the empowerment of primigravida pregnant women covered by the Family Doctor program on the basis of the Pender health promotion model in Estahban City. According to the arrangements, the number of samples that fell was 0. Table shows the frequency distribution of demographic information in the intervention and control groups. The participants in this study were 80 pregnant women. The mean age of the participants in the intervention group was 30.62 ± 6.36 years, and that in the control group was 30.77 ± 5.44 years. The results of the independent t- test revealed that the intervention and control groups were not significantly different in terms of mean age. Additionally, the results of the chi-square test revealed that there was no significant difference between the two intervention groups and the control group in terms of education, occupation, economic status, abortion experience or type of pregnancy (Table ). The results show that before the intervention, there was no significant difference between the intervention group and the control group in the mean values of the Pender’s health promotion model constructs (independent t- test). However, 1 month after the intervention, there was a significant difference between the two groups in terms of the mean score of all the constructs ( p < 0.001). The paired t- test revealed that, in the intervention group, the mean scores of perceived benefits, perceived barriers, commitment to an action plan and behavior after the intervention were significantly different from those before the intervention ( p < 0.001). Notably, although the mean scores of interpersonal effects in this test did not significantly differ, they did show an increase in mean scores postintervention compared with preintervention. In addition, this test revealed that, in the control group, the mean values of the structures before and after the intervention did not significantly change (Table ). The results showed that, on the basis of the independent t- test, before the intervention, there was no significant difference in the mean scores of the empowerment subscales between the intervention and control groups. However, 1 month after the intervention, there was a significant difference between the two groups in terms of the mean score of all the subscales ( p < 0.001). Paired t-tests revealed that, in the intervention group, the mean scores of self-efficacy and self-esteem after the intervention were significantly different from those before the intervention ( p < 0.001). However, the mean scores of future image, social support and joy of an addition to the family did not significantly differ in this test; however, we observed an increase in the mean scores after the intervention compared with before the intervention. Additionally, this test indicated that in the control group, the mean scores of all the subscales before and after the intervention did not significantly change (Table ). 

This study was conducted with the aim of improving self-care skills among pregnant women in the city of Estahban. The lack of differences between the studied groups in terms of demographic variables shows that this study includes steps that are carried out with high precision and properly. Fertility empowerment and increasing people’s ability to achieve their fertility goals are known to be the most important components of self-care . In the present study, the constructs of the Pender’s health promotion model and empowerment subscales were in a more favorable state in the intervention group after the educational intervention than in the control group. Similar studies have shown that self-care during pregnancy can be effective in reducing unfavorable pregnancy outcomes and improving pregnancy and birth outcomes, which can be achieved through educational interventions . The significant difference between the two intervention groups and the control group after the educational intervention may be good evidence of the effect of the educational intervention on the perceived benefits of pregnant women’s self-care practices and the direct relationship between the perceived benefits and self-care practices in the intervention group. The results of this study show that pregnancy planning, which depends on the type of pregnancy (intended or unintended), is one of the factors influencing self-care aimed at providing regular prenatal care. During these consultations, pregnant women receive information about vaccinations, underlying diseases related to pregnancy, pregnancy risk factors, personal hygiene, diet and nutrition, activity and exercise, the importance of adequate sleep and rest and ways to maintain mental and emotional peace in times of stress and anxiety. Effective communication between health care providers, doctors and pregnant women was also one of the points that led to a reduction in mothers’ anxiety and an increase in self-care behaviors. For example, according to several participants, midwives used to remind them of the time of care, which promoted the responsibility of pregnant women. Some mothers said that the knowledge and calmness of the doctor and health care provider makes them calm and full of energy. For example, according to their statements, some doctors scare people and stress them, which makes pregnant women anxious. The findings of Vasegh Rahi Rahim Parvar et al. in 2021 are consistent with those of this study . Research has shown significant differences in the scores of perceived barriers between the intervention group and the control group. On the basis of these findings, impatience and fatigue during pregnancy and a lack of family support in performing housework were presented as barriers in this study. This finding is consistent with Bashirian et al.’s research in 2023 . According to this study, several reasons for not providing self-care were proposed; for example, they did not receive relevant information from health professionals or received less information in general. In general, insufficient information and low awareness regarding self-care and its importance were summarized as the main barriers in the findings of the interviews, which may be due to the lack of reliable evidence about participation in self-care training and the relationship between participation and pregnancy outcomes. It also sometimes happens, that they do not understand the meaning or do not trust the correctness and accuracy of self-care. These findings are in line with the findings of the study by Giacco et al. in 2020 . Unknown terms used during counseling and low levels of education were also other barriers to accepting the principle of self-care. The results of the present research are consistent with the results of previous studies . Another barrier to self-care for pregnant women is economic barriers. In terms of the number of participants, many pregnant women cannot even perform a series of tests and care due to economic problems. Some described accessing appropriate care issues on the basis of their public insurance. Some stated that they were not aware of the type of insurance accepted by the clinic, which caused them to pay high fees without insurance. Others expressed frustration with calling multiple clinics to determine whether their insurance would be accepted or not, or which facility would accept which insurance for what type of care. Additionally, many mothers felt that they had access to fewer providers and services than women with private insurance. These results are in line with the results of previous studies . The lack of a specific plan for self-care and adequate training and educational resources, such as self-care educational materials and adequate facilities and services from health centers for pregnant women, are among the barriers related to the health system and the health team; the results of the study by Rahim Parvar et al. in 2021 confirmed this importance . A lack of privacy during prenatal visits to health services at health centers is a serious barrier to health information exchange between clients and health care providers and affects pregnant women’s trust in providers, which is in line with the findings of a comparative study by colleagues in 2020 . Poor counseling by health care professionals about the importance of regular medical visits, followed by delays and irregular access to health care services, were other major barriers to self-care. Another major obstacle in self-care is the adoption of healthy eating habits. The desire for certain foods, along with their lack of affordability, is among the serious challenges that make it difficult to adjust the diet for pregnant women with low socioeconomic status, which is consistent with the results of previous studies . Another major barrier to self-efficacy and self-care is the inability to adopt healthy eating habits. The desire for special foods along with its lack of affordability are among the serious challenges that make it difficult for pregnant women with low economic status to adjust their diet. According to a number of participants, there are many pregnant mothers who cannot even afford a series of tests and care due to economic problems. Some also described issues related to access to appropriate care based on their public insurance. One of the main barriers to accessing information from healthcare providers was feeling embarrassed or ashamed about talking about pregnancy-related issues and asking pertinent questions. The 2020 study by Verdzotto et al. confirms these findings . In line with the results of the study by Ghiasi et al. from 2021, unpredictably long waiting times at the clinic and lack of time due to household responsibilities were also cited as further barriers . In line with the findings of studies conducted with working pregnant women, some barriers included paid or unpaid maternity leave and flexible working hours. The working participants were annoyed by the lack of cooperation from their colleagues and officials in taking hourly and daily leave due to the physical limitations caused by pregnancy. In the current situation where women constitute a significant percentage of the workforce, proper policies and laws regarding the employment of pregnant women are necessary . Although pregnancy-related health information is free at health centers, the long distance to the centers and transportation problems are serious barriers that result in the inability or unwillingness of some participants to use the available service . Some reported that poor road access and a lack of public transport made it difficult to attend self-care educational interventions and subsequently practice self-care . The stronger role of the wife in making decisions even about pregnancy issues was one of the other barriers, such that women with greater independence in household decision-making were more likely to participate in these educational interventions and consequently had better self-care performance . Several participants commented on their husbands’ thoughts and performances, which were influenced by traditional gender structures in their native communities, and what often deterred them from using antenatal care services was their husbands’ decision and permission . Some of them complained about their husband’s misbehavior, which was rooted mainly in their different cultural backgrounds and led to a decrease in self-care performance . One of the most important barriers to self-efficacy is feeling ashamed or embarrassed to talk about pregnancy-related issues and asking related questions, which is influenced by socio-cultural contexts. Also, some of them complained about their spouses’ misbehavior, which is mainly rooted in their different cultural backgrounds and has led to a decrease in self-efficacy and thus self-care. Like the results of the studies, the type of pregnancy (intended or unintended) was also an effective factor. In unintended pregnancies, the probability of missing prenatal care during the first trimester is high. According to the results of this study, the capacity of the clinic was considered limited, so having more providers in a clinic can probably be helpful . A common reason for nonparticipation for several participants was fear of disclosing the pregnancy and being judged by others. A negative perception of healthcare professionals and an unpleasant experience also influence health-seeking behavior . Poor communication between doctors, midwives and pregnant women  and ineffective communication during antenatal visits are other barriers . On the other hand, some pregnant mothers said that they enjoyed interacting with other experienced mothers and felt constantly supported . Furthermore, the results of the present study revealed a significant difference in the mean values of the interpersonal effects before the intervention compared with those after the intervention in the intervention group. People with strong intentions can act faster than people with weak intentions . Consistent with the results of previous studies, excellent personal qualities such as independence, courage and flexibility, as well as a logical and calm attitude toward life, played a positive role in promoting self-care. However, most of the participants reported that although they were aware of the importance of self-care, participated in the training and had some prerequisites, they still found it difficult to continue due to their laziness . One group of mothers reported that their unpleasant feelings, such as sadness, anger, anxiety, fear, disgust and loneliness, personal interests/hobbies, workload and responsibilities, influenced their lifestyle and thus their self-care during pregnancy. These findings are consistent with the results of previous studies . The mean scores of the empowerment and its subscales (self-efficacy, future image, self-esteem, perceived social support, and happiness about the addition to the family) in the present study showed that mothers had lower empowerment before the intervention, whereas after the intervention, the mean scores of the empowerment and its subscales increased significantly. These results are consistent with those of related studies. The construct of self-efficacy is an important predictor of behavior change . A sense of self-efficacy is an important and effective prerequisite for successful self-care behavior . This study revealed a negative relationship between self-efficacy and maternal stress . The results also revealed that people with high self-efficacy demonstrate a greater desire to engage in challenging behaviors, interpret health and hygiene behaviors better, and can easily control their behaviors. Additionally, self-efficacy plays an important role in adjusting the relationship between people’s knowledge and behavior . In one study, Badaghi et al. mentioned social support as an important protective factor against depression and anxiety in pregnant women . In addition, higher levels of self-care improve family relationships and self-esteem, self-confidence and maternal worth. The 2021 study by Samira Khayat et al. confirms this finding . The conducted research showed that although many researches have been conducted regarding pregnant women, no research has been conducted so far in order to improve self-care ability in primigravida pregnant women of Estahban city. Also, according to the searches that took place in the databases and reliable scientific sites, a program based on the Pender health promotion model for self-care capability in pregnant women was not found; Also, in the present study, the common problems during pregnancy and the solutions to deal with them were comprehensively taught in the form of self-care activities in educational sessions, while other studies only examined some of these things, such as dietary changes and physical activity. In addition, identifying barriers and facilitators of health behaviors based on the experiences of pregnant mothers and the perspective of health care workers was another strength of this research. Among the many strengths of the current study was that it was a theory-based study, a randomized controlled trial that comprehensively taught common problems during pregnancy and strategies to address them in the form of self-care activities in an educational intervention, whereas other studies have included only some of these, such as changes in diet and physical activity. Another strength of this study was that it identified barriers to and facilitators of health behaviors on the basis of pregnant women’s experiences and health professionals’ perspectives . However, this study also has certain limitations. Considering that the target population in this intervention is limited to primigravida. The focus on a specific population (primigravida women only), could be more detailed to address the implications for generalizability. The effects of educational intervention based on the integration of Pender’s health promotion model and empowerment on self-care behaviors during pregnancy in pregnant women with a history of pregnancy and high-risk pregnant women in need of special care should be investigated in future studies. It has also been proposed to investigate the efficiency and effectiveness of this model in comparison with the efficiency of other models and theories . Knowledge of the various dimensions and aspects of pregnant women’s self-care behaviors can help strengthen pregnant women’s self-care behaviors and lifestyles by formulating policies and planning necessary interventions, and healthcare providers can use health education and programs and effective communication with pregnant women to increase their self-care behaviors. The results of this study could be used as a guide for appropriate policy and planning to remove barriers to and promote pregnant women’s self-care . 

Supplementary Material 1. 

