Anxiety and its influence on maternal breastfeeding self-efficacy

Objective: to identify the levels of anxiety and breastfeeding self-efficacy in puerperal women at the intervals of 60, 120, and 180 days postpartum; and to verify the influence of anxiety on breastfeeding self-efficacy among these puerperal women. Method: an analytical, longitudinal and prospective study, conducted with 186 puerperal women, and which used a sociodemographic and obstetric characterization questionnaire, the State-Trait Anxiety Inventory, and the Breastfeeding Self-Efficacy Scale - Short Form. The analyses were performed by means of descriptive statistics, and Fisher’s Exact Test was used. Results: most of the puerperal women presented low levels of trait anxiety (55.4%) and of state anxiety (66.2% at 60 days, 72.8% at 120 days, and 75.5% at 180 days), and a high level of self-efficacy (77.3% at 60 days, 75.3% at 120 days, and 72.1% at 180 days of puerperium). Low levels of trait anxiety and state anxiety were associated with high self-efficacy at 60 days (p=0.0142 and p=0.0159, respectively). Conclusion: it is necessary to pay greater attention to the mental health of puerperal women, considering that those who presented low levels of anxiety had higher levels of self-efficacy, a situation that can result in longer exclusive breastfeeding.


Introduction
Adequate nutrition during childhood is considered essential and of great repercussion for reaching better health, nutrition, growth, development, and surviving conditions of the infant, a stage in which breastfeeding stands out as the ideal nutrition source (1)(2) . Breastfeeding is the most efficient action, for it has repercussions in the comprehensive health of both mother and child, in addition to nurturing, reinforcing the bond, and promoting affection and protection, impacting on the health indicators of the entire society (2)(3) .
The National Study on Infant Feeding and Nurturing (Estudo Nacional de Alimentação e Nutrição Infantil, ENANI), which is the most recent research study conducted about breastfeeding indicators in Brazil, observed in its preliminary results an increase in all the prevalence values of this practice in children under five years of age (4) . However, the results showed that we have not yet attained what is proposed by the international and national health institutions (3) .
Despite the scientifically proven evidence of the countless benefits of breastfeeding, a number of studies reinforce that its early interruption still represents a contradiction in Brazil and worldwide (5) . Considering that the puerperium is a relevant period during the woman's life, in which several and significant physiological, psychological, and social transformations occur, it becomes fundamental to monitor the woman's health in this period (6) . Thus, the literature emphasizes the involvement of psychosocial factors, such as maternal breastfeeding self-efficacy and anxiety (7) , as strong determinants for the breastfeeding practice. Maternal breastfeeding selfefficacy is a concept defined as the woman's conviction or trust about her potential or skill to successfully conduct the breastfeeding practice (8) . Women who trust in their ability to breastfeed do so for a longer period when compared to those who lack such self-confidence, turning self-efficacy into an important protective factor for breastfeeding (9) .
Anxiety is defined as a natural and adaptive reaction that can trigger physiological, behavioral and affective reactions, as well as exert an influence on the behaviors. However, it starts to be considered as pathological when those referred feelings are inharmonious to the event that triggers it, or when there is not any specific cause or reason for its emergence (10) .
A number of studies indicate that high anxiety rates in the puerperium are associated with greater chances of not initiating and continuing breastfeeding and, also, of complementation by using milk formulas (11)(12) .
A prospective study revealed a statistical and clinically significant relationship between the anxiety levels and the reduction in breastfeeding duration, highlighting that even the low levels of anxiety should not be neglected because they can be associated with early weaning (13) .
Despite the diverse evidence indicating that high selfefficacy levels have the power to positively influence the maintenance of breastfeeding (14) , and that the presence of anxiety can negatively influence this practice (15) , studies that evaluate the relationship of those variables were not found in the scientific literature. That fact shows that important failures persist, which justifies the conduction of this study. Our hypothesis is that the presence of some anxiety disorder indicator influences the level of breastfeeding self-efficacy.
This study has the following objectives: to identify the levels of anxiety and breastfeeding self-efficacy in puerperal women at intervals of 60, 120, and 180 days postpartum; and to verify the influence of anxiety on breastfeeding self-efficacy among these puerperal women.

Study type
This is an analytical, longitudinal and prospective study.

Data collection locus
Data collection took place in a Basic Health Unit (BHU) of a large city in the inland of São Paulo, Brazil.

Period
The data collection period was between October 2018 and July 2019.

Population and sample
The study population consists of all women at 60 days postpartum, and who were present for the

Selection criteria
The inclusion criteria established were established as follows: women over 18 years old, who were breastfeeding at 60 days, 120 days, and 180 days postpartum. Exclusion criteria were also established, namely: women who had any type of hearing and/or visual impairment which made it impossible for them to answer the instruments, as well as women whose children were receiving any type of special care and/or presented any anomaly or malformation.

Participants
A total of 186 puerperal women took part in the first moment of data collection, 162 in the second moment, and 147 women in the third moment.  from 41 to 60 points, medium anxiety level; and from 60 to 80 points, high anxiety level. For calculation, some questions go through item recoding, that is, in case the answer is 4, a value of 1 is assigned to it in the coding;

Instruments used to collect the information
for a 3 answer, a value of 2 is assigned; if the answer is 2, 3 is assigned; and, if it is 1, 4 is assigned.
The third instrument is the Brazilian version of the Breastfeeding Self-Efficacy Scale -Short Form (BSES-SF), for assessing breastfeeding self-efficacy, validated in a study developed in Brazil with puerperal women in a public maternity hospital (17) , used in this study under authorization by the researcher. Based on the psychometric tests performed for the validation of this scale, it was proven that it can be used in various cultures and age ranges (17) .
The self-efficacy values for breastfeeding obtained by means of the scale are set according to the referred values, and the total scale with 14 items, with a variation from 1 to 5 points for each item, presents a minimum score of 14 and a maximum score of 70 points. Thus, the BSES-SF considers the following: low self-efficacy, from 14 to 32 points; medium self-efficacy, from 33 to 51 points; and high self-efficacy, from 52 to 70 points (17) .

Data treatment and analysis
The participants' characterization was based on descriptive statistics by using the mean and median Rev Latino-Am. Enfermagem 2021;29:e3485.
calculations, standard deviations, minimum and maximum, indicating data variability. To verify the association between the variables, Fisher's Exact Test was used and a 5% significance level was adopted (alpha = 0.05).
The statistical program used was the R program (R Core Team, 2018), version 3.6.1.
It was necessary to group the values obtained for the self-efficacy variables (medium and low) when they were associated with the anxiety (trait and state) variable for visualizing this association. The scores obtained by the participants for low self-efficacy were zero at all research moments, that is, no participant presented low self-efficacy.

Results
A total of 186 puerperal women participated in this study at the first moment, 162 at the second moment, and 147 at the third moment; the mean age was 26 years old, with a minimum of 18 years old, a maximum of 47 years old, and a standard deviation of 6.25. Regarding skin color, brown skin color was referred to by 60.8% of the total participants. In the schooling item, 43.0% of the puerperal women referred having completed High School, and most of them stated professing some religion (76.3%).
Regarding occupation, 49.5% of the participants stated that they perform some paid work outside their homes.
Regarding monthly family income, the mean among the women who declared income was R$ 2,300.45. Regarding marital status, most reported having a partner; of those, 55.9% were in a stable union and 32.3% were married.
In relation to receiving help from someone in caring for the baby, most of the women reported such assistance, with 53.8% receiving from her husband. Of the total participants, 69.9% were exclusively breastfeeding (EMB) at 60 days of puerperium, 51.2% at 120 days, and 25.9% at 180 days.
Regarding self-efficacy, it was observed that most of the women obtained a high level for this variable at the three moments studied, and that rate remained with very similar values at all research moments, as shown in Table 1. Regarding the anxiety disorder, the value obtained by the participants in relation to the answers to the STAI showed that most of the women presented a low level of trait anxiety, as shown in Table 2. It is observed that most of the women had a low anxiety level at the three moments studied.    In the analysis of the association between selfefficacy and state anxiety, the results demonstrate that after 60 days of puerperium, the participants who presented low levels of state anxiety obtained a higher level of breastfeeding self-efficacy, and this analysis was statistically significant (p= 0.0159), as described in Table 5.

Discussion
The breastfeeding self-efficacy levels obtained by most of the participants in this study were considered high at the three moments, with very similar scores, varying from 77.3% at the first moment to 72.1% at the third research moments. Only one woman presented low self-efficacy at the first moment, and no puerperal woman presented that rate at any other moment.
A study on breastfeeding self-efficacy carried out with puerperal women showed results similar to those of this study in 53.4% of the participants (18) .
However, despite high levels of self-efficacy registered after delivery are considered to contribute to better acceptance and adherence to this practice, there is no scientific evidence that high self-efficacy ensures its continuity for a 6-month period or more, given that self-efficacy depends on its four pillars that are variable throughout the days: due to personal experience; due to living together with women who are breastfeeding or had already breastfed; due to the knowledge shared with their support relationship network; and due to their emotional and physical state (19) . In this perspective, early identification in puerperal women of factors involved in the breastfeeding process can assist in specific interventions aiming to keep EMB for longer periods of time (20) .
It is understood from the results found that the and, consequently, better breastfeeding indicators (21)(22) .
Anxiety during the puerperium can be considered as an alarming factor, for it negatively interferes in the affective bond between the mother and her child, reducing the women's ability to cope with the transformations inherent to the period, with the possibility of worsening throughout the child's growth (23) . The literature points out that mothers who present anxiety symptoms report greater complexity to understand their own emotions, which can directly and negatively interfere with the provision of care to the child (24) .
In this study, the results showed that most of the women presented a low level of trait anxiety (55.4%) and also of state anxiety at the three moments investigated (66.2%, 72.8%, and 75.5%). It is suggested that the results are related to the characteristics presented by the study participants, and that they are protective factors for the mental health of these women. Other research studies have shown that women without a partner, with lower schooling, not performing any paid work and with a family income of less than R$ 1,000.00, present higher anxiety levels when compared to the group of women that did not report the same characteristics, corroborating our results and those of other studies in the national and international scope (25)(26) .
The results of the association between breastfeeding self-efficacy and trait anxiety showed that the puerperal women who obtained a low level of trait anxiety presented a higher level of breastfeeding self-efficacy, this result being statistically significant (p=0.0142). In the analysis of the association between self-efficacy and state anxiety, the results showed that, at 60 days of puerperium, the participants that presented low state anxiety scores had a higher level of breastfeeding self-efficacy (p=0.0159). No studies were found that assessed the association between self-efficacy and anxiety. By detecting the conditions that may influence the values of breastfeeding self-efficacy, such as anxiety herein described, health professionals can strategically work with the women and intervene early to promote breastfeeding (27) .
Although the study municipality does not have a specific program aimed at women who present mental disorders, or does not even screen breastfeeding selfefficacy, it can be inferred that the care provided by the Brazil Strategy, an important public policy to encourage breastfeeding that was adopted by this municipality.
One of the limitations of this study was the fact that the presence of anxiety symptoms was not investigated, or any treatment previous to data collection. There was also the unavailability to monitor those participants who were identified with high anxiety levels according to the scale applied and forwarded for better assessment and course of action according to the BHU's protocols. However, the limitations do not imply any loss for the study, for its