Breastfeeding in the first six months of life for babies seen by Lactation Consulting

Objective: to identify breastfeeding patterns, survival of exclusive breastfeeding and factors associated with its interruption, in the first six months of life of babies seen by Lactation Consulting. Method: a prospective cohort, with 231 mother-babies in a Baby-Friendly Hospital. An initial questionnaire was applied after 24 hours of birth, after consulting, as well as a follow-up questionnaire, applied by telephone at 15, 30, 60, 120 and 180 days, with sociodemographic and obstetric variables, maternal habits, father’s schooling, birth data and baby feeding. Survival Analysis was carried out. Results: at 180 days of age, exclusive breastfeeding was 12.7% and the probability was 19.6% in the analysis of the survival curve. The factors associated with its interruption were smoking during pregnancy (HR 1.66; CI 1.05 - 2.61), age ≥ 35 years old (HR 1.73; CI 1.03 - 2.90), difficulty in breastfeeding after hospital discharge (HR 2.09; CI 1.29 - 3.41), search for professional assistance (HR 2.45; CI 1.69 - 3.54) and use of a pacifier (HR 1.76; IC 1.21 - 2.58). Conclusion: lactation consultancy contributed to the improvement of the exclusive breastfeeding rates, although there are opportunities for advances.


Introduction
It is a consensus that breast milk is the most complete food for the baby, especially in the first months of life, as it is a source of nutrients in adequate amounts for a developing organism. In addition to being nutritious, breast milk protects against infections, avoids hospitalizations and reduces morbidity from diarrhea and respiratory infections, prevents episodes of otitis media and asthma, and decreases mortality from sudden childhood death syndrome. It has positive effects during adulthood, such as an increase in the intelligence quotient, education and income, as well as it protects against overweight and obesity (1) .
The benefits of breastfeeding also extend to the nursing mother. It is estimated that the expansion of breastfeeding to an almost universal level is capable to preventing 20,000 deaths per year of women with breast cancer, in addition to protecting the lactating woman against ovarian cancer and type 2 diabetes (1) .
The World Health Organization (WHO) adopts definitions of breastfeeding (BF) standards that are recognized worldwide (2) , which are also used in Brazil.
Exclusive breastfeeding (EBF) is defined so when the child receives only breast milk or human milk from another source, without receiving other liquids or solids. When fruit juices, water or water-based drinks are introduced, BF is classified as predominant (PBF).

Complementary breastfeeding (CBF) is characterized
when the child receives any solid or semi-solid food for the purpose of complementing, rather than replacing, breast milk. Finally, mixed breastfeeding (MBF) occurs when other types of milk are introduced than just breast milk.
The increase in the EBF rates has a strong impact on reducing child deaths, estimating that those who are exclusively breastfed have only 12% of the risk of death compared to those who have not been breastfed (1) .
Due to its benefits and the reasons for contraindicating the early introduction of other foods, the WHO and the Ministry of Health recommend BF for two years or more, being exclusively for the first six months of the child's life (2) .
Although the benefits of breastfeeding for the mother-baby binomial and incentive policies are known, the rates remain below the recommended at the baby's sixth month of life (3)(4) . An important strategy to increase the number of children breastfed for the recommended period is lactation consultancy, composed of professionals qualified to provide care to the motherbaby pairs and their families in the management of difficulties with BF (5) . The lactation consultant is certified by the International Board of Lactation Consultant Examiners (IBLCE), after passing an exam offered annually in several countries (6) .
A number of studies indicate that the initiation of breastfeeding and its rates, including EBF, are positively affected by the performance of lactating consultants (7)(8) , in addition to showing that the women seen by these professionals breastfeed for a longer period when compared to those who did not have this intervention (9) .
When considering that the first days after birth are a period in which the greatest concerns about breastfeeding occur and in which women are more susceptible to difficulties in BF (10) , and given the impact of the lactation consultant on the promotion, protection and support of breastfeeding, added to the scarcity of national studies on the performance of this professional, the present study aims to identify breastfeeding patterns, EBF survival and factors associated with its interruption, in the first six months of life for babies seen by lactation consultants.

Method
This is a prospective cohort, carried out with  For the sample calculation, a risk rate of 1.48 and a mean percentage of EBF survival of 5% at the end of six months were used, according to a study on the "maternal age below 20 years old" variable (11) . Considering a power of 80% and a significance level of 5%, the sample size estimate was 210 mother-baby pairs. Estimating 10% losses, the sample consisted of 231 mother-baby pairs. The software used for the sample calculation was WINPEPI, version 11.43.
Two types of instruments were used to collect data. They used primary data, obtained from data collection and that comprised the database of the largest research. Variables that answered to the objectives proposed in this study were used. The dependent variable was EBF interruption in days of the child's life.
The independent variables covered sociodemographic, obstetric and prenatal characteristics, maternal habits, breastfeeding history, baby feeding, difficulties in breastfeeding, reasons for not breastfeeding, offering artifacts to the baby (pacifiers, bottles, cup, spoon and syringe), support in breastfeeding, partner's schooling and birth data.
Data was analyzed using descriptive and analytical analysis. Survival analysis was used to assess the time until EBF interruption in the first six months of the child's life. Data on the mother-baby pairs that were still in EBF at the end of the 180-day follow-up were censored, as well as the data of the pairs that were lost during the follow-up.
To compare the characteristics of the pairs that composed the sample until the end of the study and those whose monitoring was interrupted, the Student's

Results
The study included 231 mother-baby pairs for follow-  Table 1 shows the sociodemographic, obstetric and prenatal (PN) characteristics, maternal habits, breastfeeding history, partner's schooling and birth data of the pairs that made up the sample until the end of the study and those whose monitoring was interrupted.
These investigated variables did not display statistical significance (p≤0.05), which shows that the groups were similar, guaranteeing the quality of the analysis, even in view of the high percentage of losses. The high www.eerp.usp.br/rlae 4 Rev. Latino-Am. Enfermagem 2021;29:e3412.
percentage of women who attended the minimum number of six prenatal consultations (91.6%) was evidenced, without having received information about breastfeeding during the consultations or in a group of pregnant women (62.3%). It should also be noted that the majority of the women were primiparous (67.9%), and that of those with two children or more, 59.4% said they had breastfed their last child for less than six months.       to that obtained in a previous survey (6.6%), carried out 12 years ago, at the same institution (11) , both being cohort studies. Although this increase was significant, it still falls short of what was desired. The percentage found is also higher than that obtained in a study carried out in a Baby-Friendly Hospital in Switzerland, whose probability of EBF at 180 days was approximately 15% (3) .
This increase can reflect the public policies developed over the years in favor of BF, as well as the awareness of women and health professionals about the importance of this practice for the health of the mother-baby binomial.

Discussion
The survival analysis shows that the probability of the baby being in EBF decreased gradually over the  (4) . In an Indian cohort, a similar trend was observed, but with a higher percentage of EBF in the first month (91.7%), reaching 11.4% of the babies breastfed exclusively until the sixth month (15) .
The aforementioned studies made no mention to the support of a lactation consulting team, which can be the justification for the EBF rates to be higher in this study.
This intervention may have contributed to the increase in EBF maintenance until the babies' sixth month of life, since receiving support and guidance on BF during hospitalization has beneficial effects on the EBF rates (7)(8) .
This shows the important role that these professionals play in maintaining exclusive breastfeeding, which has repercussions throughout the babies' lives.
Despite these advances, when compared to the EBF rates in the sixth month of life with international cohorts, it appears that the results are below countries like Canada, with 18.5% of the babies in EBF at six months (13) , and New Zealand, with an EBF rate of 16% in the same period (16) .

However, the index is above the one found in a Saudi
Arabian cohort, with only 2.6% EBF at six months (12) .
However, these studies were not carried out specifically with women seen by lactating consultants, which makes comparisons difficult.
In a systematic review with only randomized studies, it was verified that the interventions performed by lactating consultants have beneficial effects on the EBF rates, in addition to increasing the number of women who choose BF (8) . However, the care offered by these professionals should not be limited to the hospital environment, since the difficulties remain after returning home.
There are factors that can anticipate the introduction of other foods to the babies' diet, which occurred more frequently between 60 and 120 days of life (14.6%). It was possible to verify that, even with the majority of women being between 20 and 35 years old at the time of the interview, those aged 35 or more had a higher risk for EBF interruption before the recommended period. These results are frequent in the literature, although controversial. Corroborating the findings, Italian researchers concluded that older mothers are less likely to breastfeed their children (17) .
The opposite occurred in a study conducted in India, in which the chances of EBF increased with maternal age (18) .
As well as maternal age, smoking is also a factor frequently pointed out in the literature as interfering with EBF. A systematic review points out that nonsmoking women have higher initiation and continuity of breastfeeding when compared to smokers (19) . In the present study, it was verified that 14.3% of the women were smokers during pregnancy, having a 1.66 times higher risk for EBF interruption before the baby's six months of life, when compared to non-smokers. According to a study, most of the women who smoke during pregnancy intend to breastfeed. Despite having a high percentage of breastfeeding initiation, relapse to smoking and early weaning occurred at high rates from 12 weeks onwards, with the most cited reason for interrupting breastfeeding being the perception of insufficient milk production (20) .
However, it is noteworthy that, in the current study, 45.5% of the women smoked from pregnancy to at least the first 15 days of the baby's life. This result was also found in a study, in which 61.7% of the women who claimed to be smoking in the postpartum period also did so during pregnancy (21) . It is known that the volume of breast milk is reduced in smokers, thus shortening the lactation period (19) . In addition, there seems to be mutual protection, since breastfeeding was considered a protective factor against increased smoking in the postpartum period. The longer the women breastfeed their babies, the less they smoke in the postpartum period, that is, investing in effective smoking cessation programs after childbirth can have a favorable impact not only on women's health (22) .
The use of pacifiers after hospital discharge was also evidenced as a factor associated with the interruption of EBF until the babies' sixth month of life, which is a factor frequently cited in the literature.
In an analysis carried out with data from two national surveys, it was possible to conclude that the use of a pacifier was inversely associated with the EBF rates (23) .
Corroborating these findings, a cohort study also reveals that using pacifiers was a risk factor for not consuming breast milk exclusively in the baby's first month (RR = 0.90), in the 4 th month (RR = 1.77) and in the 6 th month (RR = 1.42) (24) . In addition, the use of www.eerp.usp.br/rlae 9 Moraes BA, Strada JKR, Gasparin VA, Espirito-Santo LC, Gouveia HG, Gonçalves AC.
pacifiers increased the number of unfavorable behaviors for the BF practice being considered ideal, especially regarding the body position of the mother and baby during breastfeeding, affective involvement between the mother and her child, suction efficiency and responses of the pair when initiating breastfeeding (25) .
However, there is still no consensus on the mechanism that involves the relationship between pacifier use and early BF interruption. Some authors support the hypothesis that the use of a pacifier can lead to a reduction in the number of daily feedings, causing the baby to be placed less often to breastfeed and, thus, less stimulating milk production (10,23,25) . In addition, the "nipple confusion" is also accepted by many  (26) .
Furthermore, it is not defined in the literature whether the use of a pacifier is a marker of breastfeeding difficulties or a marker of lesser motivation to breastfeed (23) . Following this line, a recent review by the Cochrane Library on the theme concluded that the use of a pacifier, introduced before or after lactation was established, would not affect the duration of exclusive or partial breastfeeding in those mothers who were highly motivated to breastfeed their babies (27) .
Two other factors identified in this study appear to be related: women who had some difficulty in breastfeeding after hospital discharge, who had a little more than twice the risk of interrupting EBF before the baby's six months of life, as well as those who sought help in a human milk bank, consultancy or health unit/office for support in BF due to difficulties in breastfeeding, presented an even higher risk, practically 2.5 times.
The first few days after birth can be decisive for BF success. This is a time when women are most concerned with breastfeeding and when they are more susceptible to breast problems (10) . Among such problems, breast complications stand out, which are among the main causes of food supplementation and early BF interruption (28) . This was also one of the findings of a previous cohort carried out at the same institution, in which it was possible to conclude that a poor breastfeeding technique can anticipate BF interruption in babies under six months old (11) .
These problems often lead women to seek professional help to continue breastfeeding. The active monitoring of the mothers after hospital discharge can offer an opportunity to assess and solve problems with BF, as well as direct them to community breastfeeding resources (29) . Referring the mothers to other breastfeeding support services after discharge from the maternity is essential to sustain the impacts of the HAC on long-term breastfeeding (30) . In a systematic review, the authors concluded that breastfeeding support offered to women has a positive impact on breastfeeding duration and exclusivity (31) .
However, the role of the health professional in issues related to breastfeeding seems to be a barrier to be overcome to offer quality support in post-discharge BF to the women. A study concluded that the health professionals were not sure whether the BF support offered by them was effective and complete, and trusted other colleagues to provide breastfeeding care, which resulted in problematic gaps in the guidelines on the theme (32) .

The authors suggest the development and
improvement of support programs in postpartum BF that incorporate lactation consultants (8) , not necessarily in person. There are alternatives mentioned in the literature to achieve higher rates in EBF, such as counseling by certified lactation consultants, once a week, by telephone contact, starting in the third trimester of pregnancy until one week after the baby is six months old. A study concluded that the women who participated in the intervention group were more likely (97.3%) to breastfeed exclusively until six months than those in the control group (48.5%), indicating that this alternative can substantially enhance and improve practices in BF (9) .
It should be noted that the losses during the follow-up, despite not compromising the quality of the data analysis, constitute a very frequent limitation in longitudinal studies.
In addition, the possibility of memory bias should also be considered, between the occurrence of the studied outcome and the interval of the connection made.
The recognition of breastfeeding patterns, the survival of EBF and the factors associated with its interruption in the first six months of life become important tools in supporting preventive strategies.
With the exception of maternal age, the other factors evidenced by this study are likely to be modified.
Therefore, adequate and qualified management during the pregnancy-puerperal cycle by an updated and engaged team can favor the abandonment of practices that disfavor EBF continuity.

Conclusion
The findings showed a progressive reduction in EBF, as well as a continuous increase in weaning over the first six months of life of babies seen by lactation consultants.
The survival curve revealed that the probability of the baby being in EBF decreased gradually over the time of follow-up. However, there was a significant increase in this probability, when compared to that obtained in a study at the same institution, a little over a decade ago, which may be indicative of the important role played by lactating consultants.
The women who sought basic health units, an HMB (Human Milk Bank) and consultancy after discharge from hospital due to difficulties in breastfeeding were those who presented the greatest risk among those found for EBF interruption before the baby's 6 th month of life.
Therefore, the importance of working in a health network is emphasized, with support after hospital discharge, especially since it is an issue as sensitive and peculiar as BF.
It was also verified that women aged 35 years old or more had a higher risk of interrupting breastfeeding, compared to younger women, a fact that requires extra attention from the health professionals, as well as for those who were smoking during pregnancy.
Finally, the pacifier habit remains a factor linked to early EBF interruption. It is known that this is a habit strongly linked to cultural issues and it is up to the health professionals to warn against the negative contributions of its use to the baby's health and breastfeeding.
There is a contribution of the findings of this study to advancing knowledge on the theme, since lactation consulting is an innovative strategy in health institutions, mainly because it qualifies health care for nursing mothers, babies and their families, in addition to impacting on improvements in the breastfeeding indicators.