INTRODUCTION

Breastfeeding has unquestionable advantages for the child and the mother. It is an important strategy for promoting the mother-child bond, and protecting and nourishing the child. It is a sensitive, inexpensive, and effective intervention to reduce infant morbidity and mortality, and promotes the holistic health of the mother-child dyad¹. The World Health Organization (WHO) and the Brazilian Ministry of Health (BMH) recommend exclusive breastfeeding until age six months, and after this age, infants should receive complementary foods in addition to breast milk until age two years or later². For breastfeeding promotion to be successful, engagement of the public authorities is essential. In this sense, the Sistema Único de Saúde (SUS, Unefied Healh Care System) has recorded initiatives at different levels to reduce infant mortality and encourage breastfeeding. However, Brazil is still far from reaching the target recommended by the WHO³.

The advantages of exclusive breastfeeding are acknowledged, but from age six months, the nutritional needs of infants cannot be met by breast milk alone. Promoting the nutritional adequacy of complementary foods in this phase is a determinant in the prevention of childhood morbidity and mortality⁴. However, achieving an appropriate diet for the children should be an essential component of the global strategy to assure the food security of a population. The final success of promoting complementary feeding depends on appropriate governmental policies and the support and participation of the entire society. Nonetheless, health professionals have an essential role in this promotion and can influence appropriate practices when complementary foods are introduced⁵.

The World Health Organization recommends that complementary foods be introduced at age six months in small amounts, increasing gradually as the child grows. From this age onward, the child already has physiological and neurological maturity to consume other foods. Nevertheless, it is important for the child to continue breastfeeding until age two years or more, given that breast milk is nutritious and protects the child from diseases⁶.

Analysis of infant feeding practices is particularly important in not very favorable social development contexts because of its ability to reduce infant morbidity and mortality. Registro is a medium-sized municipality in the state of São Paulo whose Human Development Index (HDI) ranked 199 among the 645 state municipalities in 2010. The municipality is characterized by low income, longevity, and education indices⁷. Hence, the objective of this study is to analyze the situation of breastfeeding and complementary feeding in Registro (SP), in 2011.

METHODS

This analytical, cross-sectional, populationbased study was conducted during the multiple vaccine campaign of 2011 and included children aged less than one year. The study used the methodology proposed by the Projeto Amamentação e Municípios (AMAMUNIC, Project Breastfeeding and Municipalities), whose objective is to collect information about the breastfeeding and complementary feeding profiles of municipalities in the state of São Paulo ⁸.

According to this methodology, all children aged less than one year who participated in the multiple vaccine campaign are eligible for the study, and municipalities with up to 1,500 children the year before the study should conduct the survey on all children⁸. Thus, the present study considered eligible all children aged less than one year who participated in the vaccination campaign to ensure the representativeness of the municipal information.

The exclusive breastfeeding categories and indicators used by the present study are based on a publication by the WHO that provides fifteen indicators for assessing the adequacy of the feeding practices of children aged 0 to 23 months, of which seven are optional⁹. The proposed exclusive breastfeeding indicators also took into account the recommendations of the Food Guide for Children aged less than two years¹⁰. Some adaptations were necessary because the study included children aged less than one year (the indicators proposed by the WHO include children aged up to 24 months). Furthermore, since the questionnaire was administered during the vaccination campaign, it had to be administered quickly not to interfere with the vaccination, so the intake of foods 24 hours before the interview was not investigated as thoroughly as required by the WHO, imposing some limitations on the construction of the indicators.

The outcomes of the present study were defined as follows: exclusive breastfeeding when the child is given breast milk, oral rehydration fluids, and/or vitamin, mineral, and medication drops or syrups from ages 0 to 6 months; and correct introduction of complementary feeding when the child is given fruits and a savory mash from ages 6 to 9 months.

The study child characteristics that could possibly affect the outcomes of interest were: gender (female/male), low birth weight (yes/no), type of delivery (vaginal/caesarian), breastfed in the first hour of life (yes/no), exclusive breastfeeding on the first day at home (yes/no), use of bottle (yes/no), use of pacifier (yes/no), and follow-up at a health care facility (SUS or private). The mother-related explanatory variables were: age (<20; 20-35; and >35 years), number of parturitions (primiparous/multiparous), employment status (works away from home/does not work away from home), and education level (<8 years; 8-11; >11 years).

The study indicators were descriptively analyzed by calculating the proportions. The median exclusive breastfeeding and breastfeeding were given by logit analysis, which uses statistical modeling to estimate the probability of the study event as a function of the child's age¹¹. To assess the association between the explanatory variables and the outcomes, crude and adjusted analyses were done using Poisson regression with robust error variance given that this is a cross-sectional study and the outcomes are not rare¹². The variables with p<0.20 in the simple regression were included in the multiple model. The data were analyzed by the software Stata 10.1.

The study protocol was approved on May 6, 2008, by the Research Ethics Committee of the Institute of Health under Protocol number 001/2008.

RESULTS

The population of children aged less than one year in the municipality of Registro (SP) in 2011 was 871, and 836 were vaccinated, resulting in a vaccination coverage of 96.0%. We collected data from 723 children, of which ten (1.4%) were excluded from the analysis because their birth date was missing. The total study sample was 713 children, representing coverage of 86.5% children of the age bracket of interest. In relation to the sample, 89.4% of the children lived in urban areas, 94.5% lived in Registro (SP), and 87.7% were accompanied by their mothers.

Table 1 shows the distribution of the sample according to the children's and mothers' characteristics. Gender distribution was similar.

Most children were delivered vaginally (normally or through the use of a forceps), but the caesarian rate was high at 43.7%. The proportion of exclusively breastfed children on the first day at home after hospital discharge was high, although more than half of the mothers reported using a bottle and 40.0% had used a pacifier the day before the interview. Most mothers were aged between 20 and 35 years, did not work away from home, and had 8 to 11 years of formal education.

Figure 1 shows the exclusive breastfeeding and breastfeeding probabilities according to the children's ages. The exclusive breastfeeding rates plummeted during the first days of life. After ninety days, the probability dropped to less than 50%, and at 180 days, the probability of being exclusively breastfed was around 13%. The probability of breastfeeding remained higher than 70% up to 180 days of life, dropping to 47% of the children at around age one year. The median durations of exclusive breastfeeding and breastfeeding were 79.7 days (95% Confidence Interval-95%CI=67.66-90.36) and 350.23 days (95%CI=312.96-406.39), respectively.

Figure 1. Probability of children aged less than one year being Exclusively Breastfed (EBF) and Breastfed (BF). Registro (SP), 2011. 

Table 2 shows the breastfeeding and complementary feeding indicators of the study population. Most children were breastfed in the first hour of life after delivery, half the children aged less than six months were being exclusively breastfed, and 60% continued to breastfeed at the end of the first year of life (between 9 and 12 months).

The complementary feeding indicators showed that 62.0% of the children aged 6 to 8.9 months consumed fruits and at least one savory meal, as recommended by the BMH, and only 35.0% received at least one savory meal between ages 6 and 6.9 months. Thirty-nine percent of the children aged 8 to 11.9 months were given foods prepared for the family. The high consumption of high-iron foods was surprising. On the other hand, more than three-fourths of the children were given at least one unhealthy meal in the 24 hours that preceded the interview, namely cookies/biscuits or chips (63.7%), foods with added sugar (40.4%), drink mixes (22.4%), coffee (8.2%), and soda (7.1%).

Table 3 shows the proportions of exclusively breastfed children aged less than six months, the respective Prevalence Ratios (PR), and crude and adjusted 95%CI by maternal and child characteristics. In the crude analysis, female infants, infants delivered vaginally, infants who were breastfed in the first hour of life, multiparous mothers, mothers with more education, mothers who were followed at SUS, and mothers who did not work away from home had PR higher than 1, but p>20 kept them out of the multiple model.

The variables low birth weight, exclusive breastfeeding on the first day at home, use of pacifier, and maternal age had p<0.20, so they were included in the multiple regression model. In the final model, the prevalence ratios for exclusive breastfeeding were significantly higher among children who were breastfed on the first day at home (PR=2.40; 95%CI=1.42-4.06) and those who did not use pacifiers (PR=1.95; 95%CI=1.15-3.30).

Table 4 shows the proportions of children aged 6 to 8.9 months given complementary foods (fruit and savory meal) and their crude and adjusted PR and 95%CI according to maternal and child characteristics. In the exploratory analyses, children more likely to receive proper complementary foods were males, children born with appropriate birth weight, children given bottles, and children not given pacifiers. Additionally, primiparous and older mothers were more likely to offer complementary foods, but these variables were not included in the final model because their p>0.20. The variables included in the multiple model were: follow-up at a health care facility and maternal employment status and education level, but in the final model none of the variables remained statistically associated with the outcome.

DISCUSSION

The prevalence of exclusive breastfeeding in Registro (SP) was higher than that of Brazilian capitals and Distrito Federal (41%), of the Southeast region (39.4%), and of the municipality of São Paulo (39.1%)¹³. It was also higher than those of 227 municipalities that conducted the II Survey on Breastfeeding Prevalence in 2008¹⁴, but it is still far from the WHO recommendations². Meanwhile, the prevalence of breastfeeding at the end of the first year of life was similar to that found by the II Survey on Breastfeeding Prevalence (II PPAM/2008)¹³.

An eye-catching fact is the sharp decrease in the probability of exclusive breastfeeding as the child grows older, a trend also found in the municipality of Itapira, where only 9.6% of the children aged 121 to 180 days were being exclusively breastfed¹⁵, and Campina Grande (PB), where the prevalence of exclusive breastfeeding dropped from 20.9% in the third month to 8.3% in the sixth month¹⁶.

Exclusive breastfeeding on the first day at home after hospital discharge indicated a higher likelihood that the child would be exclusively breastfed in the first six months of life, a finding also reported by other studies^{15 , 17}. Another factor associated with exclusive breastfeeding was not using a pacifier, corroborating many domestic studies^{17 - 21}. These findings reinforce the importance of the information provided by maternity hospitals and the Baby-Friendly Hospital Initiative, which contemplates the Ten Steps to Successful Breastfeeding and the non-use of artificial teats and/or other fluids or foods besides breast milk²². Venancio et al.²³ and Vieira et al.²⁴ found that being born at a Baby-Friendly Hospital and receiving information at maternity hospitals increase the probability of exclusive breastfeeding in the first months of life.

The prevalence of breastfeeding in the first hour of life in Registro (SP) was also higher than those found by the II Survey on Breastfeeding Prevalence in Brazilian capitals and the Distrito Federal (67.7%)¹³, by the Pesquisa Nacional de Demografia e Saúde 2006 (PNDS, National Survey about Demographics and Health) (43.0%)²⁵, and by other regional studies^{26 , 27}. This finding is very important because there is evidence that this practice can reduce neonatal mortality^{28 , 29} and encourage exclusive breastfeeding³⁰.

The complementary feeding indicators showed that only two-thirds of the mothers followed the BMH recommendations regarding the introduction of fruits and savory mashes after age six months. We also found inadequacies regarding the children's meal frequency and preparation. If on the one hand almost all children aged 6 to 12 months were given high-iron foods, on the other hand more than 70% of the children were given unhealthy foods.

Domestic studies on complementary feeding are scarce and use different indicators at different age groups, which impairs comparing the results. However, all studies found significant inadequacies: the II PPAM/2008^*3 found that more than one-fourth of the children aged 6 to 9 months were not given savory foods; likewise, the PNDS/2006²⁵ found that 64.4% of the children aged 6 to 8 months had been given savory foods; some domestic studies also reported the early introduction of complementary foods, that is, before the child is six months old^{31 - 33}.

Domestic studies on the intake of highiron foods disagree. A study conducted in the urban area of the municipality of Acrelândia in the state of Acre with 164 children found that the proportion of children aged 9 to 11 months with low iron intake was 94%, while a study conducted in the fourteen poorest municipalities of the state of Paraíba with children aged 0 to 23.9 months found that 70% of the children were consuming high-iron foods³⁴.

A prospective study in the cities of São Paulo (SP), Curitiba (PR), and Recife (PE) found early the introduction of unhealthy foods, such as packaged sweets, sandwich cookies, instant noodles, TV dinners, soda, and drink mixes³⁵. Population-based foreign studies that assessed the food intake of American and European (German, Polish, Italian, Spanish, and Belgium) breastfeeding infants also reported the use of inappropriate foods for this age group, such as high-fat and high-sugar foods^{36 - 38}.

The absence of an association between the explanatory variables and the complementary food indicator could partly be explained by the small number of children in this age group, which consists of a study limitation. Another limitation consists on the fact that the survey was conducted on a single day during the vaccination campaign, imposing restrictions on data collection.

Notwithstanding, some positive methodological aspects deserve to be pointed out, as the methods are a widely recommended and used strategy in Brazil because of their ease of use, and low cost, and the broad coverage of vaccination campaigns³⁹. Hence, the results are representative of the population of infants aged less than one year from the municipality of Registro (SP) and can contribute to the planning of interventions that aim to increase breastfeeding practice and the use of healthy complementary foods.

The non-adherence of the municipality of Registro (SP) to the various strategies proposed by the National Food and Nutrition Policy and National Child Health Policy is a factor that should be considered when analyzing the results. Thus, among the possible interventions, we can suggest the implementation of the Baby-Friendly Hospital Initiative because of its impact on breastfeeding indicators, and the Brazil Breastfeed and Feed Strategy, resulting in the integration of the Brazil Breastfeed Network and the National Strategy for Promoting Healthy Complementary Foods (ENPACS), whose objective is to promote breastfeeding and healthy complementary foods at the primary care level⁴⁰.

We also hope that the results of this study help to generate hypotheses for future studies on the theme and contribute to increase the knowledge on the profile of complementary feeding practices in our medium, given that few studies have approached the correct introduction of complementary foods in the first year of life.