Introduction

Down syndrome (DS) corresponds to the most fre quent chromosomopathy¹. In Chile, between 500 and 600 children are born with DS per year, an estimated figure according to annual births in Chile and the birth rate of children with DS of 2.5 per 10,000 live births, according to the Latin American Collaborative Study of Congenital Malformations (ECLAMC)¹.

Children with DS have characteristic phenotypic features and increased risk of congenital diseases and malformations, compared with the general popula tion. It is known that those diseases and physical cha racteristics may interfere with breastfeeding (BF) in this group of patients. The conditions related to greater difficulty in initiating and maintaining BF are hypotonia, suction-swallowing disorders, congenital heart disease, macroglossia, gastrointestinal malformations, hypothyroidism, and intrauterine growth retardation or low birth weight^2,3,4,5. Additionally, there are other cir cumstances that interfere with BF in infants with DS, such as the lack of BF education, prolonged hospitali zations, and the early milk formula indication^4,6. On the other hand, maternal feelings at the birth of a disa bled child, such as stress, frustration, and depression, have been found to have a negative influence on BF^2,7.

The WHO defines the exclusive breastfeeding (EBF) as: “to give the infant only breast milk, without other liquids or solids, except for the administration of oral rehydration salts, vitamins, minerals or medications”⁸. The EBF in this group of patients presents the same benefits that in the general population such as risk reduction of recurrent chest infections, celiac disease, obesity, and cognitive developmental delay. However, it is important to consider that these condi tions are more frequent in the population of children with DS, therefore the benefits are highly relevant. On the other hand, BF would help with the introduction of solid foods and would benefit the language development^{9,10,11,12,13,14}.

The only data on the prevalence of EBF in children with DS in our country come from a nursing thesis stu dy that estimates an EBF rate at six months of 6.25%¹⁵. International publications report variable rates of BF frequency in this group that is not comparable to our population^{6,12,16,17,18,19} or do not report the duration of EBF. In a research carried out in Mexico, it is described a start frequency of BF of 50%¹⁷, and in another study performed in Puerto Rico, the EBF prevalence was 45%¹⁶.

Despite the acknowledged benefits of BF, it is pre sumed that the mother-child binomial with DS adhe rence is lower compared to the general population, thus it is necessary to know the prevalence of EBF in this group of patients and determine the factors that influence their adherence, in order to generate recom mendations and interventions for the promotion of EBF in this most vulnerable group.

The objective of this study is to describe the fre quency of EBF at six months in mother-child bino mial with DS attending at the Health Care Program for People with DS of UC CHRISTUS Health Network (PSSPSD-UC) and identify the main factors associated with EBF cessation.

Patients and Method

This study of prevalence performed in mother- child binomials included Chilean mothers whose chil dren had DS and attend to PSSPSD-UC between Octo ber 2015 and September 2016.

Results

During the study period, out of a total universe of 130 patients invited to participate, 87 mothers who met inclusion criteria expressed that they wanted to parti cipate. A questionnaire was sent to all of them, with a response rate of 83.9% (73/87). Figure 1 shows in de tail the sample collection method and the total sample collected. Table 1 shows demographic characteristics of the 73 mothers surveyed and the background of their respective children with DS.

Figure 1 Sample collection method. 

Table 1 Demographic characteristics of population surveyed. 

The frequency obtained of EBF at six months was 46.6% (N = 34), 30.1% (N = 22) received EBF less than six months, and 23.3% (N = 17) received milk formu la from the first feeding opportunity, in other words, the child never received EBF. Figure 2 shows EBF fre quency by child age. Out of the total mothers surveyed, 95.9% (N = 70) of them breastfed (exclusively or not) for at least one month, and the 71,2% (N = 52) breast fed for six months or more. The 75.3% (N = 55) of them breastfed directly from the breast.

Figure 2 Exclusive, mixed or without Breastfeeding frequency by children age groups. BF Breast Fee ding; EBF: Exclusive Breastfeeding. 

Regarding the reasons for EBF cessation before six months (N=39), 64.1% were because of factors asso ciated to the child with DS (N = 25), 38.5% (N = 15) were due to factors associated to health care, and the 10,2% (N = 4) suspended EBF caused by maternal re asons. The 15.4% (N = 6) of the mothers related more than one reason of EBF cessation. Table 2 shows speci fic reasons for EBF cessation in each group.

Table 2 Reasons for cessation of exclusive breastfeeding before 6 months. 

All the mothers had the prenatal intention of BF her child, and all of them answered true to the state ment that BF is the best food and it protects against diseases.

Out of the total of the mothers, 28.8% (N = 21) of them received prenatal education about BF, the 78.1% (N = 57) received education or support in BF during their stay in the maternity, and the 50.7% (N = 37) received postnatal support in BF, whether in breast feeding clinic or in other support groups. Out of the mothers with previous experience in BF, the 71.7% (33/46) reported having a good previous experience in BF.

75% (30/40) of the mothers had paid work outsi de the home and had maternity leave of six months or more.

15.1% (N = 11) of the mothers had a medical diag nosis of post-partum depression, and the 46.6% (N = 34) of them had feelings of depression in the postna tal period. 41.1% (N = 30) of them reported stress or fear among the prevalent feelings during the first six months of life of their child.

Of the total sample, 67.1% (N = 49) of the chil dren had some pathology or malformation associa ted. The most frequent pathology was congenital heart disease, which represents the 45.2% (N = 33) of the sample.

The 65.8% (N = 48) of the children were hospita lized in the neonatal period, and the 35.6% (N = 26) were hospitalized during the first six months of life.

According to univariate analysis, being only child (p = 0.031), the good previous experience in BF (p = 0.036), the hospitalization within the first six months (p = 0.015), and the use of nasogastric tube (NGT) in the first six months (p = 0.013), would be factors statistically significant for EBF cessation before the six months. Table 3 shows the univariate analysis of EBF frequency up to six months versus EBF frequency less than six months by reason of EBF cessation according to child, mother or health care system factors.

Table 3 Comparison between group that received EBF until 6 months and group with EBF less than 6 months (univariate analysis). 

Table 4 shows the multivariate analysis by logistic regression with three statistical models of EBF fre quency up to six months versus EBF frequency less than six months by reason of EBF cessation according to child, mother or health care system factors. Accor ding to multivariate analysis, the use of NGT and the hospitalization within the first six months would be factors statistically significant for EBF cessation be fore six months with an adjusted OR = 4.00 (CI 95% 1.24-12.94) and 6.13 (CI 95% 1.48-25.40), respecti vely.

Table 4 Multivariate analysis for factors that influence in Exclusive breastfeeding up 6 months or less than 6 months. 

Discussion

This study shows a high frequency of EBF up to six months in the mother-child binomial with DS with a rate of 46.6% of EBF and 71.2% of BF (exclusive or not) up to six months. It is further emphasized that the 96% of the mothers breastfed for at least one month.

Although the EBF frequency in our population was significantly higher than the one reported in the thesis of Quezada in 2001 of 6.25%¹⁵, it is less than the one reported in Chile for the general population that, ac cording to the last National Survey on BF in Primary Health Care (ENALMA), 2013, would reach a 56.3%²¹. ENALMA was conducted after the implementation of the postnatal parental leave Law of 5.5 months, showing an increase of 11.4% since the entry into force of the Law²¹. Such intervention could be also positi vely affecting the study group due to the inclusion of patients in this study after the implementation of the legislation.

International publications report frequency of BF (exclusive or not) in children with DS lower than the one obtained in our population. Rendon-Macias des cribed that, in Mexico, only the 50% of children with DS start BF, and other studies report EBF prevalences close to 45%, without specifying the length of EBF^2,16. Studies that compare BF between children with DS and the general population have shown mixed results. In Italy, Pisacane reported that the 45% of the children with DS are breastfed with an average of 56 days versus an 85% in the controls, with an average of 154 days⁶. On the other hand, in the Netherlands, no significant differences were found in BF frequency in children with DS versus the general population, with a 67% ver sus a 78% respectively¹².

Recent studies have shown that over time, the fre quency of BF in children with DS increase. In 2015, Glivetic reported an increment of 10% from 2009 to 2012, concluding that there are interventions that can be carried out to favor BF in this group¹⁸.

The last report on global prevalence of BF in 2016²², showed an average frequency of EBF up to six months of 37% in low-and middle-income countries, being even lower in the more developed countries. Compa ring it with our results, we obtained a higher frequency than the reported in both EBF and non-exclusive BF up to six months, which makes this indicator conside red a very good result.

Studies in the general population and at-risk po pulations show that the intention of the mother of BF is decisive in order to achieve EBF^16,23. In this study, all the mothers had the antenatal intention of BF and they recognized the benefits of BF. The fact that the child was an only child was a factor that significantly influenced the EBF cessation before six months and despite not obtaining a statistically significant differen ce, we observed that having a good previous experience in BF was associated with a higher frequency of EBF up to six months, which is consistent with what was reported for the general population²¹.

With regard to EBF cessation, the mothers rea sons were the less relevant in this study. In relation to the medical diagnosis of post-partum depression, the prevalence was similar to the reported for the general population²⁴ and it was not a determining factor in the EBF frequency. On the other hand, the antena tal diagnosis or suspicion of DS that could positively affect due to the anticipation and preparation of the mother to the diagnosis, was not a factor that favors the BF, by contrast, in the group with prenatal suspi cion or diagnosis there was a lower frequency of EBF at six months, which may be determined by other added factors in that group such as the presence of congenital malformations associated to DS that led to suspicion of chromosomopathy in the fetal period²⁵.

The most frequent reason referred by mothers to discontinue the EBF was for reasons of the child, mainly associated with sucking-swallowing disorders and poor weight gain, which coincides with tho se described by Colón et al. in Puerto Rico¹⁶. Poor weight gain during the first six months was one of the non-statistically significant factors that negatively affected the BF. On the other hand, the use of NGT (associated with the sucking-swallowing disorder) significantly interfered with EBF in our population, consistent with what was described in the mentioned studies. Although the factors of the child are the most difficult to intervene, it is possible to optimize the BF with an appropriate support and using individualized techniques for each patient and associated pathology or malformation^26,27.

Factors associated with health care, such as the me dical indication of initiation of formula or the mother- child separation due to hospitalization, have been des cribed as relevant to the EBF cessation. In our study, 36% of the children were hospitalized during the first six months, being this a significant antecedent, both in the univariate and multivariate analysis in all models analyzed, in the EBF cessation. During hospitalization, mainly in the Intensive Care Unit, the severity of the pathology and the stress of the mother can negatively impact in the EBF. However, it is possible to promote the maintenance of EBF in the hospital environment through education, promotion of milk extraction and avoiding separation of the mother-child binomial du ring the stay^28,29. Considering the above, this factor is the most modifiable with educational interventions and changes in the pediatric hospital services policies, where facilities could be optimized to maintain the EBF in this group of patients.

One of the main limitations of our work is that the studied population does not represent the natio nal reality since it corresponds to a specific population with a medium-high socioeconomic status, which has access to multidisciplinary care specialized in patients with DS and early referral to a lactation clinic. Despite this, it is important to note that this limitation allows us to infer that targeted and early interventions allow strengthening the EBF in this group of children with special needs. Another limitation is that the mothers who agreed to participate and answered the survey could be those who precisely had the best experience in BF and for this reason were more interested in expres sing it. Finally, to reduce memory bias, we included mothers whose children were two years old or younger at the time of entering the study, however, it is possi ble that at two years of age, mothers did not reliably remember the events that occurred during the first six months of life.

We can infer that is possible to achieve a higher fre quency of EBF up to six months in children with DS, overcoming barriers and limitations of this population through specific techniques and appropriate support to the mothers. There is clear evidence that the support in BF in both, antenatal and postnatal, is effective in order to achieve the EBF in the general population^30,31,32,33, and there are specific techniques that can be used in children with DS^34,35,36 such as: encourage the early skin-to-skin contact, initiation of BF in the first hours of life, educating on positioning techniques with an adequate head and chin support, favoring tongue protrusion, education and exercise through non-nutritive sucking and manual and pumped milk extraction techniques and storage specifications³⁷.

In the future, new studies are required to assess the efficacy of promotion techniques and the support in BF in this group of patients, and thereby encourage the development of intervention methods by health profes sionals, both in outpatient and inpatient settings.

Conclusions

This study shows the high frequency of EBF in chil dren with DS. As a healthcare team, we must be con vinced that children with DS are capable of receiving EBF and with appropriate BF support and education, it can be successful with high exclusivity frequency up to six months.

We recognize that the prevalence of EBF could be even better, so we recommend promotion in BF and generate changes in the main factor described in this study and that is also modifiable, for this we propose: to optimize the comprehensive care of the child with DS that allows to prevent hospitalizations, and in the inpatient environment to educate health professionals about the benefits of the BF in this group, in order to promote it and allow access to BF (direct or expressed), considering the creation of BF rooms and to avoid in terfering with the BF process.

Ethical responsibilities

Human Beings and animals protection: Disclosure the authors state that the procedures were followed ac cording to the Declaration of Helsinki and the World Medical Association regarding human experimentation developed for the medical community.

Data confidentiality: The authors state that they have followed the protocols of their Center and Local regu lations on the publication of patient data.

Rights to privacy and informed consent: The authors have obtained the informed consent of the patients and/or subjects referred to in the article. This docu ment is in the possession of the correspondence author.

Financial Disclosure: Authors state that no economic support has been asso ciated with the present study.

Conflicts of Interest: Authors declare no conflict of interest regarding the present study.