The purpose of this study was to describe the breastfeeding pattern in a sample of Bolivian infants. The results suggest that the rate of exclusive breastfeeding was initially high but then rapidly declined. Use of prelacteal feeds, not feeding the infant colostrum and Latin ethnicity were associated with a shorter duration of exclusive breastfeeding.
Strengths and limitations
To the author's knowledge, the present study is the first to examine socio-economic and biological determinants of the breastfeeding pattern in Bolivia. It also presents data on the diurnal breastfeeding pattern in a less developed country and links actual breastfeeding behaviour with that perceived by the mother as optimal for the infant. The use of only one interviewer increased the consistency of interview management and interpretation of the mothers' answers.
In the current study, the definition of exclusive breastfeeding allowed for prelacteal feed. Prelacteal feed was not an exclusion criterion in the WHO definition of exclusive breastfeeding at the time, in which the absence of food other than breast milk, drops and syrups is required during the 24 hours preceding the enquiry (page 2,
http://www.who.int/child-adolescent-health/New_Publications/NUTRITION/who_cdd_ser_91.14.PDF). With that exception, the rate of exclusive breastfeeding in this study was based on information on the current status and the absence of complementary foods (including milks and other fluids) at any time prior to the present interview. It has recently been shown that data based on current status differ from data based on daily records of feeding[
22], and that long-term recall provides lower estimates of the prevalence of exclusive breastfeeding in infants under 8 months of age when compared to one 24-h recall in cross-sectional studies such as Demographic and Health Surveys[
23]. Different recall methods may be one reason why the data in this study differ from those of McCann et al.[
5,
24], with lower rates of exclusive breastfeeding among infants below 4 months of age in the present study than in theirs (46% vs. 58%). Moreover, most of the infants in this study were of urban origin. This also restricts the possibility of extrapolating the descriptive findings to populations where many inhabitants live in the rural areas, although data on exclusive breastfeeding from the present study correlate well with data from the whole of Bolivia (data from Bolivian Demographic and Health Enquiry)[
16] (Exclusively breastfed: infants ≤ 1 month: 61% (JFL: 64); 2–3 months: 48% (JFL: 37); 4–5 months: 27% (JFL: 27); 6–7 months: 5.2% (JFL: 11); 8–9 months: 2.8% (JFL: 0); and 10–11 months: 0% (JFL: 3.1). (Data from the present study (JFL) were pooled for the purpose of this comparison.). Data in this study may also differ from those of McCann et al.[
5], since data were obtained in different years.
This is a cross-sectional and retrospective study; hence no conclusions should be drawn regarding causal relationships. Nevertheless, some of the findings in this study (such as the negative association between use of prelacteal feeds and duration of exclusive breastfeeding) merit further research, and if verified, they could have important implications.
One possible drawback to the study is that both healthy and sick infants were included. There are no data on whether the infants in this study visited one of the study hospitals in order to receive an immunisation, to attend the well-baby clinic, or to seek assistance due to illness. Although vaccination coverage was around 80% in Bolivia in the mid-1990s and only some 7% of infants in urban areas never received any vaccinations[
16], there is a risk that the reasons for some visits were associated with their feeding pattern[
25]. The risk of bias may be especially great among the older infants, who may have more frequently been brought to the hospital because of illness (and thus, for example, were possibly less likely to be breast-fed). Many of the younger infants were still exclusively breastfed at the time of interview. That was not the case for older infants. This could increase the risk of bias, since the values entered in Cox's regression of actual exclusive breastfeeding duration were more often censored in younger infants than in older infants. More importantly, this sample may not accurately reflect the situation in La Paz as a whole, because it excluded mothers who did not bring their children to the clinics. Illness in the child may also have worried the mother. That could have affected the reliability of her answers.
A number of interviews were interrupted. This caused incomplete data sets. For that reason crude data and actual numbers have, to a large extent, been presented in the present article. Interviews were interrupted at all hospitals and in all social classes, and hence there is little reason to believe that the interruptions would have caused any of the observed associations; it may rather be the case that they blurred the results.
This is an exploratory study where results are data driven rather than conceptually driven. The purpose of the current study was to explore possible determinants of breastfeeding duration, and to do that the stepwise backward regression approach was deemed appropriate. Due to the large number of tests, there is a risk that some statistical significance, particularly those close to p = 0.05, are due to random error rather than representing true findings.
Main findings
The rate of exclusive breastfeeding was initially very high, but then declined rapidly during the second month. This is reminiscent of similar patterns seen in Mexico, Brazil and Honduras[
13]. The radical decline is most unfortunate, keeping in mind that the WHO recently decided to change the recommended duration of exclusive breastfeeding from 4–6 months to 6 months[
26].
In contrast, the rate of any breastfeeding was very high in infants under 1 year of age, and in no age sub-group was it below 85%. This is a very high level compared with reports from Mexico.[
27] and neighbouring Brazil[
28], but it is in line with the high prevalence of any breastfeeding at 7 months in the Simondon et al. study from Bolivia[
6], and data from the Bolivian Demographic and Health Enquiry (97% out of 1115 La Paz women had breastfed their last child.[
29]). In the present study there was no correlation between a range of socio-economic and cultural factors and the duration of any breastfeeding in the previous child. One reason for this may be that the rates of any breastfeeding are equally high in women from all socio-economic strata in the study area. These findings are in contrast to reports from other parts of the world indicating a significant correlation between breastfeeding duration and socio-economic conditions[
12,
30,
31]. Alternative explanations may be the moderate sample size in the current study or lack of accuracy in recalled duration of any breastfeeding. There is also a risk that the assessment used in the current study does not mirror the actual economic situation of the household.
Consumption of prelacteal feeds was strongly inversely related to the duration of exclusive breastfeeding. These findings confirm the report of Perez-Escamilla et al[
32], where both milk-based prelacteal feeds and prelacteal water were negatively associated with exclusive breastfeeding (OR = 0.18 and 0.19, respectively). Similar data have also been presented for Mexico[
33]. The linkage between prelacteal feeds and short duration of exclusive breastfeeding has strong implications. In the present study a relatively small percentage of the infants had been given prelacteal feeds compared with the results obtained for rural Bolivia by McCann and Bender.[
11]. One reason for this discrepancy may be the rather restrictive definition of prelacteal feed used in the present study. Whether prelacteal feeds are given before the very first breastfeed or between the second and third breastfeed is probably irrelevant regarding its impact on infant feeding patterns. It is, however, evident that more knowledge is needed regarding the circumstances surrounding the use of prelacteal feeds. The problem of prelacteal feeds must be confronted.
The discrepancy between actual exclusive breastfeeding behaviour and the perception of how long the infant should be exclusively breastfed is striking. Regardless of the underlying mechanisms, this discrepancy indicates a potential for increasing the rates of exclusive breastfeeding once the mothers' underlying beliefs in this regard have been systematically elucidated. To the author's knowledge, this issue has not been studied previously. Active promotion of breastfeeding may increase both any and exclusive breastfeeding rates, with resulting effects on the risk of diarrhoea, among other things[
34]. The author believes that efforts to inform expectant and breastfeeding mothers are important means for improving infant health both in Bolivia and elsewhere. It has recently been shown that extra professional support is beneficial for both any breastfeeding and exclusive breastfeeding[
35]. All such strategies should also include the discouragement of prelacteal feeds (without this action being culturally offensive) and encouragement to feed infants colostrum.