Children's height, health and appetite influence mothers' weaning decisions in rural Senegal

Kirsten B Simondon,a, Régis Costes,a, Valérie Delaunay,c, Aldiouma Diallo,c and François Simondon,b

Institut de Recherche pour le Développement (IRD, formerly named ORSTOM),
a Nutrition Unit, Montpellier, France;
b Infectious Disease Research Unit, Montpellier, France, and
c Niakhar Population and Health Project, Dakar, Senegal.

Reprint requests to: Kirsten Simondon, IRD, BP 5045, 34032 Montpellier Cedex, France. E-mail: kirsten.simondon{at}mpl.ird.fr

Abstract

Background In many developing countries, breastfed children have a lower nutritional status than those weaned from 12 months of age. Reverse causality, that is, earlier weaning of healthy and well-nourished children, is a possible explanation.

Methods Maternal reasons for early and late weaning were investigated in a cohort of 485 rural Senegalese children using structured interviews during two rounds at the ages of 18–28 and 23–33 months, respectively. Length, weight and height were assessed, and dates of weaning were monitored.

Results The mean duration of breastfeeding was 24.1 months (quartiles 21.9 and 26.3). Two-thirds of mothers of breastfed children under 2 stated that they would wean at the age of 2, while for breastfed children aged 2 years, a ‘tall and strong’ child was the most prevalent criterion. The main reasons for weaning prior to 2 years (N = 244) were that the child ate well from the family plate (60%), that the child was ‘tall and strong’ (46%) and maternal pregnancy (35%). The main reasons for weaning later than the age of 2 were: a ‘little, weak’ child (33%), food shortage (25%), illness of the child (24%) and refusal of family food (14%, N = 120). Children breastfed above the age of 2 because they were ‘small and weak’ had lower mean height-for-age and a greater prevalence of stunting than children breastfed late for other reasons (P < 0.0001).

Conclusion The habit of postponing weaning of stunted children very likely explains why breastfed children have lower height-for-age than weaned children in this setting.

Keywords Breastfeeding, weaning, reverse causality, toddlers, stunting, Africa

Accepted 30 March 2000

Maternal motivations for cessation of breastfeeding have received increased attention in recent years because long durations of breastfeeding are associated with an increased prevalence of malnutrition in many developing countries,15 even after adjustment for potential confounders.1,3 Several authors have suggested that this relationship may be due to reverse causality, that is, that mothers prolong breastfeeding when the child is already malnourished.25

Some 25 years ago longitudinal studies in Africa and Latin America provided evidence that the shortest children were the last to be weaned.5,6 Recently, malnutrition (low height-for-age or weight-for-age) prior to weaning has been shown to remain significantly associated with delayed weaning in multivariate analyses adjusting for maternal characteristics.710 In rural Senegal, a clear linear relationship was found between stunting at 9 months of age and the duration of breastfeeding: the prevalences were 6.4, 9.5, 17.6 and 26.6%, respectively, for durations of 12–17, 18–23, 24–29 and 30–48 months (P for trend < 0.0001).10 It seemed very unlikely that residual confounding could be responsible for such a close association. However, we had no direct evidence that mothers considered their children's nutritional status as important for timing of weaning, or that they were able to evaluate height-for-age correctly. Indeed, some researchers have reported or suggested that mothers do not consider nutritional status per se, but rather use developmental criteria such as the child's physical and mental independence from the mother (ability to walk or to eat independently, willingness to be separated from the mother).11,12

In order to further investigate the relationship between nutritional status and duration of breastfeeding, a cohort of young children was followed prospectively from 2 months to about 3 years of age in the same area of rural Senegal. The objective of this paper was to assess maternal reasons for both early and late weaning, defined in relation to the median duration of breastfeeding of 24 months, using interviews with the mothers.

Subjects and Methods

Data collection
The study was conducted in the Niakhar study area in central Senegal, West Africa, which is located about 150 km east of the capital, Dakar. This area is rather densely inhabited by nearly 30 000 people belonging to the Sereer ethnic group, of whom more than 90% are farmers growing millet and groundnuts during the short rainy season from July to October. The main reported religions are Islam (75%) and Christianity (20%). From 1994 to 1996, the infant mortality rate was 77 and the under-5 mortality rate was 182 per 1000.13 Fertility is high, with a total fertility rate estimated at 7.1 live-born children per woman.

Study infants were born from January to October 1995. Prior to home visits, precise birth dates were obtained from the central database together with birth ranks, and age, education and occupation of parents. Dates of weaning, collected weekly until February 1997 and bimonthly thereafter, were taken from the database at the end of the study, in April 1998.

Two home visits were done, in May and October 1997, when the children were aged 18–28 and 23–33 months, respectively. Weight and length (together with height for children aged >=24 months) were measured using standard methods. The data regarding maternal motivations for initiating or delaying weaning were collected by two female interviewers native to the area. In May 1997, mothers of breastfed children were first asked which criteria they would use to evaluate the right moment for weaning (‘How will you know when your child is ready to be weaned?’). This question was open-ended. During both rounds, mothers of weaned children were asked about reasons for weaning, while mothers of breastfed children aged >=2 years were asked about reasons for continuation of breastfeeding. The latter questions proposed lists of reasons, but additional reasons given were noted as well. The lists had been elaborated during a preliminary study conducted in 1995–1996 in the same area among 100 mothers of 24-month-old children, half of whom were weaned. First, lists of reasons for weaning and for prolonging breastfeeding were elaborated after discussions with older women living in the area, and with field workers and research technicians native to the area. Some reasons mentioned frequently in the literature were also included (items 7–8 in Table 3Go and item 5 in Table 4Go). These lists were tested during the preliminary study, and reasons given by several mothers were added (item 4 in Table 3Go). Conversely, the item ‘child aged >=2 years’ was excluded from the list of reasons for weaning because it had been chosen by all mothers, and was thus not discriminating. Finally, the interviewers were instructed not to accept another common answer (‘it was time to wean’). Instead, the mother was asked to explain how she evaluated this. Information about the quality of maternal housing (type of wall and of roof) and the existence of latrines was also collected, and the material used for the walls (mud bricks or cement) was used as an indicator of economic status.


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Table 3 Prevalence of maternal reasons for weaning by the child's age at weaning (%), and duration of breastfeeding (months) by reason
 

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Table 4 Maternal reasons for prolonging breastfeeding beyond 24 months of age (%, N = 120)
 
Among 505 mother-child pairs residing in the study area in May 1997, 485 mothers were present during at least one of the two rounds. Reasons for weaning prior to 24 months were investigated for 244 children out of 248 (98.4%), while reasons for later weaning included 155 children out of 237 (65.1%), since the remaining children were still being breastfed during the second survey. Reasons for prolonging breastfeeding beyond 24 months were investigated only for children aged >=24 months and still being breastfed at the time of the interviews (N = 120, 50.6%). Thus, children weaned prior to the first interview (N = 82), or aged <24 months at the first interview and weaned prior to the second interview (N = 35) were not included since it was not possible to know their exact age at weaning at the time of the surveys.

Statistical analysis
The reasons the mothers gave during the interviews for (1) planning weaning, (2) having weaned and (3) prolonging breastfeeding above the median age of 24 months, were listed by decreasing frequency. Frequency of reasons for having weaned were compared according to the child's age at weaning (<24, >=24 months) and bivariate associations between reasons were tested, using {chi}2 tests or Fisher's exact test. Duration of breastfeeding was compared for each reason for weaning independently, using the Mann-Whitney rank sum test. No global test was performed since several reasons were cited for many children.

Height-for-age was computed using the WHO-NCHS growth reference and Anthro software. Mean height-for-age of 2-year-old children was compared according to the reason for prolonging breastfeeding and age using two-way ANOVA, while comparisons of the prevalence of stunting used {chi}2 tests. All analyses were performed using the BMDP statistical software package.

Results

Characteristics of the sample are given in Table 1Go. Mean age at weaning was 24.1 months (SD: 3.6), and half of the children were weaned between the ages of 21.9 and 26.3 months. Socioeconomic factors associated with a lower mean age at weaning were any kind of maternal education (P < 0.01), a lower maternal age in a nearly linear relationship (P < 0.001) and better housing (P < 0.05).


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Table 1 Characteristics of the sample (N = 485)
 
When the children were to be weaned
The single most important criterion cited for cessation of breastfeeding while the child was still being breastfed and below the age of 24 monthhs was the child's age Table 2Go). The fact that the child was ‘tall and strong’ or ‘ate family food well’ was cited either as the single condition or—more often—as an additional condition paired with age. For children aged >=24 months, a ‘tall and strong’ child was the most prevalent criterion cited.


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Table 2 Criteria mothers planned to use for deciding weaning while their children were still breastfed, by child age at the time of the interview (%)
 
Some mothers planned to wean at the end of the rainy season, just after the harvest (‘in November–December when groundnuts are plentiful and there will be money from the sale of groundnuts to buy food for the child’). The next preferred season was prior to the rainy season, in May–June, because the mothers wanted to leave their child in the compound while doing field work, or because the father would then return from seasonal migration for labour and bring money back.

Several mothers mentioned the child's social behaviour, i.e. his or her ability to play freely with the other children in the compound or to be separated from the mother for half a day without crying. Walking was cited by a few mothers because their children, aged 19–27 months, did not walk well yet.

Why were the children weaned?
The two most frequent reasons for weaning prior to 24 months were that the child ‘ate family food well’ or that he or she was ‘tall and strong’, while the child's age was the most frequent reason for those weaned at 24 months or later (Table 3Go). A ‘tall and strong child’ and ‘ate family food well’ were closely associated (P < 0.0001). Conversely, the ‘tall and strong’ item was less likely to be cited when the child was weaned because of pregnancy (P < 0.0001).

Child-driven weaning and illness of the child were seldom reasons for weaning, and were often related to the mother's pregnancy (P < 0.001 and P < 0.05, respectively). Several mothers explained child-driven weaning during pregnancy by a decrease in breast milk secretion. Four children ill with diarrhoea during their mother's pregnancy were weaned because the mothers believed that their pregnancy had modified the quality of breastmilk and caused the illness. The remaining ill child was weaned because he had been hospitalized for 2 months far from his home.

Maternal illness responsible for weaning was severe: cholera (2), tuberculosis (2), malaria (1) and unknown (2). Maternal migration for labour was a feature of unmarried, primiparous mothers. They left their child in the care of their own mother while working in the capital city, Dakar.

Risk factors for early weaning
Nine children (1.9%) had been weaned prior to 18 months, two because their mother had died, one because of severe maternal illness (cholera), three because of maternal pregnancy and three because their mothers were maids in Dakar. Half (50.6%) of the 85 children weaned prior to 21 months were weaned because of pregnancy.

The children weaned because of maternal pregnancy, migration for labour or illness were weaned significantly earlier than those not weaned for these reasons (P < 0.01, P < 0.001 and P < 0.01, respectively, Table 3Go). Conversely, those weaned because they were ‘tall and strong’ or ‘ate family food well’ were weaned significantly later than the other children (P < 0.001 and P < 0.01, respectively).

Why were some children still breastfed above the age of 2?
The main reasons for prolonging breastfeeding above the age of 24 months were that the child was ‘little and weak’, current or frequent morbidity of the child and food shortage in the household (Table 4Go). Some mothers were not aware that their child was aged >=24 months (range: 24.1–25.1 months). In October, several mothers stated that they avoided weaning because of lack of money and food and because of a high prevalence of illnesses at that time of the year. A low appetite for family food was often reported together with a ‘little and weak’ child: the proportion of ‘small and weak’ children was 59% among those with a low appetite for family food compared to 28% among the remaining children (P = 0.01). No other reasons were significantly associated.

The two cases of relactation after an attempt to wean were motivated by prolonged crying and chronic diarrhoea associated with weight loss, respectively. Maternal concerns were seldom mentioned, though two women aged 39 and 41 years, with parities of 10 and 8, respectively, declared prolonging breastfeeding in order to avoid a new pregnancy.

Height-for-age by reason for prolonging breastfeeding
Children breastfed above the age of 2 years because they were ‘small and weak’ had a significantly lower mean height-for-age (at the age of 24–33 months) than children breastfed above this age for other reasons (P < 0.0001, Figure 1Go). As expected, their mean height-for-age was also significantly lower than that of children in the same age range, weaned prior to the age of 2 (P < 0.001). Interestingly, children breastfed above the age of 2 for reasons not related to their nutritional status had a mean height-for-age similar to that of children weaned prior to the age of 2 (Figure 1Go).



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Figure 1 Mean height-for-age of children breastfed above the age of 24 months either because they were ‘small and weak’ or for other reasons, compared to children weaned prior to 2 years of age

 
The prevalences of moderate and severe stunting (height-for-age between –2 and –3 z-scores and below –3 z-scores, respectively) were extremely high among children breastfed above the age of 2 because they were ‘small and weak’ (31.6 and 23.7%, respectively). For comparison, these prevalences were 13.1 and 8.3%, respectively, for children breastfed beyond this age for other reasons (P < 0.001).

Discussion

This study combined interviews with mothers regarding planned and actual criteria for duration of breastfeeding with precise observations of duration and nutritional status. Planned criteria did not always agree with actual reasons for weaning (results not shown), suggesting that some mothers had cited the cultural norm rather than their precise plans—or that their plans had changed. Some child-related factors, such as height, health and appetite were important for maternal decisions, while others seemed quantitatively less important (dentition, ability to walk and talk). Mother-centred factors such as maternal illness, fatigue and malnutrition were rarely mentioned, probably because of the strong positive value of breastfeeding in this society. Economic factors sometimes delayed weaning, mainly because the mother wanted to give purchased food to her newly weaned child. Very early weaning, prior to 18 months of age, did not seem to be explained by child factors but rather by major maternal events (death, severe illness, pregnancy or migration).

The importance of the child's health in the mother's weaning decision has been described previously, using either interviews with mothers14,15 or epidemiological evidence,8 although in some settings, both health and disease may be reasons for weaning.16 Similarly, the ability to consume the total family diet was a reason for weaning in one setting,15 while a low appetite for family food was a reason for weaning in others.17,18 As far as we know, no studies have yet provided evidence that the child's height affects the mother's weaning decisions directly, although observations in a rural area of Nigeria suggested that ‘sturdy’ children were weaned earlier.5

Data were missing for some of the children. Reasons for weaning were available for virtually all children weaned prior to 24 months, but only for two-thirds of those weaned later than that. However, for children weaned later than the cultural norm, reasons for prolonging breastfeeding were more informative than reasons for weaning. The latter were actually rather misleading, since some children breastfed above the age of 2 because they were ‘small and weak’ finally were weaned when they became ‘tall and strong enough’. Thus, reasons for weaning are difficult to interpret independently of age at weaning.

Reasons for prolonging breastfeeding beyond 24 months of age were only available for those who were still breastfed whilst aged 24 months or more during a survey, since age at weaning was not known precisely at the time of home visits. This design thus biased the sample towards children with the longest durations of breastfeeding (mean: 28.1 months versus 25.6 months for the children not included despite an age at weaning >=24 months, P < 0.001). This is probably why most mothers gave clear motivations for delaying weaning.

Another methodological point to be mentioned is that the use of lists in the investigation of reasons for weaning and for delaying weaning probably increased the proportion of multiple answers, and possibly incited mothers to add reasons which were not essential to them, while reasons not given in the list probably were less likely to be cited. Allowing several reasons per child made interpretation of maternal motivations easier, and allowed for analysis of associations among reasons.

The study confirmed that the children's height-for-age was causally linked to the duration of breastfeeding, and was possibly even more important than their health status. The fact that mothers stated that height intervened in their decisions is a very strong argument in favour of reverse causality. Mothers who considered that their child was not ‘tall enough’, explained that they evaluated his or her height by comparing it to that of other children born at approximately the same time. The analyses showed that these children indeed had very low mean height-for-age, and great prevalence of both severe and moderate stunting.

The interpretation of the mother's perception of a child as ‘tall’, that we give here as being based on height, has been interpreted differently in other studies. Madurese mothers consider their children as ‘big’ when they are physically independent rather than tall.19 For Peruvian mothers, the expression of a big (‘grande’) child encompasses age, motor and language development as well as nutritional status.14 However, these Senegalese mothers consistently stated that the Sereer expression ‘maq’ meant ‘tall for the child's age’, while ‘yal dolé’, strong, referred to the child's physical strength, i.e. ‘strong arms’.

The habit of weaning at the age of 2 years is extremely common in this community, and has also been reported in other Sahelian countries,17 while in Nigeria and Ethiopia, mothers reported that they did not wean at any particular age.5,20 However, this age criterion was modulated according to the child's physical state, in both directions. The mothers' knowledge of their children's age was largely accurate: few mothers of children aged >=24 months stated that their child was younger than that, and these children were seldom aged >25 months. Mothers usually did not recall birth dates, but rather the time of year (season, agricultural calendar) and religious feasts close to the time of birth.

Fathers, and paternal grandmothers seemed to play an important role in maternal decisions, mainly by asking the mother to postpone weaning, and some kind of negotiation between parents was occasionally reported, especially if the child was weaned prior to 2 years or was ill or malnourished. Pregnancy was a frequent reason for early weaning, as described in many other settings,1418,2123 and pregnancy was the only situation in which breastfeeding mothers reported being under pressure from family and neighbours to wean.

In conclusion, this study confirmed the importance of the child's height, health and appetite for maternal weaning decisions. The custom of prolonging breastfeeding when a child is stunted, and of reducing the duration when the child is tall, very likely explains why breastfed toddlers are shorter than weaned children of similar age in this population.

The possibility of reverse causality should be considered in all studies from developing countries comparing breastfed and weaned children in terms of risks of malnutrition, morbidity and mortality.

Acknowledgments

During part of the study period, the Niakhar Population and Health Project was supported by Pasteur-Mérieux Sérums et Vaccins, Paris. The above study was financed by IRD. The authors thank Adama Marra for programming assistance, Agnes Gartner for logistic support, and the participating mothers for their patient and cheerful collaboration.

References

1 Victora CG, Huttly SRA, Barros FC, Martines JC, Vaughan JP. Prolonged breastfeeding and malnutrition: confounding and effect modification in a Brazilian cohort study. Epidemiology 1991;2:175–81.[Medline]

2 Grummer-Strawn LM. Does prolonged breastfeeding impair child growth? A critical review. Pediatrics 1993;91:766–71.[Abstract]

3 Caulfield LE, Bentley ME, Ahmed S. Is prolonged breastfeeding associated with malnutrition? Evidence from nineteen demographic and health surveys. Int J Epidemiol 1996;25:693–703.[Abstract]

4 Prentice A. Breastfeeding and the older infant. Acta Paediatr Scand 1991;374(Suppl.):78–88.

5 Morley D, Bicknell J, Woodland M. Factors influencing the growth and nutritional status of infants and young children in a Nigerian village. Trans R Soc Trop Med Hyg 1968;62:164–95.[ISI][Medline]

6 Mata LJ, Kronmal RA, Garcia B, Butler W, Urrutia JJ, Murillo S. Breast-feeding, weaning and the diarrhoeal syndrome in a Guatemalan Indian village. In: Elliot C, Knight J (eds). Acute Diarrhoea in Childhood. Amsterdam: Elsevier, 1976, pp.311–38.

7 Mølbak K, Gottschau A, Aaby P, Højlyng N, Ingholt L, da Silva APJ. Prolonged breast feeding, diarrhoeal disease, and survival of children in Guinea-Bissau. Br Med J 1994;308:1403–06.[Abstract/Free Full Text]

8 Marquis GS, Habicht J-P, Lanata CF, Black RE, Rasmussen KM. Association of breastfeeding and stunting in Peruvian toddlers: an example of reverse causality. Int J Epidemiol 1997;26:349–56.[Abstract]

9 Fawzi WW, Herrera MG, Nestel P, El Amin A, Mohamed KA. A longitudinal study of prolonged breastfeeding in relation to child undernutrition. Int J Epidemiol 1998;27:255–60.[Abstract]

10 Simondon KB, Simondon F. Mothers prolong breastfeeding of undernourished children in rural Senegal. Int J Epidemiol 1998;27: 490–94.[Abstract]

11 Lauber E, Reinhardt M. Prolonged lactation performance in a rural community of the Ivory Coast. J Trop Pediatr 1981;27:74–77.[ISI][Medline]

12 Brown KH, Dewey KG, Allen LH. Complementary Feeding of Young Children in Developing Countries: A Review of Current Scientific Evidence. Geneva: WHO, 1998.

13 Delaunay V. La Situation Démographique et Epidémiologique dans la Zone d'étude de Niakhar au Sénégal 1984–96 [Demographic and Epidemiological Situation of the Niakhar Study Area in Senegal 1984–96]. Dakar: ORSTOM, 1998.

14 Marquis GS, Diaz J, Bartolini R, Creed de Kanashiro H, Rasmussen KM. Recognizing the reversible nature of child-feeding decisions: breastfeeding, weaning, and relactation patterns in a shanty town community of Lima, Peru. Soc Sci Med 1998;47:645–56.[ISI][Medline]

15 Harrison GG, Zaghloul SS, Galal OM, Gabr A. Breastfeeding and weaning in a poor urban neighborhood in Cairo, Egypt: maternal beliefs and practices. Soc Sci Med 1993;36:1063–69.[ISI][Medline]

16 Jakobsen MS, Sodemann M, Mølbak K, Aaby P. Reason for terminating breastfeeding and the length of breastfeeding. Int J Epidemiol 1996;25:115–21.[Abstract]

17 Dettwyler KA. Breastfeeding and weaning in Mali: cultural context and hard data. Soc Sci Med 1987;24:633–44.[ISI][Medline]

18 Onyango A, Koski KG, Tucker KL. Food diversity versus breastfeeding choice in determining anthropometric status in rural Kenyan toddlers. Int J Epidemiol 1998;27:484–89.[Abstract]

19 Launer LJ, Habicht J-P. Concepts about infant health, growth and weaning: a comparison between nutritional scientists and Madurese mothers. Soc Sci Med 1989;29:13–22.[ISI][Medline]

20 Almedon AM. Infant feeding in urban low-income households in Ethiopia: II. Determinants of weaning. Ecol Food Nutr 1991:25:111–21.[ISI]

21 Bøhler E, Ingstad B. The struggle of weaning: factors determining breastfeeding duration in east Bhutan. Soc Sci Med 1996;43:1805–15.[ISI][Medline]

22 Huffman SL, Chowdhury AKMA, Chakraborty J, Simpson NK. Breast-feeding patterns in rural Bangladesh. Am J Clin Nutr 1980; 33:144–54.[Abstract]

23 Mabilia M. Beliefs and practices in infant feeding among the Wagogo of Chigongwe (Dodoma rural district) Tanzania. II. Weaning. Ecol Food Nutr 1996;35:209–17.[ISI][Medline]