Impact of the Brazilian national breast-feeding programme on mothers in greater São Paulo.

Impact of the Brazilian national breast-feeding programme on mothers in Greater Sao Paulo M.F. Rea' & E.S. Berqu62 A broad-based national breast-feeding programme was launched in Brazil in 1981 that was preceded by an evaluation of infant feeding habits in two metropolitan areas of the country. This paper reports the initial findings of an evaluation of the programme in Greater Sao Paulo that was carried out in 1987, 6 years after the programme started. The method employed was analogous to that used before the start of the programme in 1981. For this purpose, a representative sample of mothers who were attending child care services open to all income groups were interviewed, together with a number of health professionals. A total of 497 mothers with children aged 0-12 months were covered. A recall interview was also administered on the duration of breast-feeding for all children born to the mothers since 1981. As a result of the programme, the mean duration of breast-feeding rose from 89.4 days to 127.5 days and of feeding only breast-milk from 43.2 days to 66.6 days. The proportion of previous children who were breast-fed for more than 6 months rose from 18.9% for those born in 1981-82 to 37.7% for those born in 1984, when the programme activities were at their highest, and slipped back again to 27.6% in 1985-86. Introduction A considerable number of reports have appeared on programmes and projects designed to encourage breast-feeding (1). Since the evidence began to accumulate several decades ago that breast-feeding is important for children's health and even survival (2), several countries have set up programmes to promote breast-feeding. It is crucial that for a given country or region the most appropriate ways of planning and implementing such programmes be identified and that their impact be investigated. In general, the majority of breast-feeding pro- grammes have been carried out at the institutional level, with a definite clientele. The activities that such programmes have focused on to promote and sup- port breast-feeding include the following: midwives, nurses, and physician's education (3); home visits provided by a lactation counsellor (4); and modifica- tions to the health services routines, such as early mother-infant contact (5) or rooming-in (6). The results of these activities can be determined relatively easily by comparing breast-feeding data collected before and after the start of a specific intervention. Evaluations of this type are not difficult to carry out, ' Director, Division of Maternal and Child Health, Instituto de Saude, Sao Paulo State Secretariat for Health, Brazil, and Researcher, Centro Brasileiro de Analise e Planejamento (CEBRAP), rua Morgado Mateus, 615, CEP 04015 Sao Paulo, Brazil. Requests for reprints should be sent to the latter address. 2 Director, Population Programme, CEBRAP, Sao Paulo, Brazil, and Director, Nucleo de Estudos de Popula,ao (NEPO), State University of Campinas, Campinas, Brazil. Reprint No. 5084 provided the population has the same demographic structure both before and after the intervention, and other aspects that could influence the results are also taken into consideration. In contrast, breast-feeding programmes that include activities directed at pro- tecting lactating women, such as national policies or mass media campaigns, are more difficult to evaluate. Clearly, as the complexity of the proposed interven- tions increases, the smaller are the chances that the programme will be correctly evaluated. In Brazil, the national breast-feeding pro- gramme was disseminated mostly through the mass media, although other activities were also carried out. It is difficult to measure the impact of programmes of this type in view of the large number of factors that can affect a mother's decision to breast-feed. The most suitable gauge is how much the duration of breast-feeding increases. In the evaluation of this impact, the effect of breast-feeding on indicators of infant morbidity and mortality can also be taken into account. In the early 1980s, the Ministry of Health and the local UNICEF office were convinced that the early weaning rate was alarmingly high in Brazil and that it was important to tackle this problem through a campaign in the mass media. The result was the creation of the national breast-feeding promotion programme, which relied heavily on the mass media but also used other strategies. These included: pro- vision of health professionals with up-to-date infor- mation on breast-feeding; encouragement of research activities and scientific meetings on breast-feeding; efforts to motivate and educate health workers on breast-feeding management; implementation of the rooming-in system in clinics; inclusion of information Bulletin of the World Health Organization, 68 (3): 365-371 (1990) © World Health Organization 1990 365 M.F. Rea & E.S. Berqu6 on breast-feeding in the training curricula for health personnel and primary grade teachers; preparation and implementation of a code of marketing of breast- milk substitutes based on the WHO/UNICEF Inter- national Code of Marketing of Breast-milk Sub- stitutes; enforcement of existing laws that protect the rights of working mothers during pregnancy and lactation; provision of incentives to mother's groups; efforts to increase awareness about the consequences of weaning; and the creation of procedures for infor- ming mothers about breast-feeding, either personally or through the mass media (7). In order to determine what impact the pro- gramme had achieved and any difficulties that had been encountered, the Ministry of Health-through the National Food and Nutrition Institute (INAN) and UNICEF-supported an evaluative study of the programme (8). For this purpose, the Centro Brasileiro de Analise e Planejamento (CEBRAP) first carried out an evaluation of the breast-feeding rates and services available in 1981, before the programme was implemented, in Greater Sao Paulo and Greater Recife. The services provided to all income groups were investigated. The second stage of the evaluation was carried out in 1987, and involved an assessment of the situation after implementation of the programme. Here, we describe the initial findings on the impact of the programme on the duration of breast- feeding in Greater Sao Paulo. Materials and methods Population and sample The sampling procedures used in the 1987 evaluation were the same as those employed in 1981, before the implementation of the programme. The services were first chosen by lot from a computer print-out of all those provided for healthy children in Greater Sao Paulo, in numbers proportional to the demand for them and to their representativeness, according to the income brackets described below. * Group I-low income: health centres run by the state government, by the Sao Paulo city government, and by the federal health service. * Group II-middle income: clinics belonging to private insurance schemes paid for by employers and employees. * Group III-high income: private consultants and clinics or hospitals covered by private medical insurance schemes. A list of 500 mothers with infants aged 0-12 months was then drawn by lot from those attending the above-mentioned health services for healthy child care. A questionnaire was used to record the results of interviews with eligible mothers, who were selected by lot on the day of the interviewer's visit to the health centre. Finally, a sample of paediatricians, obstetricians, and nurses was also interviewed at the health centres, and the routines used were recorded. Data collection The questionnaire that was administered to the mothers was designed to evaluate the feeding pro- cedures that were being practised with the current infant, in terms of the following variables: demo- graphic (age, parity, etc.), socioeconomic factors, breast-feeding habits, reproductive life, work aspects, impact of health services, and exposure to the breast- feeding promotion campaign. In order to evaluate the extent of total breast- feeding of previous children born to multiparous women from 1981 onwards, the questionnaire included an inventory of the duration of breast-feed- ing for each previous child born after the start of the programme. Study hypotheses The study hypotheses outlined below were inves- tigated. * The number of women starting to breast-feed was greater in 1987 than it was in February 1981. * The number of women feeding only breast milk throughout infancy was greater in 1987 than it was in February 1981. * Children born since the programme began were breast-fed for longer than those born beforehand, and this effect increased with the length of time that the programme ran. * Women who weaned their infants early were less exposed to the activities that were developed or encouraged by the programme. Methodological considerations for the analysis The breast-feeding campaign began in the mass media on 5 March 1981 and continued till December 1986 with short periods of greater intensity and changes in the messages involved. It was therefore decided to proceed as outlined below. * The baseline data for the study were obtained from the initial evaluation that was conducted in January and February 1981, before the programme started (8). * In the 1987 assessment, the mothers were asked how long they had breast-fed all children born to them (irrespective of whether they were currently alive or dead) since 1981. The quality of these retro- WHO Bulletin OMS. Vol. 68 1990.3w Impact of the Brazilian natlonal breast-feeding programme In Greater SAo Paulo spective data varied, in so far as the interval between the breast-feeding episodes tended to make the mothers round off the periods (e.g., to 3 or 6 months) over which they had breast-fed their older children. Furthermore, the answers given by mothers who had several children were probably less reliable (because of confusion) than those given by mothers with fewer children. e An additional problem that arose in making com- parisons between data from different years was that many of the youngest children (including the index children, who were aged 0-12 months) were still being breast-fed when their mothers were inter- viewed. Data on the duration that these children were breast-fed were therefore not included in the, analysis. It was therefore decided to study the 497 index children separately, using the "current status method" (9) and to compare birth cohorts year-by- year for those born between March 1981 and May 1986 (334 children). In this way, all the children, living and deceased, were covered. * As mentioned above, the intensity of the breast- feeding campaign varied, and the following "waves" could be identified, i.e., periods when greater coverage was given to it on radio and television: -March 1981 to July 1982 (the campaign organized by the Ministry of Health); -August 1982 to December 1983 (the campaign organized by UNICEF and the Ministry of Health); -January 1984 to December 1984 (no systematic airing of any breast-feeding promotional material, but reinforcement of several other activities of the programme); and -January 1985 to December 1986 (no nationwide coordination of the programme). Four cohorts of children were therefore studied in accordance with their month of birth and its relation to the above-mentioned waves, as well as taking into consideration the stage during which the programme was being phased out. * In so far as all mothers included in the sample had to have an index child aged 0-12 months, those with children in one or more of the cohorts were neces- sarily multiparous. The fourth cohort was made up of children born at much shorter interpartal intervals than the others. This should be borne in mind in evaluating the period during which these infants were breast-fed, since they may have been weaned because of a new pregnancy (10). * The analysis based on the child's year of birth focuses not on the mother but on the child. Thus, a mother's accumulated experiences with breast-feed- ing were not taken into account, even though-as shown by the results of the pre-campaign evalua- tion-success in breast-feeding the immediately preceding child determined the outcome of breast- feeding the next (8). The definition of exclusive breast-feeding used here includes all infants who received breast milk only, but such infants were not excluded if they also received tea, water, or juice. Results Breast-feeding of the Index children Information on the breast-feeding status at the time of the interview was obtained from 497 mothers of children aged 0-12 months (index children). Data for children aged more than 8 months were omitted to ensure that the same basis was used as in the 1981 assessment before the national programme began. Of the 380 index children aged 0-8 months, 360 (94.7%) had started being breast-fed, compared with 91.3% in 1981. The difference was not statistically significant. Furthermore, 63% (227 out of 360) of the children were being breast-fed at the time of the interview in 1987, compared with 41.2% in 1981. This difference was significant (X2 test = 29.77, P <0.005). In 1987, the prevalence of exclusively breast-fed children, i.e., the only milk they received was from the breast, was 48.9%, which was an increase, albeit not significant, from the 41.6% of such children identified in 1981 using an identical method. The current status method was used to obtain unbiased estimates of the average duration of breast- feeding. Of the 227 mothers whose children were being breast-fed at the time of the interview in 1987, the average duration was 127.5 days (Table 1). In 1981, it was 89.4 days. Between 1981 and 1987 the average period of feeding only breast milk also increased considerably, from 43.2 days to 66.6 days (Table 2). Breast-feeding of previous children The replies to interviews with multiparous mothers were used to determine the duration of total breast- feeding for all living and deceased children born since 1981, when the programme started. This covered 334 children, subdivided according to the stages of the programme outlined above. Table 3 shows the frequency of breast-feeding for greater than 3 or greater than 6 months for children born during the various stages of the programme, as well as the breast-feeding frequency of the penultimate children born to multiparous moth- ers before the start of the programme. It must be stressed that, since there is no way of determining the dates of birth of these penultimate children, the data WHO Bulletin OMS. Vol. 68 1990. 367 M.F. Rea & E.S. Berqu6 Table 1: Distribution of the duration of breast-feeding among the Index children In Greater Sbo Paulo before and after the Brazilian national breast-feeding programmea Before 1981: After 1987: Age No. of Proportion No. of Proportion (days) children observed breast-fed children observed breast-fed 1-14 3 1.004 11 1.00 15-21 5 1.00>0.95)a 13 0.85 (0.91) 22-30 11 0.91.) 21 0.90) 31-60 55 0.47 64 0.81 61-90 46 0.33 52 0.75 91-120 51 0.29 41 0.46 121-150 40 0.38 65 0.41 151 -180 36 0.31 32 0.50 181-240 51 0.25 81 0.41 Total 298 2.98b 380 4.25c a Figures in parentheses are the mean proportion of infants who were breast-fed for the first 30 days. b Mean duration=89.4 days. c Mean duration=127.5 days. Table 2: Distribution of the duration of feeding only breast milk among the Index children In Greater Sao Paulo before and after the Brazilian national breast-feeding programme Before 1981: After 1987: Age No. of Proportion No. of Proportion (days) children observed exclusively breast-fed children observed exclusively breast-fed 1-14 3 1.00) 11 0.54) 15-21 5 1.00 (0.74)' 13 0.46 }(0.53) 22-30 11 0.54 21 0.57J 31-60 55 0.24 64 0.44 61-90 46 0.11 52 0.33 91-120 51 0.04 41 0.39 121-150 40 0.10 65 0.12 151-180 36 0.11 32 0.37 181-240 51 0.10 81 0.14 Total 298 1.44b 380 2.22c ' Figures in parentheses are the mean proportion of infants who were breast-fed for the first 30 days. b Mean duration=43.2 days. c Mean duration =66.6 days. involved do not apply to the breast-feeding practices for a specific period in Sao Paulo. Table 3 shows that the proportion of infants who were being breast-fed had dropped in 1981-82, with those who were breast- fed for more than 6 months accounting for only 18.9% and those who were breast-fed for more than 3 months, 27.8%. In the second half of 1982 the second stage of the campaign began; 52.1% the 96 children born during this phase were breast-fed for more than 3 months, and 34.4% for more than 6 months, i.e., the propor- tion was almost double that during the first stage. The proportion of infants who were breast-fed for greater than 3 or greater than 6 months dropped in 1985-86 to 46% and 27.6%, respectively. This cor- responded to the period when the programme was being phased out as a nationwide campaign. The data were also analysed in terms of whether or not the mothers had seen the breast-feeding publicity material in the mass media during the campaign. Table 4 contains the results for the two groups of mothers, i.e., those who saw the advert- isements and those who did not. In 1981-82, only 17.0% of the children who were breast-fed for more than 6 months were born to mothers who saw the advertisements, compared with 22.6% for those chil- dren whose mothers did not see them. The data for mothers who had seen the cam- WHO Bulletin OMS. Vol. 68 1990.368 Impact of the Brazilian national breast-feeding programme In Greater Sio Paulo Table 3: Frequency of breast-feeding for >3 months or >6 months according to the Infants' year of birth and the "waves" of the Brazilian national breast-feeding programme, Greater Sio Paulo Frequency of breast-feeding (%) >3 >6 Total Year of birth months months number' Before 1981 38.5 24.4 156b 1981-82 (first wave) 27.8 18.9 90 1982-83 (second wave) 52.1 34.4 96 1984 (third wave) 60.6 37.7 61 1985-86 (fourth wave) 46.0 27.6 87 Total - - 334 ' Mothers with more than one child who were interviewed. b Mothers with more than one child who were interviewed before the programme began. Table 4: Proportion of Infants who were breast-fed for more than 6 months, according to their year of birth and whether their mothers were exposed to the breast-feed- Ing advertisements campaign, Greater Sao Paulo Campaign advertisements: Exposed' Not exposed" Year of birth % No. % No. 1981-82 17.0 59 22.6 31 1982-83 32.2 62 38.2 34 1984 40.0 35 36.0 25 1985-86 25.4 51 30.5 36 Total - 207 - 126 a The statistical tests used are described in the text. paign were first broken down additively into three degrees of freedom using Cochran's method (11). The results below show the proportion of infants who were born to such mothers and were breast-fed for more than 6 months. The statistical analysis was carried out using the x2 test with one degree of freedom for each one of the following comparisons: -1982-83 versus 1984: 32.2% versus 40.0% (X2 =0.587, not significant); -1981-82 versus 1982-83 plus 1984: 17.0% versus 35.0% (X2 = 5.940, significant); and -1982-83 plus 1984 versus 1985-86: 35.0% versus 25.4% (X2=0.319, not significant). The campaign from 1982 to 1985 therefore increased significantly the proportion of infants who were breast-fed for more than 6 months. A similar analysis of the data for those mothers who had not seen the campaign indicated that there were no statistically significant differences in the proportion of infants who were breast-fed for greater than 6 months. This indicates that the proportion of children who were breast-fed for more than 6 months was independent of birth cohort during the period 1981-86. Analysis and conclusions The lack of impact of the national breast-feeding promotion programme on the start of breast-feeding arose because 91.3% of mothers had already begun breast-feeding when the programme was first implemented. Nevertheless, the programme prompt- ed 3.4% more mothers to begin breast-feeding, bring- ing the proportion (94.7%) close to the biological limit, i.e., the level at which breast milk is not produced or where breast-feeding can only proceed with extreme difficulty.' These proportions are com- parable with those found in all previous studies in Brazil, where the infant feeding practices are charac- teristic of those in less developed countries. The impact of the programme is made clear by the fact that the average duration of total breast- feeding increased by 38 days (from about 3 months to 4.3 months), while the duration of feeding only breast milk rose from 43 days to 67 days. As far as the total duration of breast-feeding is concerned, the situation in of Sao Paulo is comparable with that in any metropolis in industrialized countries (12). An increase in the average duration of exclusive breast-feeding to 82.8 days in a district of Sao Paulo has recently been reported by other workers who used the same statistical approach that we employed.b Other projects carried out in Sao Paulo had already highlighted this probable impact of the national campaign (13). It should be noted that of the 90 children born during the first phase of the campaign (March 1981 to July 1982), less than 19% were breast-fed for more than 6 months. These were precisely those infants whose mothers were exposed to the initial advertise- Infant and young child nutrition 1. Progress and evaluation report and status of implementation of the International Code of Marketing of Breast-milk Substitutes. Report represented at the 39th World Health Assembly, May 1986. Document WHA 39/1986/ REC/1. b Monteiro, C.A. et al. [Mother and child studies in Ersa-Man- daqui: feeding practices, morbidity and use of health services]. Department of Nutrition (FSPUSP) Division of Maternal and Child Health, Instituto de Saude (SES), Sao Paulo, Brazil. Unpublished report to Pan American Health Organization, May 1988 (in Por- tuguese). WHO Bulletin OMS. Vol. 68 1990. 369 M.F. Rea & E.S. Berquo ments in the mass media that promoted breast-feed- ing. The advertisements, which were broadcast on radio and television through a small number of short commercials for a period of 45 days, were designed to communicate the advantages of breast milk, includ- ing the protection it offers against disease and that "weak" milk does not exist; furthermore, they tried to dispel some commonly held taboos, about breast- feeding. The main slogan was "Breast-feed for at least the first 6 months". The mothers of children born during and follow- ing the first campaign were not affected by the message, mainly because the 45-day broadcast period was not repeated. During this phase, manufacturers of breast-milk substitutes continued to advertise their products in the mass media. In addition, advertise- ments on the labels of artificial milk products in supermarkets claimed that the milk was "mater- nalized". Also, health services encouraged the use of powdered milk through food supplement program- mes promoted by the Sao Paulo State Government, and health workers stimulated mothers to use artifical milk. The approval by the World Health Assembly of the International Code of Marketing of Breast-milk Substitutes in May 1981 had no effect in Brazil during this phase.c Only in 1982, under inter- national pressure, did the largest manufacturer of infant foods in Brazil begin to obey the code. In the second phase of the campaign (August 1982 to December 1983), the proportion of children who were breast-fed for more than 6 months increased to 34.4%, i.e., one in every three mothers had at last been reached by the message: "Breast- feeding: 6 months that are worth a life". The mes- sages were delivered by national celebrities and the campaign continued for longer than in the first phase, albeit with some interruptions. The second phase also saw stricter controls on advertising by infant food manufacturers, although these were far from suf- ficient. The managers of the programme during this phase were aware of the need for surveillance against unethical advertising and attempted to restrain it by complaining to the mass media whenever such adver- tisements were shown. Also, the first draft of a Brazilian Code of Marketing of Breast-milk Sub- stitutes, based on the International Code, was drawn up. During the third phase (January to December 1984), when the actions undertaken as part of the programme began to have a nationwide scope, UNICEF supported a number of seminars to train I Resolution WHA34.22. Handbook of Resolutions and Decisions of the World Health Assembly and the Executive Board, Volume 11, 1973-1984. Geneva, World Health Organization, 1985, pp. 91-92. health personnel in Sao Paulo. Mother's groups were founded, "breast-feeding" was given better coverage in the curricula in medical schools, and rooming-in was implemented. Meanwhile, professional associa- tions disseminated the benefits of breast-feeding in several ways, both to their members and to the general public, while the mass media campaign became non-systematic and spontaneous: for exam- ple, a group of doctors launched their own breast- feeding promotion campaign on television without any links with the coordinators of the national programme. In the course of this phase the propor- tion of children who were breast-fed for more than 6 months increased only slightly to about 38%, and then dropped back to 27.6% during the final phase. During this following phase (January 1985 to Decem- ber 1986) the programme was characterized by lack of nationwide coordination and by a failure to encourage or invest in the promotion of breast-feed- ing-an activity that should be given as much priority as the other officially designated basic health actions (vaccination, growth monitoring, and control of diarrhoea). The state governments, including that of Sao Paulo, were still undertaking breast-feeding activities, but the intensity of these measures was far less than it had been during the previous phases. There is no way of determining whether this downturn in activity reflected the winding down of the programme or a lack of enthusiasm about breast- feeding in the Ministry of Health and the responsible state government agencies. There may be other fac- tors that caused the phenomenon. Did, for example, the 87 children born in 1985-86, who had an index child as a sibling, have the same chance of being breast-fed for a long time, or did gestation of the index child interrupt the breast-feeding process? Such a question is justified because the results for index children (those born between May 1986 and May 1987) showed that the duration of breast-feeding continued to rise in Sao Paulo. In any case, there is no doubt that the Brazilian national breast-feeding programme contributed to revert the harmful decline in breast-feeding practices that occurred in the coun- try in the 1970s. Aclknowledgements We thank the Financiadora de Estudos e Projetos (FINEP), the Science and Technology Secretariat of the Ministry of Health, and the Instituto de Alimentacao e NutriQ&o (INAN) for funding this study. The United Nations Children's Fund (UNICEF) is thanked for funding the evaluation conducted before the breast-feeding pro- gramme began in 1981. 370 WHO Bulletin OMS. Vol. 68 1990. Impact of the Brazilian national breast-feeding programme In Greater Sao Paulo Resume Impact du programme national brhslllen d'allaltement au sein sur les habitudes des m6res de Sio Paulo en matlere d'allaltement En 1981, le Bresil a lanc6 un vaste programme national d'alimentation au sein qui avait Mt prkc6d6 par une 6valuation des habitudes en mati6re d'alimentation du nouveau-ne dans deux zones urbaines du pays. Ce programme etait multi- sectoriel et comprenait: la planification et la mise en oeuvre de campagnes par les m6dias; la struc- turation des services de maternit6, prenant l'alimentation au sein comme priorit6; la formation des agents de soins de sant6; la modification des programmes d'6coles de sante; la reglementation du marche des substituts du lait maternel; la sur- veillance de la legislation du travail maternel. Nous decrivons ici les resultats initiaux d'une evaluation faite six ans apres la mise en c6uvre du programme dans la region du Grand Sao Paulo. La m6thodologie utilis6e 6tait analogue a celle employ6e en 1981 avant le d6but du programme, et consistait en un interrogatoire, a la fois de m6decins et d'un echantillon representatif de m6res qui consultaient des services de soins infantiles ouverts a tous les groupes sociaux, quels que soient leurs revenus. Au total, 300 meres ayant des enfants Ag6s de 0 a 8 mois ont ete interrog6es en 1981 et 497 meres ayant des enfants de 0 a 12 mois l'ont WtE en 1987. Les meres 6taient 6gale- ment interrog6es sur la dur6e de l'allaitement au sein de tous leurs enfants nes depuis 1981. Les r6sultats montrent que le programme a eu comme resultat une augmentation du nombre de femmes qui ont commenc6 c allaiter de 91,3% a 94,7% et une augmentation de la prevalence de I'allaitement au sein de 41,2% A 63,0%; ces dif- f6rences sont statistiquement significatives (P< 0,005). La proportion des enfants precedents qui avaient te nourris au sein pendant plus de six mois est pass6e de 18,9% pour ceux n6s en 1981-1982 a 37,7% pour ceux n6s en 1984 et a diminue a nouveau jusqu'a 27,6% en 1985-1986. L'article conclut que le programme a un impact reel sur l'alimentation au sein des enfants actuels et que cet impact tendait c 6tre maximal au moment ou' les activit6s du programme etaient les plus intenses. References 1. Wlnikoff, B. & Boer, E. The obstetrician's opportunity: translating "breast is best" from theory to practice. American journal of obstetrics and gynecology, 138: 105-117 (1980). 2. JoIlift, D.B. & Jellife, E.P. Human milk in the modern world. New York, Oxford University Press, 1979. 3. Winikoff, B. et al. Overcoming obstacles to breast- feeding in a large municipal hospital: applications of lessons learned. Pediatrics, 80: 423-433 (1987). 4. Ross, S.M. et al. Breast-feeding support. South African medical journal, 72: 357-358 (1987). 5. Taylor, P.M. et al. Extra early mother- infant contact and duration of breast-feeding. Acta paediatrica Scandinavica, 316: 15-22 (1985). 6. Blerre, J. & Ekelund, H. Breast-feeding and post- partum care. Acta paediatrica Scandinavica, suppl. 206: 125-126 (1970). 7. Matthal, J. The Brazilian National Breast-feeding Programme. Assignment children, 61/62: 225-247 (1983). 8. Berqu6, E. et al. [Characteristics and determinants of breast-feeding in Greater Sbo Paulo and Greater Recife]. Sao Paulo, Centro Brasileiro de Analise e Planejamento (CEBRAP), 1984 (in Portuguese). 9. Page, H. et al. Illustrative analyses: breast-feeding in Pakistan. Voorburg, Netherlands, International Stat- istical Institute, 1982 (World Fertility Survey Scientific Report No. 37). 10. Amerkan Academy of Pediatrics. Report of the Task Force on the Assessment of Scientific Evidence Relating to Infant Feeding Practices and Infant Health. Pediatrics, 74 (4, part 2, suppl.) (1984). 11. Cochran, W.G. Some methods for strengthening the common x2 test. Biometrics, 10: 417-451 (1954). 12. Montelro, C.A. et al. [State of health of children in the municipality of Sao Paulo, 1984-85. III. Breast-feed- ing]. Revista de saLde publica, 21: 13-22 (1987) (in Portuguese). 13. Montelro, C.A. et al. The recent revival of breast- feeding in the city of Sao Paulo, Brazil. Americanjournal of public health, 77: 964-966 (1987). WHO Bulletin OMS. Vol. 68 1990. 371