sntm
10-09-2003, 11:25 AM
(browsing instead of working on my article!)
Pediatric Clinics of North America
Volume 48 • Number 1 • February 2001
Copyright © 2001 W. B. Saunders Company
THE EVIDENCE FOR BREASTFEEDING
--------------------------------------------------------------------------------
Breastfeeding Beyond 12 Months
An Historical Perspective
Yvette Piovanetti MD
--------------------------------------------------------------------------------
Proyecto Lacta, Centro Pediatrico de Lactancia y Crianza, San Juan, Puerto Rico
--------------------------------------------------------------------------------
Address reprint requests to
Yvette Piovanetti, MD
400 Domenech, Suite 413
Hato Rey, PR 00918
e-mail: [email protected]
Breastfeeding practice in the United States should parallel the recommendations of the American Academy of Pediatrics (AAP),[1] in which breastfeeding is recommended for at least the first 12 months of life. At the same time, the World Health Organization and UNICEF[6] state that breastfeeding should be continued for the first 2 years of life. The contrast between these recommendations is of interest. As such, pediatricians must assume an objective approach when offering advice about weaning and not allow their cultural biases or prejudices to interfere with the practice of extended breastfeeding. Breastfeeding should be encouraged into the second year for numerous reasons. The age of weaning in the twenty-first century should extend beyond 12 months ( Tables 1 and 2 ).
TABLE 1 -- HISTORICAL REASONS WHY BREASTFEEDING SHOULD BE MORE THAN 12 MONTHS IN DURATION Civilization Breastfeeding Duration (y) Source
Mesopotamia, Babylon c. 1000 BC 2 Sumerian script with wet-nursing contracts
Hebrew (ancient) c. 536 BC 3 Talmud
Indian c. 576 BC 2 minimum Ayurveda
Greco-Roman 2-3 Galen, Soranus
Islam 2 Koran
16th-century Europe 2 Poem "La Balia Wet Nurse" by Luigi Tansillo
Colonial America 1 Popular periodicals
TABLE 2 -- HISTORICAL IDEAS ON THE APPROPRIATE DURATION OF BREASTFEEDING Source Rationale Duration
Aristotle 384-322 BC Until onset of menses 12-18 months
Soranus 98-138 AD Teeth eruption 2-3 y
Galen 130-200 AD Book De Sanita Tuenda 3 y
Oribasius 325-403 AD Book 5 Up to age 6 y
Anthropologic theories Until infant mammals acquire independence Infant acquires 4 × birth weight; 1/3 adult weight; 6 × length of gestation; eruption of first molar
Zulu society Until new pregnancy 12-18 mo
Even in recent years, pediatricians have not recommended extended breastfeeding. A survey of 1602 members of the AAP reported that, of those responding, only 37% recommended breastfeeding for 1 year.[27] Most pediatricians were unfamiliar or did not respond to the AAP recommendations. With respect to the duration of breastfeeding, just as medical education has been lagging behind in breastfeeding education (especially in management issues[12] ), so has the advice offered by pediatricians to their patients regarding weaning recommendations. In an AAP survey of self-selected medical practitioners who wished to improve their office-based breastfeeding efforts, fully 25% of participants discouraged breastfeeding after 2 years and stated that weaning was the mother's decision.[2] Meanwhile, the National Health Objectives for Breastfeeding as outlined in the Healthy People 2000 program have been modified for 2010.[15] For the first time, the new recommendations include a goal of 25% breastfeeding children at 12 months of age.
This article discusses the historical, scientific, and medical issues behind breastfeeding after the first 12 months of life.
HISTORICAL OVERVIEW
Patterns of duration of breastfeeding were longer in ancient times.[17] Eastern and Western civilizations thrived with longer breastfeeding patterns. Among ancient Hebrews, total weaning took place at approximately age 3 years. A breastfeeding duration for at least 2 years is specified in such sources as the Talmud, the Koran, medical texts from India, and wet-nursing contracts found in Babylonia. Greek writings from Aristotle later suggested that women should breastfeed while no menstruation was occurring, typically between child ages of 1 and 2 years. The Spartans were quoted as advocating restrictive feedings. Scientific writings from two Roman physicians, Soranus and Galen, ruled infant feeding patterns until the eighteenth century. Soranus first suggested that infants should breastfeed until their complete set of teeth have erupted, whereas Galen recommended breastfeeding until the age of 3. Roman civilizations highly valued breastfeeding, as evidenced in their respect and representation of their breastfeeding goddesses and myths; however, the remains of Roman children and adults with rickets suggests that Roman women cut short their breastfeeding experience.
Human milk also was recognized for its therapeutic qualities beyond infant nutrition; it was considered beneficial for eye problems by the Chinese, Indian, Egyptians, Romans, and Samoans. An artistic rendition of this added value of human milk is seen in the painting by Cagnacci, Roman Charity (Fig. 1) (Figure Not Available) . Pero breastfeeds her father Cimon when she visits him at his prison cell. He thrives despite having been sentenced to death by starvation for charges of treason. The legend then states that the Emperor was so moved that he pardoned Cimon.
Figure 1. (Figure Not Available) Roman Charity. (Courtesy of The Museo de Arte de Ponce, The Luis A. Ferre Foundation, Inc., Ponce, Puerto Rico.)
With progressive introduction of early mixed feedings, the medical community contributed to early weaning patterns in Western civilizations. Leading medical writers of the eighteenth century had written extensively on nursing and the management of children from birth to 3 years of age. Among them was the British physician Cadogan (1711-1797), from Bristol Founding Hospital, who advocated against early introduction of solid foods and censuring feeding customs that interfere with successful breastfeeding practices. He criticized the practice of separating mothers from their infants to be sent to wet nurses because he contended that these children would suffer from lack of bonding and the benefits of their mothers' milk.[7] Smith, another London physician (1736-1789), was the first to recommend breastfeeding solely for the first 6 months. Wet nursing was not common in the United States, and the requirements for a wet nurse were at times frivolous (e.g., hair color).[3] Curiously, in these discourses, writers also included some of the contraindications for wet nurses; they excluded drug addicts and those who had evidence of smallpox infection, and suggested that wet nurses should have "good nipples."
Breastfeeding for 1 year was common in colonial America, an observation consistent with the birth-interval pattern of families. Shortened breastfeeding patterns alarmed several physicians in the nineteenth century while medicine was adopting a more scientific approach. Improper feeding technique was the primary cause of infant mortality in the nineteenth century and was one of the main reasons for the origins of pediatrics as a specialty in medicine. The weaning advice from one noted physician in 1895, Holt, included that it begin at 9 or 10 months of age, substituting one feeding a day until full weaning. Smith (1881) suggested that weaning begin at 10 to 12 months of age or until canine teeth appeared (but never in summer or warm weather). This recommendation of not weaning in summer because of fear of diarrhea was shared by prominent pediatricians, such as Koplik (1858-1927) and Grffith.[8]
Nutritional deficiencies with increased morbidity (e.g., scurvy and rickets) appeared as breastfeeding diminished. Data from the US census of 1900-1910 revealed that children who were breastfed had a 40% lower mortality rate than did their formula-fed peers. Modern medicine adopted calorimetric methods for infant feeding and the concepts of bacteriology to help advance a "clean milk campaign" that favored the advocacy of formula feeding. By 1950, pediatricians recommended the introduction of vegetables to the diet at age 4 months. Thus, the advent of commercial interests and the modern professional advice led to the decrease in the rate of breastfeeding in the twentieth century.
Evidence for prolonged breastfeeding patterns already exists in the anthropologic literature. For traditional societies worldwide, the age of weaning ranges between 2 and 4 years of age. Different theories prevail. As primates, mammals have longer periods of maternal dependence and longer life spans. Stuart-Macadams and Dettwyler[10] postulate in A Time to Wean that weaning should occur at the time the infant acquires four times his or her birth weight (2-3 y in the United States and 3-4 y for a marginally nourished population). Other suggestions for weaning are when the infant reaches one third of proposed adult weight (4-7 y, which means that boys would nurse longer), according to a multiple of a length of the gestation, or according to time of eruption of first molar tooth (genetically controlled between 5 and 6 y in humans). This timing of the eruption of the first molar curiously seems to coincide with the age of full maturation of the immune system. So complete weaning from the breast seen from this anthropologic standpoint is a variable process taking into account the individual development of each child or readiness as genetically determined.
EFFECTS ON INFANT HEALTH
Breastfeeding protects against infections and allergies, especially in infancy and the newborn period. These and other health benefits are discussed in detail elsewhere in this issue. The evidence for increased health benefits with extended breastfeeding is mounting. Reports suggest that prolonged protection against specific infections occurs with prolonged breastfeeding. Infection with Haemophilus influenzae type B reportedly is more likely in bottle-fed infants, with consistent evidence of protection of young children from chronic otitis media with prolonged breastfeeding.[13] Additional evidence of continued protective effect is that the concentrations of immunologic factors in human milk are relatively stable during the second year of breastfeeding.[13]
With respect to chronic disease in pediatrics, several reports show protective effects of breastfeeding. One report by Shu et al[29] indicates that breastfeeding decreases the risk for childhood leukemia; the longer the duration of breastfeeding, the stronger the association. Similarly, other reviews[9] [22] indicate that the protective effect of breastfeeding on lymphoma is present in infants with longer duration of breastfeeding.
Improved cognitive outcomes for the breastfed infants have been reported by different investigators.[16] The effects also are pervasive extending into academic achievements. Some authors argue the possibility that genetic and socioenvironmental factors[19] have a major role, but in a meta-analysis by Anderson et al,[3] higher levels of cognitive achievement were observed at all ages, with a clear correlation observed in major benefits with increased duration of breastfeeding.
EFFECTS ON INFANT GROWTH
Various studies in developing countries have suggested a relationship between prolonged breastfeeding and malnutrition, but an extensive review[14] failed to confirm any positive association. Linear growth in breastfed infants also has been shown to differ from that of formula-fed infants. Breastfeeding longer than 12 months in Denmark affected negatively linear growth in infancy (1 cm shorter) but no difference in adult height.[24] In a study in Peru,[21] breastfeeding children aged 12 to 24 months showed different growth patterns depending on the dietary intake and the prevalence of diarrhea. From this complex observation, the investigators concluded that breastfeeding should be extended beyond 12 months, especially in those children who have low dietary intakes and high diarrheal morbidity. In this latter subgroup, breastfed infants had increased linear growth. Children who also benefit more from extended breastfeeding in Senegal are those not thriving and have poor hygiene and living conditions.[30] Growth patterns, linear velocity, and height for age were greater among the poorer children. Growth patterns also were affected by breastfeeding.
EFFECTS ON SOCIETY
Until recently, mothers who practiced extended breastfeeding, such as those who belong to La Leche League International (LLI), have learned to protect themselves from the censure of society.[4] Experts have advocated repression while mothers also should enjoy breastfeeding as an experience that boosts self-esteem. Elizabeth Baldwin, a legal adviser to LLI, stated that, in some cases, it is better not to openly admit to social case workers whether you still treasure extended breastfeeding because of the small risk for being wrongly accused of abuse, as in past cases of divorce settlement in which false reports were filed. Some self-help books have been published to assist mothers in preparation for weaning.[5]
SUMMARY
A decade ago, child psychiatrist Coello-Novello,[17] in her term as Surgeon General of the United States, said, "It's the lucky baby, I feel, who continues to nurse until he's two." The accumulated evidence supports her statement. The understanding of the benefits of breastfeeding beyond 12 months should support the cultural change in which eventually prolonged breastfeeding becomes normal.
References
1. American Academy of Pediatrics: Breastfeeding and the use of human milk. Pediatrics 100:1035-1039, 1997 Full Text
2. American Academy of Pediatrics: Summary Report ACQUIP Exercise 3: Breastfeeding Promotion and the Healthy Newborn Infant #14 Jan 2000
3. Anderson J, Johnstone B, Remley D: Breast-feeding and cognitive development: A meta-analysis. Am J Clin Nutr 70:525-535, 1999 Abstract
4. Baumslag N, Michels D: Milk Money and Madness: The Culture and Politics of Breastfeeding. Westport, CT, Bergin and Garvey, 1995
5. Blum LM: At The Breast. Boston, Beacon Press, 1999
6. Breastfeeding: Foundation for a Healthy Future. New York, UNICEF, August 1999
7. Colon AR: Nurturing Children: A History of Pediatrics. Greenwood Press, 1999
8. Cone T: Treatise on Infant Feeding in Nineteenth Century America. Ross Labs, 1954, p 17-37
9. Davis MK: Review of the Evidence for an association between infant feeding and childhood cancer. International Journal of Cancer II:29-33, 1998
10. Stuart-Macadams P, Dettwyler K: A time to wean. In Breastfeeding: Biocultural Perspectives (Foundations of Human Behavior). New York, Aldine De Guyer, 1995, pp 39-73
11. Enger SM, Ross RK, Henderson B, et al: Breastfeeding history: Pregnancy experience and risk of breast cancer. Int J Epidemiol 28:396-402, 1999 Abstract
12. Freed GL, Clark SJ, Sorenson JR, et al: National assessment of physicians' breastfeeding knowledge, attitudes, training and experience. JAMA 273:472-476, 1995 Abstract
13. Goldman AS: Immunologic components in human milk during the second year of lactation. Acta Paediatr Scand 72:461-462, 1983 Citation
14. Grummer-Strawn LM: Does prolonged breast-feeding impair child growth? A critical review. Pediatrics 91:766-771, 1993 Abstract
15. Healthy People 2010: Objectives: Maternal, Infant, and Child Health. Available: http://www.health.gov/healthypeople/Document/HTML/Volume2/16MICH. 36-37
16. Horwood LJ, Fergusson DM: Breastfeeding and later cognitive and academic outcomes. Pediatrics 101:e9, 1998 Abstract
17. Huggins K, Ziedrich, L: The Nursing Mother's Guide to Weaning. Boston, Harvard Common Press, 1994
18. Institute of Medicine: Nutrition during Lactation. Washington, National Academy Press, 1991
19. Jacobson SW, Chiodo LM, Jacobson JL: Breastfeeding effects on intelligence quotients in 4 and 11-year-old children. Pediatrics 103:e7, 1999 Abstract
20. Jakobsen MS, Sodemann M, Molbak K, et al: Reason for termination of breastfeeding and the length of breastfeeding. Int J Epidemiol 25:115-121, 1996 Abstract
21. Marquis GS: Breastfeeding and stunting among toddlers in Peru [abstract 013]. In Programs and Abstracts of the 9th International Conference of the International Society for Research in Human Milk and Lactation. Munich, Germany, Kloster Irsee, October, 1999
22. Mathur GP, Gupta N, Mathur S, et al: Breastfeeding and childhood cancer. Indian Pediatr 30:651-657, 1993 Abstract
23. McCrory MA, Nummsen-Rivers LA, Mole PA, et al: Randomized trial of the short-term effects of dieting compared with dieting plus aerobic exercise on lactation performance. Am J Clin Nutr 69:959-967, 1999 Abstract
24. Michaelsen KF, Mortensen El, Reinish JM: Duration of breastfeeding and linear growth [abstract 015]. In Programs and Abstracts of the 9th International Conference of the International Society for Research in Human Milk and Lactation. Munich, Germany, Kloster Irsee, October, 1999
25. National Breastfeeding Policy Conference, UCLA Center for Healthier Children: Families and Communities Breastfeeding Resource Program. Washington, DC, Health Resources Services Administration, 1998
26. Rosenblatt KA, Thomas DB: Prolonged lactation and endometrial cancer. WHO Collaborative Study of Neoplasia and Steroid Contraceptives. Int J Epidemiol 24:499-503, 1995 Abstract
27. Schanler RJ, O'Connor KG, Lawrence RA: Pediatricians' practices and attitudes regarding breastfeeding promotion. Pediatrics 103:e35, 1999 Abstract
28. Scott JA, Binns CW: Factors associated with the initiation and duration of breastfeeding: A review of the literature. Breastfeeding Review 7:5-16, 1999
29. Shu KO, Linet MS, Steinbuch M, et al: Breastfeeding and risk of childhood acute leukemia. J Natl Cancer Inst 20:1765-1772, 1999 Abstract
30. Simondon KB, Simondon F, Costes A, et al: Breastfeeding and growth in rural Senegalese toddlers [abstract 014]. In Programs and Abstracts of the 9th International Conference of the International Society for Research in Human Milk and Lactation. Munich, Germany, Kloster Irsee, October, 1999
31. Sugarman M, Kendall-Tackett KA: Weaning ages in a sample of American women who practice extended breastfeeding. Clin Pediatr 3:642-647, 1995 Abstract
32. Thomas DB, Noonan EA: Breast cancer and prolonged lactation. WHO Collaborative Study of Neoplasia and Steroid Contraceptives. Int J Epidemiol 24:499-503, 1995 Abstract
33. Villalpando S, Hamosh M: Early and late effects of breastfeeding: Does breastfeeding really matter? Biol Neonate 74:177-191, 1998 Abstract
34. von Kries R, Koletzko B, Sauerwald T, et al: Breastfeeding and obesity: Cross sectional study. BMJ 319:147-150, 1999 Abstract
35. Winkvist A, Rasmussen KM: Impact of lactation on maternal body weight and composition. J Mammary Gland Biol Neoplasia 4:309-318, 1999 Abstract
shannon
not-even-pregnant-yet-overachiever
trying-to-conceive :)
PREGNANT! EDD 6/9/03
mama to Jack 6/6/03
Pediatric Clinics of North America
Volume 48 • Number 1 • February 2001
Copyright © 2001 W. B. Saunders Company
THE EVIDENCE FOR BREASTFEEDING
--------------------------------------------------------------------------------
Breastfeeding Beyond 12 Months
An Historical Perspective
Yvette Piovanetti MD
--------------------------------------------------------------------------------
Proyecto Lacta, Centro Pediatrico de Lactancia y Crianza, San Juan, Puerto Rico
--------------------------------------------------------------------------------
Address reprint requests to
Yvette Piovanetti, MD
400 Domenech, Suite 413
Hato Rey, PR 00918
e-mail: [email protected]
Breastfeeding practice in the United States should parallel the recommendations of the American Academy of Pediatrics (AAP),[1] in which breastfeeding is recommended for at least the first 12 months of life. At the same time, the World Health Organization and UNICEF[6] state that breastfeeding should be continued for the first 2 years of life. The contrast between these recommendations is of interest. As such, pediatricians must assume an objective approach when offering advice about weaning and not allow their cultural biases or prejudices to interfere with the practice of extended breastfeeding. Breastfeeding should be encouraged into the second year for numerous reasons. The age of weaning in the twenty-first century should extend beyond 12 months ( Tables 1 and 2 ).
TABLE 1 -- HISTORICAL REASONS WHY BREASTFEEDING SHOULD BE MORE THAN 12 MONTHS IN DURATION Civilization Breastfeeding Duration (y) Source
Mesopotamia, Babylon c. 1000 BC 2 Sumerian script with wet-nursing contracts
Hebrew (ancient) c. 536 BC 3 Talmud
Indian c. 576 BC 2 minimum Ayurveda
Greco-Roman 2-3 Galen, Soranus
Islam 2 Koran
16th-century Europe 2 Poem "La Balia Wet Nurse" by Luigi Tansillo
Colonial America 1 Popular periodicals
TABLE 2 -- HISTORICAL IDEAS ON THE APPROPRIATE DURATION OF BREASTFEEDING Source Rationale Duration
Aristotle 384-322 BC Until onset of menses 12-18 months
Soranus 98-138 AD Teeth eruption 2-3 y
Galen 130-200 AD Book De Sanita Tuenda 3 y
Oribasius 325-403 AD Book 5 Up to age 6 y
Anthropologic theories Until infant mammals acquire independence Infant acquires 4 × birth weight; 1/3 adult weight; 6 × length of gestation; eruption of first molar
Zulu society Until new pregnancy 12-18 mo
Even in recent years, pediatricians have not recommended extended breastfeeding. A survey of 1602 members of the AAP reported that, of those responding, only 37% recommended breastfeeding for 1 year.[27] Most pediatricians were unfamiliar or did not respond to the AAP recommendations. With respect to the duration of breastfeeding, just as medical education has been lagging behind in breastfeeding education (especially in management issues[12] ), so has the advice offered by pediatricians to their patients regarding weaning recommendations. In an AAP survey of self-selected medical practitioners who wished to improve their office-based breastfeeding efforts, fully 25% of participants discouraged breastfeeding after 2 years and stated that weaning was the mother's decision.[2] Meanwhile, the National Health Objectives for Breastfeeding as outlined in the Healthy People 2000 program have been modified for 2010.[15] For the first time, the new recommendations include a goal of 25% breastfeeding children at 12 months of age.
This article discusses the historical, scientific, and medical issues behind breastfeeding after the first 12 months of life.
HISTORICAL OVERVIEW
Patterns of duration of breastfeeding were longer in ancient times.[17] Eastern and Western civilizations thrived with longer breastfeeding patterns. Among ancient Hebrews, total weaning took place at approximately age 3 years. A breastfeeding duration for at least 2 years is specified in such sources as the Talmud, the Koran, medical texts from India, and wet-nursing contracts found in Babylonia. Greek writings from Aristotle later suggested that women should breastfeed while no menstruation was occurring, typically between child ages of 1 and 2 years. The Spartans were quoted as advocating restrictive feedings. Scientific writings from two Roman physicians, Soranus and Galen, ruled infant feeding patterns until the eighteenth century. Soranus first suggested that infants should breastfeed until their complete set of teeth have erupted, whereas Galen recommended breastfeeding until the age of 3. Roman civilizations highly valued breastfeeding, as evidenced in their respect and representation of their breastfeeding goddesses and myths; however, the remains of Roman children and adults with rickets suggests that Roman women cut short their breastfeeding experience.
Human milk also was recognized for its therapeutic qualities beyond infant nutrition; it was considered beneficial for eye problems by the Chinese, Indian, Egyptians, Romans, and Samoans. An artistic rendition of this added value of human milk is seen in the painting by Cagnacci, Roman Charity (Fig. 1) (Figure Not Available) . Pero breastfeeds her father Cimon when she visits him at his prison cell. He thrives despite having been sentenced to death by starvation for charges of treason. The legend then states that the Emperor was so moved that he pardoned Cimon.
Figure 1. (Figure Not Available) Roman Charity. (Courtesy of The Museo de Arte de Ponce, The Luis A. Ferre Foundation, Inc., Ponce, Puerto Rico.)
With progressive introduction of early mixed feedings, the medical community contributed to early weaning patterns in Western civilizations. Leading medical writers of the eighteenth century had written extensively on nursing and the management of children from birth to 3 years of age. Among them was the British physician Cadogan (1711-1797), from Bristol Founding Hospital, who advocated against early introduction of solid foods and censuring feeding customs that interfere with successful breastfeeding practices. He criticized the practice of separating mothers from their infants to be sent to wet nurses because he contended that these children would suffer from lack of bonding and the benefits of their mothers' milk.[7] Smith, another London physician (1736-1789), was the first to recommend breastfeeding solely for the first 6 months. Wet nursing was not common in the United States, and the requirements for a wet nurse were at times frivolous (e.g., hair color).[3] Curiously, in these discourses, writers also included some of the contraindications for wet nurses; they excluded drug addicts and those who had evidence of smallpox infection, and suggested that wet nurses should have "good nipples."
Breastfeeding for 1 year was common in colonial America, an observation consistent with the birth-interval pattern of families. Shortened breastfeeding patterns alarmed several physicians in the nineteenth century while medicine was adopting a more scientific approach. Improper feeding technique was the primary cause of infant mortality in the nineteenth century and was one of the main reasons for the origins of pediatrics as a specialty in medicine. The weaning advice from one noted physician in 1895, Holt, included that it begin at 9 or 10 months of age, substituting one feeding a day until full weaning. Smith (1881) suggested that weaning begin at 10 to 12 months of age or until canine teeth appeared (but never in summer or warm weather). This recommendation of not weaning in summer because of fear of diarrhea was shared by prominent pediatricians, such as Koplik (1858-1927) and Grffith.[8]
Nutritional deficiencies with increased morbidity (e.g., scurvy and rickets) appeared as breastfeeding diminished. Data from the US census of 1900-1910 revealed that children who were breastfed had a 40% lower mortality rate than did their formula-fed peers. Modern medicine adopted calorimetric methods for infant feeding and the concepts of bacteriology to help advance a "clean milk campaign" that favored the advocacy of formula feeding. By 1950, pediatricians recommended the introduction of vegetables to the diet at age 4 months. Thus, the advent of commercial interests and the modern professional advice led to the decrease in the rate of breastfeeding in the twentieth century.
Evidence for prolonged breastfeeding patterns already exists in the anthropologic literature. For traditional societies worldwide, the age of weaning ranges between 2 and 4 years of age. Different theories prevail. As primates, mammals have longer periods of maternal dependence and longer life spans. Stuart-Macadams and Dettwyler[10] postulate in A Time to Wean that weaning should occur at the time the infant acquires four times his or her birth weight (2-3 y in the United States and 3-4 y for a marginally nourished population). Other suggestions for weaning are when the infant reaches one third of proposed adult weight (4-7 y, which means that boys would nurse longer), according to a multiple of a length of the gestation, or according to time of eruption of first molar tooth (genetically controlled between 5 and 6 y in humans). This timing of the eruption of the first molar curiously seems to coincide with the age of full maturation of the immune system. So complete weaning from the breast seen from this anthropologic standpoint is a variable process taking into account the individual development of each child or readiness as genetically determined.
EFFECTS ON INFANT HEALTH
Breastfeeding protects against infections and allergies, especially in infancy and the newborn period. These and other health benefits are discussed in detail elsewhere in this issue. The evidence for increased health benefits with extended breastfeeding is mounting. Reports suggest that prolonged protection against specific infections occurs with prolonged breastfeeding. Infection with Haemophilus influenzae type B reportedly is more likely in bottle-fed infants, with consistent evidence of protection of young children from chronic otitis media with prolonged breastfeeding.[13] Additional evidence of continued protective effect is that the concentrations of immunologic factors in human milk are relatively stable during the second year of breastfeeding.[13]
With respect to chronic disease in pediatrics, several reports show protective effects of breastfeeding. One report by Shu et al[29] indicates that breastfeeding decreases the risk for childhood leukemia; the longer the duration of breastfeeding, the stronger the association. Similarly, other reviews[9] [22] indicate that the protective effect of breastfeeding on lymphoma is present in infants with longer duration of breastfeeding.
Improved cognitive outcomes for the breastfed infants have been reported by different investigators.[16] The effects also are pervasive extending into academic achievements. Some authors argue the possibility that genetic and socioenvironmental factors[19] have a major role, but in a meta-analysis by Anderson et al,[3] higher levels of cognitive achievement were observed at all ages, with a clear correlation observed in major benefits with increased duration of breastfeeding.
EFFECTS ON INFANT GROWTH
Various studies in developing countries have suggested a relationship between prolonged breastfeeding and malnutrition, but an extensive review[14] failed to confirm any positive association. Linear growth in breastfed infants also has been shown to differ from that of formula-fed infants. Breastfeeding longer than 12 months in Denmark affected negatively linear growth in infancy (1 cm shorter) but no difference in adult height.[24] In a study in Peru,[21] breastfeeding children aged 12 to 24 months showed different growth patterns depending on the dietary intake and the prevalence of diarrhea. From this complex observation, the investigators concluded that breastfeeding should be extended beyond 12 months, especially in those children who have low dietary intakes and high diarrheal morbidity. In this latter subgroup, breastfed infants had increased linear growth. Children who also benefit more from extended breastfeeding in Senegal are those not thriving and have poor hygiene and living conditions.[30] Growth patterns, linear velocity, and height for age were greater among the poorer children. Growth patterns also were affected by breastfeeding.
EFFECTS ON SOCIETY
Until recently, mothers who practiced extended breastfeeding, such as those who belong to La Leche League International (LLI), have learned to protect themselves from the censure of society.[4] Experts have advocated repression while mothers also should enjoy breastfeeding as an experience that boosts self-esteem. Elizabeth Baldwin, a legal adviser to LLI, stated that, in some cases, it is better not to openly admit to social case workers whether you still treasure extended breastfeeding because of the small risk for being wrongly accused of abuse, as in past cases of divorce settlement in which false reports were filed. Some self-help books have been published to assist mothers in preparation for weaning.[5]
SUMMARY
A decade ago, child psychiatrist Coello-Novello,[17] in her term as Surgeon General of the United States, said, "It's the lucky baby, I feel, who continues to nurse until he's two." The accumulated evidence supports her statement. The understanding of the benefits of breastfeeding beyond 12 months should support the cultural change in which eventually prolonged breastfeeding becomes normal.
References
1. American Academy of Pediatrics: Breastfeeding and the use of human milk. Pediatrics 100:1035-1039, 1997 Full Text
2. American Academy of Pediatrics: Summary Report ACQUIP Exercise 3: Breastfeeding Promotion and the Healthy Newborn Infant #14 Jan 2000
3. Anderson J, Johnstone B, Remley D: Breast-feeding and cognitive development: A meta-analysis. Am J Clin Nutr 70:525-535, 1999 Abstract
4. Baumslag N, Michels D: Milk Money and Madness: The Culture and Politics of Breastfeeding. Westport, CT, Bergin and Garvey, 1995
5. Blum LM: At The Breast. Boston, Beacon Press, 1999
6. Breastfeeding: Foundation for a Healthy Future. New York, UNICEF, August 1999
7. Colon AR: Nurturing Children: A History of Pediatrics. Greenwood Press, 1999
8. Cone T: Treatise on Infant Feeding in Nineteenth Century America. Ross Labs, 1954, p 17-37
9. Davis MK: Review of the Evidence for an association between infant feeding and childhood cancer. International Journal of Cancer II:29-33, 1998
10. Stuart-Macadams P, Dettwyler K: A time to wean. In Breastfeeding: Biocultural Perspectives (Foundations of Human Behavior). New York, Aldine De Guyer, 1995, pp 39-73
11. Enger SM, Ross RK, Henderson B, et al: Breastfeeding history: Pregnancy experience and risk of breast cancer. Int J Epidemiol 28:396-402, 1999 Abstract
12. Freed GL, Clark SJ, Sorenson JR, et al: National assessment of physicians' breastfeeding knowledge, attitudes, training and experience. JAMA 273:472-476, 1995 Abstract
13. Goldman AS: Immunologic components in human milk during the second year of lactation. Acta Paediatr Scand 72:461-462, 1983 Citation
14. Grummer-Strawn LM: Does prolonged breast-feeding impair child growth? A critical review. Pediatrics 91:766-771, 1993 Abstract
15. Healthy People 2010: Objectives: Maternal, Infant, and Child Health. Available: http://www.health.gov/healthypeople/Document/HTML/Volume2/16MICH. 36-37
16. Horwood LJ, Fergusson DM: Breastfeeding and later cognitive and academic outcomes. Pediatrics 101:e9, 1998 Abstract
17. Huggins K, Ziedrich, L: The Nursing Mother's Guide to Weaning. Boston, Harvard Common Press, 1994
18. Institute of Medicine: Nutrition during Lactation. Washington, National Academy Press, 1991
19. Jacobson SW, Chiodo LM, Jacobson JL: Breastfeeding effects on intelligence quotients in 4 and 11-year-old children. Pediatrics 103:e7, 1999 Abstract
20. Jakobsen MS, Sodemann M, Molbak K, et al: Reason for termination of breastfeeding and the length of breastfeeding. Int J Epidemiol 25:115-121, 1996 Abstract
21. Marquis GS: Breastfeeding and stunting among toddlers in Peru [abstract 013]. In Programs and Abstracts of the 9th International Conference of the International Society for Research in Human Milk and Lactation. Munich, Germany, Kloster Irsee, October, 1999
22. Mathur GP, Gupta N, Mathur S, et al: Breastfeeding and childhood cancer. Indian Pediatr 30:651-657, 1993 Abstract
23. McCrory MA, Nummsen-Rivers LA, Mole PA, et al: Randomized trial of the short-term effects of dieting compared with dieting plus aerobic exercise on lactation performance. Am J Clin Nutr 69:959-967, 1999 Abstract
24. Michaelsen KF, Mortensen El, Reinish JM: Duration of breastfeeding and linear growth [abstract 015]. In Programs and Abstracts of the 9th International Conference of the International Society for Research in Human Milk and Lactation. Munich, Germany, Kloster Irsee, October, 1999
25. National Breastfeeding Policy Conference, UCLA Center for Healthier Children: Families and Communities Breastfeeding Resource Program. Washington, DC, Health Resources Services Administration, 1998
26. Rosenblatt KA, Thomas DB: Prolonged lactation and endometrial cancer. WHO Collaborative Study of Neoplasia and Steroid Contraceptives. Int J Epidemiol 24:499-503, 1995 Abstract
27. Schanler RJ, O'Connor KG, Lawrence RA: Pediatricians' practices and attitudes regarding breastfeeding promotion. Pediatrics 103:e35, 1999 Abstract
28. Scott JA, Binns CW: Factors associated with the initiation and duration of breastfeeding: A review of the literature. Breastfeeding Review 7:5-16, 1999
29. Shu KO, Linet MS, Steinbuch M, et al: Breastfeeding and risk of childhood acute leukemia. J Natl Cancer Inst 20:1765-1772, 1999 Abstract
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shannon
not-even-pregnant-yet-overachiever
trying-to-conceive :)
PREGNANT! EDD 6/9/03
mama to Jack 6/6/03