[back] Full term
by Kate Mortensen Grad Dip (Counselling), IBCLC,
Reproduced from 'HOT TOPIC'
Number 7 July 2001
Lactation Resource Centre subscribers
The aim of this paper is to briefly look at the current recommendations and
research on breastfeeding duration of one to two years or beyond. All over the
world children were commonly breastfed for two to three years until the
widespread introduction of Western artificial feeding products (Dettwyler 1995).
In the 21st century in Australia mothers find themselves in the position of
having to justify breastfeeding the older child to friends, family, social
workers, legal and health professionals. While the superiority of breastfeeding
is acknowledged, the duration of breastfeeding can still be a contentious issue.
Many of the studies on breastfeeding using relatively short periods of
breastfeeding have found strong evidence that, even in a well-resourced
population, breastfeeding confers many advantages (Brodribb 1997). These
advantages would not be expected to cease at 12 months (Lawrence & Lawrence
1999). The definition of sustained breastfeeding in the literature varies
widely. Some authors consider breastfeeding beyond three months as prolonged,
others six or nine months. This paper examines research that looks at the
breastfed child from around 12 months and beyond, where it is possible to find
Breastfeeding rates in some developed nations
Despite increases in initiation rates beginning in the 1970s, the 1995 National
Health Survey showed that only 46.2% of Australian babies were receiving any
breastmilk at six months of age. At 12 months of age 21.2% of babies are still
being breastfed, this falls to 14.6% after one (1) year (Donath & Amir 2000).
This figure falls far short of the 1994 targets for breastfeeding set by the
Australian Government for the year 2000 for 80% full and partial breastfeeding
at six months. In other developed nations statistics on breastfeeding duration
do not usually measure duration beyond six months. In the UK around 21% of
infants in the 6-12 month age group were being breastfed, while in Norway the
figure is 75% (Hunter 1996). In Italy at approximately 12 months 9.3% were being
breastfed (Faldella et al 1998), in Sweden approximately 45% at nine months (Zetterstrom
1999). In the US 21.6% were breastfeeding at six months (Ryan 1997). From these
statistics it is difficult to say exactly how many babies are being breastfed
beyond 12 months. However in the US and Australia, where the highest rates of
breastfeeding correlate to higher income and older age of mother, this group has
been identified as the group more likely to practice sustained breastfeeding. In
Australia 21.2% still breastfeeding at 12 months represents a substantial number
of mothers and babies (Prentice 1991, Donath & Amir). Sustained breastfeeding
that is continued into the second or third year may be more prevalent than is
commonly thought, because many mothers do not talk about breastfeeding the older
child for fear of negative comments. The term "closet nursing" is used to
describe these mothers by La Leche League members and here in Australia it is
common for mothers to receive critical comments if they are breastfeeding an
older child. (NMAA Newsletter 1999, 2000; Wrigley 1990).
What does the research say about sustained breastfeeding?
Sustained breastfeeding provides valuable nutritional and immunological
benefits (Lawrence & Lawrence 1999). Goldman and Goldblum (1983) showed that
immunologic components of breastmilk are maintained into the second year of
lactation and are still providing protection to the infant. The data showed that
the production of IgA antibodies operates throughout lactation. Gulick found
breastfeeding was inversely associated with episodes of illness in infants. He
found breastfed infants had less episodes of illness as toddlers between the
ages of 16 and 30 months. Human milk continues to provide valuable nutrition and
immuno-protection beyond the baby's first year. Objections to continued nursing
are principally based on custom in addition to a lack of knowledge about the
ongoing value of breastmilk. Lawrence states that while research documents
protection and improved development for at least two years there is also a
positive emotional and bonding experience with long-term nursing. "Thousands of
normal healthy children are breastfed until they are three or four years old" (p
Enhanced cognitive development has been shown to be positively associated
with duration of breastfeeding. Rogan and Gladen (1993) tested children, some of
whom were breastfed up to two years, for IQ and school grades. The results
showed a dose dependent relationship between higher score and duration of
breastfeeding. Horwood et al (2001) studied 214 very low-birthweight children
who were assessed for cognitive ability at seven to eight years. Mothers'
retrospective recall of breastmilk feeding was cross checked with hospital
records and child health record books were also used to aid maternal recall.
Using the revised Wechsler Intelligence Scale the authors found a six point
advantage in verbal IQ for infants who received breastmilk for eight months or
more compared with those who did not receive breastmilk. They also found a clear
and significant dose response relationship even after controlling for
confounding factors. This study points to the growing body of evidence for the
beneficial effect of breastmilk on cognitive development.
Obesity and nutrition
Kries (1999) in a cross-sectional study found a clear, inverse, dose-response
relationship between the duration of breastfeeding and incidence of obesity and
overweight. Longer breastfeeding duration was a significant protective factor,
attributed to the composition of breastmilk rather than other lifestyle factors
which were adjusted for. In a study of affluent United States infants, those who
stopped breastfeeding before 18 months gained more weight from 12 to 24 months,
but were the same in length, in comparison with the infants who breastfed for
longer than 18 months (Dewey et al 1995). Whether or not this higher weight gain
is an advantage is debatable in affluent populations where there is already a
high number of overweight children. In a recent report, type-one diabetes was
linked with higher weight gains during the first year of life (Bruining 2000).
In the isolated situation where inadequate weight gain is a concern, encouraging
greater consumption of good quality complementary foods is advisable rather than
ceasing breastfeeding (WHO 1998).
Another study of mothers who breastfed for 12 months or more showed a more
relaxed attitude to feeding their toddlers and they were less likely to exhibit
high levels of control over when and what their toddlers ate and drank. The
increased intake by toddlers of a variety of foods as well as the fact that
these toddlers were leaner but taller was attributed to the maternal style of
feeding which accompanied longer-term breastfeeding (Fisher et al 2000). The
Toowoomba Children's Nutrition Study (1999) showed that breastfed infants
consumed significantly less full-cream milk, soft drink, cordial and soy drinks
at 12 months of age.
The study by Marangoni et al (2000) showed that concentrations of arachidonic
and docosahexaenoic as well as polyunsaturated fatty acids remain stable in
breastmilk through the period of breastfeeding from one month to 12 months.
Research by Kent et al 1999 also showed that while breastmilk volume declined it
remained a substantial part of the toddlers diet They also showed that milk
production responds to infant demand throughout lactation. 500 ml/day of
breastmilk can provide about one-third of the protein and energy, 45% of vitamin
A, and almost all of the vitamin C that a child needs in the second year of life
Backstrom et al (1999) followed a group of pre-term infants and found that
while mineral supplementation in the short term showed better bone
mineralisation, this advantage was not sustained long term. The greater the
amount of breastmilk infants received, the greater bone mineral acquisition in
the long term. The periods of lactation studied went up to 12 months. (This was
considered a long period of lactation by the authors.) The authors recommend a
long period of breastfeeding to optimise long-term bone mineral acquisition.
Sustained breastfeeding has been assumed by many to be as much a risk factor
for dental caries as formula-feeding, although the research is incomplete and
contradictory. Speller (2000), reviewed the evidence and concluded that, a small
number of breastfed babies are more susceptible to dental decay than others.
However this is due to a number of other risk factors, including excessive
consumption of sugar-rich weaning foods and drinks; family history; fluoride
exposure; mothers health and diet during pregnancy; prematurity and dental
hygiene. Nevertheless bottle-fed babies are significantly more likely to develop
caries. Further research is required into all the risk factors for dental
Breastfeeding promotes mother-child attachment and bonding which in turn may
lead to a greater sense of security for the child (Fergusson & Woodward 1999;
Ainsworth 1973). The emotional benefits of breastfeeding the older child were
emphasised by mothers who cite them as being the most important reasons for
continuing to breastfeed. (Kendall-Tackett & Sugarman 1995; Fergusson & Woodward
1999; Hills-Bonczyk 1994). Breastfeeding is both a biological and a cultural
activity that is modified by a wide variety of beliefs. Beliefs about the nature
of human infancy, the relationship of mother and child, mothers' work
expectations, and ideas about personal independence and autonomy will affect the
breastfeeding relationship (Dettwyler 1995). Reasons for weaning early can
include a mistaken belief that a child will become too dependent and have
difficulty separating from the mother. Ainsworth's (1973) research showed that a
secure attachment to the mother through breastfeeding enabled children to form
attachments to others and to become more independent than a comparable group of
bottle-fed infants. In Fergusson and Woodward's (1999) study those children
breastfed for a longer duration tended to perceive their mothers as more caring
and less over-protective. Mothers in this study who elected to breastfeed were
more likely to come from advantaged socio-economic backgrounds; however, even
after adjusting for these factors, adolescent perceptions of higher maternal
care were significantly associated with duration of breastfeeding.
Effects on the mother
Sustained breastfeeding also provides many benefits to the mother including
lower risk of anaemia, longer periods of lactational amenorrhea, reduced risk of
osteoporosis and breast cancer, promotion of postpartum weight loss and sense of
Research by Sinigaglia et al (1996) found that women with a median lactation
of 22 months were not significantly different in bone mineral density to other
matched groups who had either lactated for a shorter time or not at all. Melton
et al in 1993 studied a random sample of 304 white women in the United States.
showed that breastfeeding beyond eight months was associated with greater bone
mineral density in later life. Reduced risk for osteoporosis has also been found
in other studies with even shorter durations of breastfeeding.
Studies from China and Japan have previously shown a reduced risk for breast
cancer. More recently Zheng et al (2000) showed that prolonged breastfeeding
significantly reduced breast cancer risk, especially for those with a total
lactation duration greater than 72 months. This duration of lactation has not
been studied in Western populations leading the authors to believe that this is
the reason why such a strong protective effect has not been apparent in Western
Mothers find-long term breastfeeding rewarding and natural. They enjoy the
close bond that develops with their child; the main difficulty was being
'strong' in the face of negative reactions. These were the main themes that
emerged from a prospective longitudinal study of 82 primiparas examining
attitudes and reasons for long-term breastfeeding (Hills-Bonyczyket et al 1994).
Around the world
In many countries of the world breastfeeding does continue well into childhood,
two to three years and longer. For example by about two years of age a third or
more of the children in sub-Saharan Africa were still breastfeeding. In five out
of seven Asian countries studied, 50% or more were still being breastfed at two
years; in Bolivia, Peru and Guatemala 40% of children; and in Indonesia 63% of
children are still breastfed at this age (Haggerty & Rutstein 1999). In the
developing nations, sustained breastfeeding is vital to a child's health and
growth (Prentice 1991). At one time extended lactation was considered a risk
factor for malnutrition and growth stunting. However subsequent research has
confirmed that these findings were due in part to reverse causality, as mothers
continued to breastfeed a child who was sick or malnourished, while healthy
strong children tended to be weaned a little earlier (Simonden & Simonden,
1998). In Peru mothers will relactate if a recently weaned child falls sick
(Marquis et al 1997). Fawzi et al (1998) found that child undernutrition had no
association with prolonged breastfeeding, only with poverty and illiteracy. In
rural China exclusive breastfeeding for up to 12 months, combined with extended
breastfeeding, resulted in good growth and nutritional status (Taren & Chen
1993; Prentice 1994). In developing countries prior to the Innocenti Declaration
and the launch of the Baby Friendly Hospital Initiative, campaigns to encourage
breastfeeding for two years were successful in increasing breastfeeding rates.
As the focus shifted to the importance of exclusive breastfeeding in the early
months, breastfeeding the older child received less attention. In developed
countries also, international agencies, doctors and academics have not strongly
advocated sustained breastfeeding beyond 12 months, nor do training courses for
medical and nursing students pay enough attention to the management of sustained
breastfeeding (Haider, WHO Report 2000). Kathryn Dewey (WHO Report, 2000) points
out that while improved complementary foods along with promotion of sustained
breastfeeding show good growth effects, recommendations need to be cautious
about amounts of complementary foods to avoid displacement of breastmilk in the
infant's diet. This caution applies to Australia as when solids are introduced
to an infants diet they often replace rather than complement breastfeeding. This
may be quite deliberate with some mothers as they wish to wean their babies,
while other mothers may find their infants weaning prematurely.
Anthropologist Katherine Dettwyler (1995) posed the question of what would be
the natural age of weaning, if we were free from cultural beliefs. By looking at
age of weaning in other large mammals, particularly primates which are closest
to humans, Dettwyler estimated the natural age of weaning to be around two and a
half to seven years of age. The markers for weaning in large mammals and
primates include quadrupling of birthweight; attainment of one-third adult
weight; adult body size; gestation length; and dental eruption. In humans,
quadrupling of birthweight occurs at around 27 months for males and around 30
months for females. Dettwyler also concludes that while improved sanitation,
vaccines and antibiotics can compensate for not breastfeeding to some degree,
the physical, cognitive and emotional needs of the young child still exist.
- Anthropological evidence shows that humans have evolved to
breastfeed for several years.
- Duration of breastfeeding is affected by all aspects of our
culture. Biologically and historically and in most cultures,
sustained breastfeeding is normal.
- Those mothers from areas where sustained breastfeeding is
uncommon need to access extra support from health professionals and
support groups such as NMAA (Australian Breastfeeding Association
from August 1, 2001) and La Leche League International.
- Further research in the area of psychological, cognitive and
physical benefits to mother and child of sustained breastfeeding
would fill a gap in the knowledge of early childhood development.
The following policy statements inform health professionals, support mothers
and help to promote a change in attitudes towards sustained breastfeeding.
- The National Health and Medical Research Council in Australia (1995)
Dietary Guidelines for Children and Adolescents. (1996) Infant Feeding
Guidelines for Health Workers recommended exclusive breastfeeding for the
first four to six months (new draft guidelines [submitted for public comment
July 2001] state 'about six months') with breastmilk still the most
important part of the baby's diet for up to 12 months. Breastfeeding is then
to continue into the second year. There is no set upper age limit to
- Royal Australian College of General Practitioners. The position paper by
the Royal Australian College of General Practitioners recommended exclusive
breastfeeding for six months then gradual introduction of complementary
foods. Breastfeeding to continue for as long as the mother and child wish.
The RACGP position paper includes the UNICEF recommendation that
breastfeeding should be sustained for at least two years after six months of
- American Academy of Pediatrics 1997, Breastfeeding and the use of human
milk. Pediatrics 100(6): 1035-1039). The American Academy of Pediatrics
recommended gradual introduction of solid foods in the second half of the
first year. Breastfeeding to continue for at least 12 months and then for as
long as mutually desired.
- The World Health Organisation recommended 6 months of exclusive
breastfeeding, then breastfeeding to two years and beyond in addition to
appropriate complementary foods (WHA54.2 May 2001).
- Ainsworth MA 1973, The development of infant-mother attachment. In
Caldwell BM, Ricciuti HN (eds): Review of Child Development Research,
University of Chicago Press, Chicago.
- Backstrom MC, Maki R, Kuusela A, Sievanen H, Koivisto A, Koskinnen M,
Ikonen RS, Maki M 1999, The long term effect of early mineral, vitamin D,
and breast milk intake on bone mineral status in 9 to 11-year-old children
born prematurely. J Pediatr Gastroentrol Nutr 29: 575-582.
- Boulton J, Landers M 1999, The Toowoomba Children's Nutrition Study
1993-1997. Darling Downs Public Health Unit, Toowoomba.
- Bruining GJ 2000, Association between infant growth before onset of
juvenile type-1 diabetes and autoantibodies to IA-2. Lancet 356: 655-656.
- Detwyler K 1995, A time to wean. In Stuart-Macadam P, Dettwyler K (eds)
Breastfeeding Biocultural Perspectives. Aldine De Gruyter, New York.
- Dewey KG, Wesseling W, Heinig MJ 1995, Do infant intake and growth rate
change after termination of breastfeeding in the second year of life? FASEB
Journal 9: A755 (abstract).
- Donath S, Amir LH 2000, Rates of breastfeeding in Australia by State and
socio-economic status: Evidence from the 1995 National Health Survey. J
Paediatr Child Health 36: 164-168.
- Fawzi WW, Herrera MG, Nestel P, el Amin A, Mohamed KA 1998, A
longitudinal study of prolonged breastfeeding in relation to child
undernutrition. Int J Epidemiol 27(2): 255-260.
- Fergussen DM, Woodward LJ 1999, Breast feeding and later psychosocial
adjustment. Paediatr Perinatol Epidemiol 13: 144-157.
- Fisher JO, Birch LL, Smiciklas-Wright H, Picciano MF 2000 Breastfeeding
through the first year predicts maternal control in feeding and subsequent
toddler energy intakes. J Am Diet Assoc 100(64): 641-646.
- Goldman AS, Goldblum RM 1983, Immunologic components in human milk
during the second year of lactation. Acta Paediatr Scand 72: 461-462.
- Gulick EE 1986, The effects of breastfeeding on toddler health. Ped Nurs
- Haggerty PA, Rutstein SO 1999, Breastfeeding and Complementary Infant
Feeding, and the Postpartum Effects of Breastfeeding. DHS Comparative
Studies No 30, Calverton, Maryland: Macro International Inc.
- Hills-Bonczyk SG, Tromiczak KR, Avery MD, Potter S, Savik K, Duckett LJ
1994, Women's experiences of breastfeeding longer than 12 months. Birth
- Horwood LJ, Darlow BA, Mogridge N 2001, Breast milk feeding and
cognitive ability at 7-8 years Arch Dis Fetal Neonatal 84: F23-F27.
- Hunter HH 1996, Parenting Scandinavian style. Breastfeeding utopia? New
Generation 15(4): 26-27.
- Kendall-Tackett KA, Sugarman M 1995, The social consequences of
long-term breastfeeding. J Hum Lact 11: 179-183.
- Kent JC, Mitoulas L, Cox DB, Owens RA, Hartmann PE 1999, Breast volume
and milk production during extended lactation in women. Exp Physiol 84:
- Kries R von, Koletzko B, Sauerwald T, Mutius E von, Barnert D, Grunert
V, Voss H von 1999, Breastfeeding and obesity: cross sectional study. BMJ
- LawrenceRA, LawrenceRM 1999, Breastfeeding: A Guide For the Medical
Profession (5th ed). CV Mosby, St Louis.
- Marangoni F, Agostoni C, Lammardo AM, et al 2000, Polyunsaturated fatty
acid concentrations in human hindmilk are stable throughout 12-months of
lactation and provide a sustained intake to the infant during exclusive
breastfeeding: an Italian study. Br J Nutr 84: 103-109.
- Marquis GS, Habicht JP, Lanata CF, Black RE, Rasmussen KM 1997,
Association of breastfeeding and stunting in Peruvian toddlers: an example
of reverse causality. Int J Epidemiol 26(2): 349-356.
- Melton LJ, Bryant SC, Wahner HW, O'Fallon WM, Malkasian GD, Judd HL,
Riggs BL 1993, Influence of breastfeeding and other reproductive factors on
bone mass later in life. Osteoporosis Int 3(2): 76-83.
- Prentice A 1991 Breastfeeding and the older infant. Acta Paediatr Scand
- Prentice A 1994, Extended breast-feeding and growth in rural China. Nutr
Rev 52(4): 144-146.
- Rogan WC and Gladen BC 1993, Breastfeeding and cognitive development.
Early Hum Dev 31: 181-193.
- Ryan AS 1997, The resurgence of breastfeeding in the United States.
Pediatrics 99(4): e12.
- Simonden KB, Simonden FS 1998, Mothers prolong breastfeeding of
undernourished children in rural Senegal. Int J Epidemiol 27(3): 490-494.
- Sinigaglia L, Varenna M et al 1996, Effect of lactation on
postmenopausal bone mineral density of the lumbar spine. J Reprod Med 41:
- Speller E 2000, Breastfeeding and Dental Caries. NMAA Hot Topic 5: 1-4.
- Taren D, Chen J 1993, A Positive association between extended
breast-feeding and nutritional status in rural Hubei Province, Peoples
Republic of China. Am J Clin Nutr 58(6): 862-867.
- WHO 2000, Report of a Technical Consultation on Infant and Young Child
- WHO 1998, Complementary Feeding of Young Children in Developing
Countries. WHO, Geneva.
- WHO/UNICEF 1993, Breastfeeding Counselling: A Training Course.
- Wrigley EA, Hutchinson SA 1990, Long-term breastfeeding. The secret
bond. J Nurs Midwifery 35(1): 35-41.
- Zetterstrom R 1999, Breastfeeding and infant -mother interaction. Acta
Paediatr S430: 1-6
- Zheng T, Duan L, Liu Y, Zhang B, Wang Y, Chen Y, Zhang Y, Owens PH 2000,
Prolonged lactation reduces breast cancer risk in Shandong Province, China.
Am J Epidem 152: 1129-1135.
- Bumgarner NJ 2000, Mothering Your Nursing Toddler (3rd ed) La Leche
League International, Illinois
- Brodribb W , Breastfeeding Management in Australia (2nd ed) 1997, Ch 6.
- ABA 2002. ,Breastfeeding Through Pregnancy and Beyond. ABA, East
- ABA, 2002, Weaning. ABA, East Malvern.
- The Lactation Resource holds 193 articles related to sustained
breastfeeding which may be of interest.