Don't Retract Pack

The Placenta Does Not Age or Fail Post-Dates


"A review of the available evidence indicates that the placenta does not undergo a true aging change during pregnancy. There is, in fact, no logical reason for believing that the placenta, which is a fetal organ, should age while the other fetal organs do not: the situation in which an individual organ ages within an organism that is not aged is one which does not occur in any biological system. The persisting belief in placental aging has been based on a confusion between morphological maturation and differentiation and aging, a failure to appreciate the functional resources of the organ, and an uncritical acceptance of the overly facile concept of 'placental insufficiency' as a cause of increased perinatal mortality."

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Happy Pills! One way to encapsulate on your own: http://www.DrMomma.org/2010/08/happy-pills-placenta-encapsulation.html 

Ode to My Placenta: http://www.DrMomma.org/2017/09/ode-to-my-placenta.html

The First Forty Days: The Essential Art of Nourishing the New Mother: https://amzn.to/2QtlEQg

The Fourth Trimester: A Postpartum Guide to Healing Your Body, Balancing Your Emotions, and Restoring Your Vitality: https://amzn.to/2Pys7nU

Chocolate Placenta Truffles: http://www.DrMomma.org/2012/04/chocolate-placenta-truffles.html 

Placenta - the Forgotten Chakra: https://amzn.to/2PxY0g0

Lotus Birth: http://www.DrMomma.org/2010/08/lotus-birth.html

Fish Can't See Water: The Need To Humanize Birth: http://www.DrMomma.org/2009/08/fish-cant-see-water-need-to-humanize.html

The Lie of the Estimated Due Date (EDD): http://www.DrMomma.org/2009/06/lie-of-estimated-due-date-edd-why-your.html

Why Pregnancy Due Dates are Inaccurate: http://www.DrMomma.org/2009/09/why-pregnancy-due-dates-are-inaccurate.html

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Placenta keychain (fun gift for the birth advocate in your life): https://amzn.to/2PxBF2n

Plush placenta (education, awareness raising, fun): https://amzn.to/2LaegmY

_______

Fox, Harold. Aging of the placenta. Archives of Disease in Childhood - Fetal and Neonatal Edition 1997;77:F171-F175. Full text: http://fn.bmj.com/content/77/3/F171

It is widely believed that during the relatively short duration of a normal pregnancy the placenta progressively ages and is, at term, on the verge of a decline into morphological and physiological senescence.1-3 This belief is based on the apparent convergence of clinical, structural, and functional data, all of which have been taken, rather uncritically, as supporting this concept of the placenta as an aging organ with, all too often, no distinction being made between time related changes and true aging changes. I will review some of these concepts and consider whether the placenta truly undergoes an aging process. For the purposes of this review an aging change is considered to be one which is intrinsic, detrimental, and progressive and which results in an irreversible loss of functional capacity, an impaired ability to maintain homeostasis, and decreased ability to repair damage.

Morphological changes

The placenta is unusual in so far as its basic histological structure undergoes a considerable change throughout its lifespan. For some time it has been customary to describe the appearances of the placental villi in terms of their changing appearance as pregnancy progresses, comparing, for instance, typical first trimester villi with those in third trimester placentas. It has often been implied that this changing appearance is an aging process, but it is now recognized that this temporal variability in villous appearances reflects the continual development and branching of the villous tree (fig 1) In recent years the relation between the growth of the villous tree and the villous histological appearances has been formally codified5-8with identification of five types of villi (fig 2).


Figure 1 Diagrammatic representation of a peripheral villous tree, showing a large central stem villus: the lateral branches from this are the mature intermediate villi from which the terminal villi protrude.


Figure 2  Representation of the peripheral branches of a mature villous tree together with typical cross sections of the five villous types. The figures are reproduced from Haines & Taylor. Textbook of Obstetrical and Gynaecological Pathology. 4th Edn. 1995, by kind permission of Churchill Livingstone and Professor P Kaufmann.

1 Mesenchymal villi 

These represent a transient stage in placental development and they can differentiate into either mature or immature intermediate villi. They comprise the first generation of newly formed villi and are derived from trophoblastic sprouts by mesenchymal invasion and vascularisation. They are found mainly in the early stages of pregnancy but a few may still be found at term They have complete trophoblastic mantles with many cytotrophoblastic cells and regularly dispersed nuclei in the syncytiotrophoblast: their loose, immature-type stroma is abundant and contains a few Hobauer cells, together with poorly developed fetal capillaries.

2 Immature intermediate villi 

These are peripheral extensions of the stem villi and are the predominant form seen in immature placentas. These villi have a well preserved trophoblastic mantle in which cytotrophoblastic cells are numerous; the syncytial nuclei are evenly dispersed and there are no syncytial knots or vasculo-syncytial membranes. They have an abundant loose stroma that contains many Hofbauer cells: capillaries, arterioles, and venules are present.

3 Stem villi 

These comprise the primary stems which connect the villous tree to the chorionic plate, up to four generations of short thick branches and further generations of dichotomous branches. Their principal role is to serve as a scaffolding for the peripheral villous tree, and up to one third of the total volume of the villous tissue of the mature placenta is made up of this villous type, the proportion of such villi being highest in the central subchorial portion of the villous tree. Histologically, the stem villi have a compact stroma and contain either arteries and veins or arterioles and venules; superficially located capillaries may also be present.

4  Mature intermediate villi 

These are the peripheral ramifications of the villous stems from which most terminal villi directly arise. They are large (60–150 μm in diameter) and contain capillaries admixed with small arterioles and venules, the vessels being set in a very loose stroma which occupies more than half of the villous volume. The syncytiotrophoblast has a uniform structure, no knots or vasculo-syncytial membranes being present. Up to a quarter of the villi in a mature placenta are of this type.

5 Terminal villi 

These are the final ramifications of the villous tree and are grape-like outgrowths from mature intermediate villi. They contain capillaries, many of which are sinusoidally dilated to occupy most of the cross sectional diameter of the villus. The syncytiotrophoblast is thin and the syncytial nuclei are irregularly dispersed. Syncytial knots may be present and vasculo-syncytial membranes are commonly seen. These terminal villi begin to appear at about the 27th week of gestation and account for 30–40 per cent of the villous volume, 50 per cent of the villous surface area, and 60 per cent of villi seen in cross section at term.

The pattern of development of the villous tree is therefore as follows: During the early weeks of pregnancy all the villi are of the mesenchymal type. Between the 7th and 8th weeks mesenchymal villi begin to transform into immature intermediate villi and these subsequently transform into stem villi. Development of additional immature intermediate villi from mesenchymal villi gradually ceases at the end of the second trimester, but these immature intermediate villi continue to mature into stem villi and only a few persist to term as growth zones in the centres of the lobules. At the beginning of the third trimester mesenchymal villi stop transforming into immature intermediate villi and start transforming into mature intermediate villi. The latter serve as a framework for the terminal villi which begin to appear shortly afterwards and predominate at term.

This progressive elaboration of the villous tree results in a predominance of terminal villi in the mature placenta. Such villi have been conventionally classed as “third trimester villi” and a comparison of their structure with the predominant type of villi in the first trimester— immature intermediate villi—has led many to suggest that as pregnancy progresses the villous trophoblast becomes irregularly thinned and the cytotrophoblast regresses, changes interpreted as being of an aging nature. The villous cytotrophoblast, which is a stem cell for the trophoblast, does not in reality regress, because the absolute number of these cells in the placenta is not decreased at term and in fact continues to increase throughout pregnancy. The apparent sparsity of these cells is due to their wider dispersion within a greatly increased total placental mass.9 10 The focal thinning of the villous syncytiotrophoblast apparent in many terminal villi has often been cited as evidence of syncytial senescence. These thinned areas are, in reality, the “vasculo-syncytial membranes”11 which, although formed in part by mechanical stretching of the trophoblast by ballooning capillary loops,12 never the less differ enzymatically and ultrastructurally from the non-membranous areas of the syncytium and are areas of the syncytiotrophoblast specifically differentiated for the facilitation of gas transfer.13 These membranes are therefore a manifestation of topographic functional differentiation within the trophoblast.

The interlinked, but separate, processes of maturation of the villous tree and functional differentiation of the trophoblast result in a predominant villous form that is optimally adapted for materno-fetal transfer diffusion mechanisms: the morphological changes substantially increase trophoblastic surface area14 and a significantly reduce the harmonic mean of the diffusion distance between maternal and fetal blood,15 with a resulting increase in the conductance of oxygen diffusion.16

It is not mere pedantry to distinguish between maturation, which results in increased functional efficiency, and aging, which results in decreased functional efficiency. In this respect it is worth noting that a proportion of placentas from women with severe pre-eclampsia look unusually mature for the length of the period of gestation: this is usually classed as “premature aging” but it would be more accurate to regard the changes as being due to accelerated maturation, this being a compensatory mechanism to increase the transfer capacity of the placenta in the face of an adverse maternal environment.

It has to be admitted that the control mechanisms of placental maturation are unknown. There are many agents thought to be of importance in the control of placental growth, including cytokines, growth factors, oncogenes, prostaglandins and leucotrienes,17-20 but it far from clear as to whether control of growth can be equated with control of maturation. However, villous development, certainly in the later stages of pregnancy, does seem to be driven principally by proliferation of endothelial cells and capillary growth.21 Vascular endothelial growth factors are present in placental tissue22 and the suggestion that hypoxia may stimulate angiogenesis,23 and thus have a significant role in placental development, would corroborate the accelerated placental maturation seen in some cases of maternal pre-eclampsia.

Placental growth 

It has long been maintained that placental growth and DNA synthesis cease at about the 36th week of gestation and that any subsequent increase in placental size is due to an increase in cell size rather than to an increase in the number of cells.24Simple histological examination of the term placenta will, however, serve to refute this view, because immature intermediate villi are often present in the centres of lobules and these clearly represent a persistent growth zone. Furthermore, total placental DNA content continues to increase in an almost linear manner until and beyond the 42nd week of gestation.25 This finding agrees with autoradiographic and flow cytometric studies that have shown continuing DNA synthesis in the term organ,26-28 and with morphometric investigations that have shown persistent villous growth, continuing expansion of the villous surface area, and progressive branching of the villous tree up to and beyond term.14 29

Placental growth certainly slows, but clearly does not cease, during the last few weeks of gestation, although this decline in growth rate is neither invariable nor irreversible, because the placenta can continue to increase in size if faced with an unfavourable maternal environment, such as pregnancy at high altitude, or severe maternal anaemia, while the potential for a recrudescence of growth is shown by the proliferative response to ischaemic syncytial damage. Those who contend that a decreased placental growth rate during late pregnancy is evidence of senescence often seem be comparing the placenta with an organ such as the gut, in which continuing viability depends on a constantly replicating stem cell layer producing short-lived postmitotic cells. A more apt comparison would be with an organ such as the liver, which is formed principally of long-lived postmitotic cells and which, once an optimal size has been attained to meet the metabolic demands placed on it, shows little evidence of cell proliferation while retaining a latent capacity for growth activity. There seems no good reason why the placenta, once it has reached a size sufficient to adequately meet its transfer function, should continue to grow, and the term placenta, with its considerable functional reserve capacity, has more than met this aim.

Functional activity 

There have been few vertical studies of placental function throughout pregnancy, but there is no evidence that any of the major indices of placental function decline—namely, proliferative, transfer, and secretory capacities.30 As already remarked, the diffusion conductance of the organ is increased, largely as a result of morphological changes, but there is considerable evidence that specific placental carrier mediated transfer systems are also augmented.20 The placental production of hormones continues unabated until term: the synthesis of human chorionic gonadotrophin declines towards the end of the first trimester but this is clearly due to a gene switch which results in progressively increasing secretion of human placental lactogen.

The placenta also retains its full proliferative capacity until term as shown by its ability to repair and replace, as a result of proliferation in the villous cytotrophoblastic cells, of a villous syncytiotrophoblast that has been ischaemically damaged in women with severe pre-eclampsia.13

Clinical factors 

The single most important factor leading to a belief in placental senescence has been the apparently increased fetal morbidity and mortality associated with prolonged pregnancy, this traditionally being attributed to “placental insufficiency” consequent on senescence of the organ.1 31 In the past it was thought that about 11% of pregnancies extended to or beyond the 42nd week of gestation32 33 : the introduction of a routine ultrasound examination in early pregnancy reduced the incidence of prolonged pregnancies to about 6%34 and it has even been claimed that with very accurate dating studies the incidence of truly prolonged gestations does not exceed 1%.35 This casts some doubt on the validity of a great deal of the historical information about the risks and ill effects of prolonged pregnancy, but it is never the less widely accepted that perinatal mortality increases after the 42nd week of gestation.36

Any increase in perinatal mortality after the 42nd week of gestation is due, in part, to the high incidence of fetal macrosomia: 10% of infants from prolonged pregnancies weigh over 4000 g and 1% over 4500 g and these fetuses are at particular risk of complications such as shoulder dystocia. The presence of this large number of macrosomic fetuses is a clear indication that, in this subset at least, the placenta continues to function well beyond the 40th week of gestation and remains capable of sustaining untrammelled fetal growth.

The classic clinical syndrome of the “postmature” infant1 31 is not commonly seen today but seems to be clearly related to the development of oligohydramnios. There is no doubt that amniotic fluid volume tends to decrease in a proportion of prolonged pregnancies39 and that oligohydramnios is associated with a high incidence of fetal heart rate decelerations.36 This has been attributed by some to cord compression,40 41 but one study, while confirming that cord compression is common in prolonged pregnancies, was unable to correlate such compression with fetal acidosis.42 It is often assumed, and indeed commonly stated, that the decline in amniotic fluid volume in these cases is an indication of “placental insufficiency” but, in reality, there is no evidence that in late pregnancy the placenta plays any part in the production of amniotic fluid or in the control of amniotic fluid volume. 43

The two most potent causes of increased morbidity in prolonged pregnancy are therefore clearly unrelated to any change in placental functional capacity. Examination of placentas from prolonged pregnancies shows no evidence of any increased incidence of gross placental abnormalities, such as infarcts, calcification, or massive perivillous fibrin deposition. The most characteristic histological abnormality, found in a proportion of cases but certainly not in all, is decreased fetal perfusion of the placental villi.13 The fetal villous vessels are normal in placentas from prolonged pregnancies44 and Doppler flow velocimetry studies have, in general but not unanimously, indicated that there is no increased fetal vascular resistance in such placentas.45-47 The decreased fetal perfusion is therefore probably a consequence of oligohydramnios, because umbilical vein flow studies have shown that fetal blood flow to the placenta is often reduced in cases of oligohydramnios.48

It has to be admitted that the pathophysiology of prolonged pregnancy has not been fully elucidated. It seems, however, quite clear that any ill effects which may befall the fetus in prolonged gestations can not be attributed to placental insufficiency or senescence.

Conclusions 

A review of the available evidence indicates that the placenta does not undergo a true aging change during pregnancy. There is, in fact, no logical reason for believing that the placenta, which is a fetal organ, should age while the other fetal organs do not: the situation in which an individual organ ages within an organism that is not aged is one which does not occur in any biological system. The persisting belief in placental aging has been based on a confusion between morphological maturation and differentiation and aging, a failure to appreciate the functional resources of the organ, and an uncritical acceptance of the overly facile concept of “placental insufficiency” as a cause of increased perinatal mortality.

References 

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Vincent RA, Huang PC, Parmley TH (1976) Proliferative capacity of cell cultures derived from the human placenta. In Vitro 32:649–653.

Rosso P (1976) Plaenta as an ageing organ. Curr Concept Nutr 4:23–41.

Kaufmann P (1982) Development and differentiation of the human placental villous tree. Bibl Anat 22:29–39.

Kaufmann P, Sen DK, Schweikhart G (1979) Classification of human placental villi. I. Histology and scanning electron microscopy. Cell Tissue Res 200:409–423.

Sen DK, Kaufmann P, Schweikhart (1979) Classification of human placental villi.II. Morphometry. Cell Tissue Res 200:425–434.

Castelluchi M, Scheper M, Scheffen I, Calona A, Kaufmann P (1990) The development of the human placental villous tree. Anat Embryol 181:117–128.

Kosanke G, Castelluchi M, Kaufmann P, Minirov VA (1993) Branching patterns of human placental villous tree: perpectives of topological analysis. Placenta 14:591–604.

Simpson RA, Mayhew TM, Barnes PR (1992) From 13 weeks to term, the trophoblast of human placenta grows by the continuous recruitment of new proliferative units: a study of nuclear number using the dissector. Placenta 13:501–512.

Mayhew TM, Simpson RA (1994) Quantitative evidence for the spatial dispersal of trophoblast nuclei in human placental villi during gestation. Placenta 15:837–844.

Getzowa S, Sadowsky A (1950) On the structure of the human placenta with full term and immature foetus, Living or dead. J Obstet Gynaecol Brit Emp 57:388–396.

Burton GJ, Tham SW (1992) The formation of vasculosyncytial membranes in the human placenta. J Devel Physiol 18:43–47.

Fox H (1997) Pathology of the placenta. (WB Saunders, London), 2nd edn.

Boyd PA (1984) Quantitative studies of the normal human placenta from 10 weeks of gestation to term. Early Hum Devel 9:297–307.

Fenley MR, Burton GJ (1991) Villous composition and membrane thickness in the human placenta at term: a stereological study using unbiased eximators and optimal fixation techniques. Placenta 12:131–142.

Mayhew TM, Jackson MR, Boyd PA (1993) Changes in oxygen diffusive conductances of human placentae during gestation (10-41 weeks) are commensurate with the gain in fetal weight. Placenta 14:51–61.

Ohlsson R (1989) Growth factors, protooncogenes and human placental development. Cellular Differential Development 28:1–16.

Redman CWG, Sargent IL, Starkey PMOhlsson R, Glaer A, Holmgren L, Franklin G (1993) The molecular biology of placental development. in The human placenta. eds Redman CWG, Sargent IL, Starkey PM (Blackwells, Oxford), pp 33–81.

Mitchell MD, Trautman DS, Dudley DJ (1993) Cytokine networking in the placenta. Placenta 14:249–275.

Schneider H (1996) Ontogenic changes in the nutritive function of the placenta. Placenta 17:15–26.

Kaufmann P, Luckhardt M, Leiser R (1988) Three dimensional representation of the fetal vessel system in the human placenta. Troph Res 3:113–137.

Anthony FW, Wheeler T, Elcock CL, et al. (1994) Identification of specific pattern of VEGF mRNA expression in human placenta and cultured placental fibroblast. Placenta 15:561–562.

Wheeler T, Elcock CL, Anthony FW (1995) Angiogenesis and the placental environement. Placenta 16:289–296.

Winick M, Coscia A, Noble A (1967) Cellular growth in human placenta. 1. Normal cellular growth. Pediatrics 39:248–251.

Sands J, Dobbing J (1985) Continuing growth and development of third trimester human placenta. Placenta 6:13–22.

Geier G, Schuhmann R, Kraus H (1975) Regionale unterschliedliche Zellproliferation innerhalb der Plazentome reifer menschlicher Plazenten: autoradiographische Untersuchungen. Arch Gynakol 218:31–37.

Hustin J, Foedart JM, Lambotte R (1984) Cellular proliferation in villi of normal and pathological pregnancies. Gynecol Obstet Invest 17:1–9.

Iverson IE, Farsund T (1985) Flow cytometry in the assessment of human placental growth. Acta Obstet Gynecol Scand 64:605–607.

Jackson MR, Mayhew TM, Boyd PA (1992) A quantitative description of the elaboration and maturation of villi from 10 weeks of gestation to term. Placenta 13:357–370.

Beaconsfield P, Villee CFox H (1993) The placenta as a model for organ aging. in Placenta–a neglected experimental animal. eds Beaconsfield P, Villee C (Pergamon, Oxford), pp 351–378.

Voherr H (1975) Placental insuffficiency and postmaturity. Eur J Obstet Gynecol Reprod Biol 5:109–122.

Bolte A, Bachmann KD, Hofmann E, Rohricht J, Strothmann G (1972) Verlangerte Schwangerschaftsdauer und Placentadysfunktion. I. Haufigkeit und und Diagnostik bei den Geburtsjahrgangen 1955-1996. Deutsche Med Wochenschrift 97:671–675.

Perkins RP (1974) Antenatal assessment of fetal maturity: a review. Obstet Gynecol Surv 29:369–384.

Cardozo L, Fysh J, Pearce JM (1986) Prolonged pregnancy: the management debate. BMJ 293:1059–1063.

Boyd ME, Usher RH, McLean FH, Kramer MS (1988) Obstetric consequences of post maturity. Am J Obstet Gynecol 157:334–338.

Chamberlain GCardozo L (1995) Prolonged pregnancy. in Turnbull’s Obstetrics, ed Chamberlain G (Churchill Livingstone, Edinburgh), 2nd edn. pp 633–643.

Spellacy WNG, Miller MS, Winegar A, et al. (1985) Macrosomia: maternal characteristics and infant complications. Obstet Gynecol 66:158–161.

Modanlou HK, Dorchester WL, Thorosian A, Freeman RK (1980) Macrosomia: maternal, fetal and neonatal considerations. Obstet Gynecol 55:420–423.

Phelan JP, Smith CV, Broussard P, Sucell M (1987) Amniotic fluid volume assessment with the four quadrant technique at 36-42 weeks gestation. J Reprod Med 32:540–543.

Gabbe SG, Ettinger BB, Freeman RK, Makrhn CB (1977) Umbilical cord compression associated with amniotomy: laboratory observations. Am J Obstet Gynecol 126:353–355.

Leveno KJ, Quirk JG, Jnr, Cunningham FG, et al. (1984) Prolonged pregnancy. I. Observations concerning the causes of fetal distress. Am J Obstet Gynecol 150:465–473.

Silver RK, Dooley SJ, MacGregor SN, Depp R (1988) Fetal acidosis in prolonged pregnancy cannot be atributed to cord compression alone. Am J Obstet Gynecol 159:666–669.

Fox HHytten F (1987) Physiology and pathology of amniotic fluid formation. in Haines and Taylor: obstetrical and gynaecological pathology. ed Fox H (Churchill Livingstone, Edinburgh), 3rd edn. pp 1177–1182.

Larsen LG, Clausen HV, Anderson B, Graem N (1995) A stereologic study of postmature placentas fixed by dual perfusion. Am J Obstet Gynecol 175:500–507.

Guidetti DA, Divon MY, Cavalieri RL, Langer O, Merkatz IR (1987) Fetal umbilical artery flow velocimetry in postdate pregnancies. Am J Obstet Gynecol 157:1521–1523.

Stokes HJ, Roberts RV, Newnham JP (1991) Doppler flow waveform velocity analysis in post-date pregnancies. Aust N Z J Obstet Gynaecol 31:27–30.

Zimmermann P, Alback T, Koskinen J, et al. (1995) Doppler flow velocimetry of the umbilical artery, uteroplacental arteries and fetal middle cerebral artery in prolonged pregnancy. Ultrasound Obstet Gynecol 5:189–197.

Gill RW, Warren PS, Garrett WJ, Kossoff G, Stewart A (1993) Umbilical vein blood flow. Chervenack FA, Isaacson GC, Campbell S. eds. Ultrasound in obstetrics and gynecology. (Little, Brown, Boston), pp 587–595.

Natural Weaning

Excerpted with permission from the excellent book, Mothering Your Nursing Toddler, by Norma Jane Bumgarner and published by La Leche League International. Visit the Mothering Your Nursing Toddler website here, or purchase Bumgarner's book on Amazon. See also: THE JOY OF NURSING TODDLERS





The Child under Three
 
Because of the good results, both for their children and for themselves, parents are becoming more comfortable with allowing nursing to take its course and waiting for weaning to occur on its own. Some people choose such an approach because it makes the most sense to them, as did the mother who writes, "She hasn't shown any signs of weaning, and I'm not going to push it. Why put a strain into a so-far carefree experience? I believe it should end as it started – naturally." Others, like one mother of six, have more practical reasons. "She'll have to wean herself," she says. "I don't have the time to worry about it, and it doesn't matter." For these reasons and others, more children these days have the good fortune to be born into families in which they do not have to give up nursing in anyone's time but their own.

A few children, of course, come to a spontaneous finish to their nursing before their second birthday. For the few who leave behind this part of their babyhood very early it will be in some other behavior that parents will likely see signs of their immaturity for some time yet. They will continue to need babying, but they will need it in other ways.

One mother, disappointed when her fourteen-month-old weaned, realizes now that weaning came from her approach to breastfeeding, not an active weaning campaign. She emphasized solids, offered other food before nursing once her child was eating solids, and did not nurse her child just for comfort. As this mother found out, children who start taking other foods and liquids before four to six months may come to depend upon these foods for most of their nourishment in the second half of their first year, a time when most nurslings still thrive for the most part on mother's milk. Often, children who take in a great deal of food and liquid other than mother's milk at six to twelve months tend to lose interest in nursing sooner than they might have otherwise. They will wean from the breast and cling to other objects for comfort.

Some children seem less interested in nursing and become easily distracted sometime between nine and fourteen months of age. Many advisers suggest that you take advantage of your child's decreased interest, if in fact her interest does show a decrease, to initiate weaning. If you don't want to nurse a toddler, this may be the least traumatic weaning time there will be for at least two or three years. But if you expect to find it easier to care for your child if she continues nursing, do not hesitate to remind her to nurse a few times daily until she outgrows this phase. If you do not want to wean, the time around nine months, a little later sometimes, may be a sort of danger time in which you may want to make sure your nursing relationship is not interrupted or disturbed.

Most children nurse without a pause through the months before and after their first birthdays, and a very few will wean in spite of efforts to the contrary, but you can nearly eliminate the possibility that your child might wean prematurely just by offering the breast a few times a day during those weeks or months.

Most youngsters around their first birthday still enjoy receiving a nice tummy full of milk when they nurse, and if other forms of feeding and sucking take the place of feedings at the breast, there will be, as a direct result, less of the milk that so many of these children look for. This is an effective way to encourage weaning, whether that is what mother has in mind or not. For many children such a pattern constitutes a satisfactory parent-initiated weaning. Also, if bottles and pacifiers are handy to offer children, mothers are likely to make use of them to put off a feeding while finishing this or that project they are working on. This also will lead to an earlier weaning, whether intended or not.

The way to achieve a natural weaning, if that is your objective, is to feed and care for your infant without contrived interferences. Nurse on demand from birth. Forget about other foods until your child shows he is ready for them (and not before a minimum six to twelve months of age). Then feed your child sensibly. Eating foods other than your milk in the first year is more for fun than for nourishment. Except in very hot weather, a baby who nurses often but has begun to ask for other foods does not need any more liquids besides your milk than he mooches from your cup or glass. Quenching his thirst with water or juice in a sippy cup can result in less interest in nursing. An excellent way to avoid overfeeding or over-watering your baby is to make tasty foods available and attractive, but let her feed herself, in her own way, and in her own time.

Unless you are in a situation where you absolutely cannot nurse your baby, a pacifier is no help to you or to your baby. It is mostly a nuisance that, unlike your breast, is always getting dirty or lost. There is no need for bottles, either. Both pacifiers and bottles tend to become mother substitutes and are not satisfactory replacements for the full embrace of nursing.

Without the distraction and confusion brought on by pacifiers, bottles, and too much other food too soon, your child can nurse and wean in his own time and have a chance to outgrow his baby needs so completely that he can leave them behind, whether that be in his second year, or fourth, or whenever.

Not all children give up nursing gradually. Some children seem to reach a new plateau in maturity all at once and turn their backs on this or that baby behavior seemingly overnight. One mother writes of her two- year-old:

He had always nursed to sleep, but one afternoon he got two new trucks and was afraid his brother would take them while he was asleep. When I sat down to nurse him he pushed me away, took a truck in each hand, and plopped down on the bed. He never nursed to sleep after that, though he did not wean from other nursings for several months.

It is very common for little people to toilet-train themselves all at once. A few children also wean this way, especially when they are not nursing very often anyway. Surprisingly, the events that can bring on weaning in a child who is ready may be the same ones that may cause an increase in nursing at an earlier stage. A new baby, a move to a new home, or lots of company, often threatening to very little people, may at other times be so exciting and pleasant to your older child that he will drop nursing to have more time to devote to the happy new circumstances. If your child is weaning quickly just because that is her way of doing things, and if your breasts do not become overfull, then let the matter rest and go on to other ways of being with your child.

After Three
 
Most of my experience is with children who weaned between three and four, but clinical observations and research suggest that completely child-led weaning is unlikely to take place before the child turns four. (1, 2) Mothers in East Bhutan, where nursing well into childhood is socially acceptable, say that self-weaning usually occurs between three and five years. (3) In any case, weaning may come dramatically enough that your child will brag about it as one little girl did, telling her grandmother, "I'm going to be a big sister when I'm almost four – and now I'm weaned!" Or it may be so gradual that no one will know for sure when it happened.

For most children in this age range weaning is a slow, unpatterned change in behavior, so unpredictable that it is not always even headed in the same direction. At times, maybe even for long periods, your child will nurse frequently and intensely. When conditions change, either around your child or as a result of his own growth, he will begin to prefer other things over nursing – playing, eating, sleeping, or even cuddling with you sometimes. Then things may change again for him so that he needs to be at your breast almost as often as before.

As the weeks go on, though, there will be movement, whether you notice it or not, away from many periods of frequent nursing toward more periods of less nursing. In some children this movement is regular and swift. In others it is so erratic and unpredictable that it is easy to understand how people come to believe some children would never wean without urging. Some children even wean from one breast long before the other.

Such is the unpredictable course of an uncoerced weaning. At some age, very young or "shockingly old," your child will not find nursing so absolutely essential to her well-being. And you may even miss it, as did a mother in India, who found herself unable to answer her e-mail messages as soon as she had gotten used to:

You know how things get with a busy four-year-old around the place! Sadly he's stopped automatically latching on when he sees me sit down at the computer, and pulls me off to play instead!

Your child may be distracted from nursing by anything and everything. You can see that, though he may have some months to go yet, he is on his way toward a time when he will no longer need you in this exact way.

Is child-led weaning completely child-led? Yes and no, depending on your definition. You will probably respond, and appropriately so, to your child's increasing distractibility as he matures. He may pull you to your favorite nursing spot, sit you down, latch on, and then instantly abandon you to chase his sister or watch a TV commercial. When this has happened several times, you will very naturally and with hardly a thought respond less quickly to his requests to nurse, at least when he seems to be asking rather superficially, and when the world around the two of you is busy and interesting. In this way, even without planning it, you play your part in his weaning. You are following his cues and your own common sense.

You will probably come to a time when you yourself are impatient with nursing. If you have been enjoying loving your child this way, you may be puzzled at the change in your feelings. No doubt your impatience will flare at times and subside at others, depending on what is going on in the rest of your life. Some of what you may be feeling, though, is part of natural weaning and an indication that you are gradually outgrowing the relationship. You too are growing toward being ready when the time for weaning comes.

In time – how much time no one can say – your child will abandon all but a very few favorite nursing times, usually the times when he is falling asleep or first waking up in the morning. When you are down to these few times, your milk production will dwindle. Then some children who have especially liked the milk will quit nursing in favor of a breakfast or bedtime snack. Others continue to enjoy one or more of these special nursing times for a long time yet, dropping them slowly until a few days, then a few weeks, go by with no request to nurse.

Every spontaneous weaning is unique, however, so it is impossible to guarantee anything about it except that it will happen.

Resuming Nursing after Weaning
 
For most children before age three or so, weaning, spontaneous or mother-initiated, is all but final when two or three weeks have passed without your child's tugging your shirt. After this amount of time most of these little ones do not ask again, or if they do, they find they have forgotten how to suckle. "Is it broken?" one little guy asked when he could not remember after a year just how to go about nursing.

Once in a while someone suggests that your milk may become "poison" or "spoiled" if your child does not nurse for some certain amount of time. This is an old wives' tale, one that is heard in many parts of the world. In rural Zimbabwe, for instance, mothers are told that if milk remains in the breast for a whole day, it will hurt the child. (4) But you can be assured that milk doesn't spoil in the breasts any more than blood does in the veins. Your child can nurse safely after any interval.

Occasionally a child will ask to nurse again after you have regarded her as totally weaned, but most forget how. A mother who was sad because her body just would not cooperate with her son's need to nurse during her pregnancy wrote:

I still have regrets because I see many LLL moms nursing their two-and-a-half-year-old sons, and I know that if I hadn't gotten pregnant I'd be nursing my son too. I think it would help because he doesn't talk, and it would be a great way to stay connected to him. He has tried to nurse since the new baby was born two months ago, but he doesn't remember how. I let him try whenever he wants (it's not very often).

The most likely circumstance for such requests is when you have a new baby, but also once in a while when a child discovers that mom is pregnant. Or your child may be upset about something, as in this situation recalled by the mother of a now grown daughter:

It was a disastrous time ending up with a breast abscess and an angry weaning at about two-and-a-half. She missed nursing so much though that we gradually started up again, nursed through a pregnancy and tandem nursed. She finally weaned by contract a couple months after her sixth birthday.

There is no reason that you can't allow your child to try nursing again, even though you have probably told all the relatives he is weaned. Chances are that he is weaned. A request to nurse from a child who has not nursed for a while is usually a request for reassurance and acceptance. You may not be able to discover any explanation for your child's desire to return to nursing other than the mysterious workings of his growing little mind. It feels good to a little child to know that if he ever did need you again that way, you would be there for him with open arms. One mother says of her weaned twins that they both had to try nursing several times when the new baby came, but gave it up after a few tries. It is much easier for a little person to wean himself if he knows that his decision does not have to be final.

One mother had nothing but positive feelings when her child wanted to nurse again a few times after over a year without asking for the breast: "I never realized just how important and memorable those nursing days were to her and that she would actually remember at all. This was her 'thank you' for the loving patience and time I took when it was needed." A brief return to the mostly outgrown way of loving can be a chance for mother and little one together to enjoy a bit of reminiscing.

Another mother writes of a child who resumed nursing – sort of:

When our daughter was about eleven months, [her two-year-old brother] started to become very interested in what nursing was. He shocked me one day by pretending to nurse on one breast while his sister was at the other. I didn't try to discourage him because by now I had read a little about tandem nursing and I hoped if he was to start nursing again after two years that it would help our relationship. I had already noticed the difference between my two children's behavior that I attribute to our nursing relationship. My son is a very energetic boy who likes to tell me "No!" as often as possible while my daughter is helpful and calm most of the time.

Now that she is fifteen months and he is two-and-a-half years old, he still continues to pretend but doesn't actually latch on. He even tells Baby, as he calls his sister, that it is time to nurse and he directs her to the breast he chooses. I am kind of sad that I didn't nurse him as long as I have nursed his sister but it is wonderful that he has joined our breastfeeding relationship.

For a child who is apparently weaned to actually resume nursing for a while, sometimes for no reason that you can perceive, might make you feel panicky, especially if you are very happy for your child to relate to you in a different way. Yet it will be helpful to your child for you to go along with him if you can. Just as we adults sometimes make a mistake in deciding to wean our children too soon, occasionally very small growing people make mistakes in deciding to wean themselves too soon. There is a reason, no doubt, whether we can see it with our adult eyes or not, that your child needs to nurse again for a while.

Although it may seem like it at first, you and your child are not going back to the beginning of the weaning process. After a few days of adjustment your child is not likely to nurse any more than do other children his age. He is not returning to babyhood, but picking up a behavior that is appropriate for his age. He will nurse and wean also in a way appropriate to his age – maybe in the next few days, or maybe some months hence.

Weaning need not be any more dramatic and final than toilet-training. We are not surprised when a child who is supposedly toilet-trained forgets and "backslides" for a while. It should be no more disconcerting that a weaned child would remember and nurse when he needs to. In a household with a new baby, being welcome at mother's breast, if he feels the need, can be quite a help in overcoming a child's feeling of displacement. There is no harm done by stepping back to baby things for a while – and considerable good in the long run.

Spontaneous Weaning in Children over Four
 
We commonly hear that most younger children do not ask to nurse again after they are weaned because they forget about nursing. This may be true, though I am not sure. It is certain, however, that children over four (or even over three sometimes) do not forget. As I have said, many of them will remember nursing as long as they live. So it should not be surprising that children over four are notorious for going about weaning each in their own way. Many seem to give a lot of consideration to weaning. One little girl, asked when she would wean, thought about it and then replied, "Oh, probably I will try when I'm five, 'cause you can't come to school – can you?!"

Children usually wean at a time that is easy for them, when their lives are otherwise stable. From their behavior it is often evident that they are making quite a rational choice for so young a person. Some children tell their parents that they are weaning because they themselves decided to do so, and it is easy to see from watching other children that this is the case with them as well. In some children the process that leads to weaning is not readily apparent; but this is probably not because it is so much different for them, but because they are children who keep their own counsel about it.

In the months that follow a decision to wean (or at least what appears to be such a decision) many children encounter rough spots that cause them to reconsider. These times can worry you if you have regarded the child as weaned. But you have not lost progress toward weaning. A child this age who goes weeks or months without nursing is definitely working on growing up. When she asks to nurse again after such a long time you can be sure that she has just come to a time in her life which she can handle better if she can still nurse a bit. Once she works her way past it, she will get back to the business of weaning.

Many mothers are quite hesitant to say that their over-fours are weaned, even after months without nursing. So often it seems that the minute mother pronounces her child weaned, he needs to nurse again. Needless to say, spontaneous weaning with older nurslings can be gradual indeed!


References

1. Lawrence, R. A. and Lawrence, R. M. Breastfeeding: A Guide for the Medical Profession. 5th edition. St. Louis: The C. V. Mosby Company, 1994; 345.

2. Sugarman, M. and Kendall-Tackett, K. A. Weaning ages in a sample of American women who practice extended breastfeeding. Clinical Pediatrics 1995; 34(12):646.

3. Behler, E, and Ingstad, B. The struggle of weaning: Factors determining breastfeeding duration in East Bhutan. Social Science and Medicine 1996; 43(12):1809.

4. Cosminsky, S., Mhloyi, M, and Ewbank, D. Child feeding practices in a rural area of Zimbabwe. Social Science and Medicine April 1993; 36(7):944.


Mothering Your Nursing Toddler on Amazon, or at the MYN Toddler website today.


Additional Information on Natural Weaning and Nursing Strikes:

A Natural Age of Weaning

A Time to Wean

How Weaning Happens (book)

Natural Weaning Age (pdf) from The Baby Bond (book)

The Joy of Nursing Toddlers (Add your photo!)

Do Babies Under 12 months self-wean? (KellyMom)

Breastfeeding Older Children (book)

Adventures in Tandem Nursing (book)

La Leche League International Nursing Strike FAQ

Is Your Baby on a Nursing Strike?


Toddler Nursing Strike

Is Your Baby on a Nursing Strike?


Help! My Baby Won't Nurse (KellyMom)

Surviving a Nursing Strike

Breastfeeding Latch Trick (if baby is young and latch is a problem)

When a Baby Won't Nurse

La Leche League International: Helping Babies Reluctant to Nursing


Helpful books, articles and websites for nursing mothers linked at Breastfeeding Resources

Nursing mothers are welcome to join the Breastfeeding Group





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