Practical Management of the Mother-Infant Nursing Couple
Management of lactation begins with understand- ing the physiologic process of suckling and the physiologic process involved in latching on to the breast. For thousands of years, women fed their young by breastfeeding. They learned the art from senior women in the family. It was not a medical issue. The social structure of the family has changed, and the natural learning pathways are gone. The physician now has a critical role in the management of human lactation.
Successful nursing depends on the successful interaction of mother and infant, with appropriate support from the father, the family, and available health care resources. Because mothers and infants vary, no simple set of rules in hospitals can be out- lined to guarantee success. In fact, one of the diffi- culties has been that rigid systems were established for initiating lactation in hospitals that did not fit all mother-infant couples. Many physicians have not received formal education about breastfeeding;
thus they resort to gaining information from a vari- ety of sources, including personal experiences, and may assume that this is the correct way to approach the situation.
Nowhere in medicine do one’s personal interests or prejudices become more evident than in the area of counseling about childbirth and breastfeeding.
Having a child does not make one an expert on the subject. Conversely, not having a child does not preclude the development of exceptional knowledge. Some of the world’s most revered experts in human lactation have neither had a child nor nursed an infant, but they have brought to the situation the eye of a skilled observer and the expe- rience of a broadly trained clinician, unencumbered by emotional bias and personal prejudices.
Historically, rigid dogmas have directed man- agement of lactation. In the effort to replace these with what was perceived as more rational manage- ment, new dogmas have arisen. Once there was a paucity of literature; now there is a deluge from all sources, some valid, others questionable. The careful art and science of breastfeeding are being lost in the rage of righteousness. No rules exist for breastfeeding. As in all other areas of medicine, a clinician adapts the recommendations to individ- ual patients and their circumstances.151
It is not ordinarily a physician’s role to teach a mother how to breastfeed. Instead, nursing staff who interact in the perinatal period, including obstetric office nursing, labor/delivery, nursery, postpartum, birth center, pediatric office personnel, and midwives, have job descriptions that include hands-on assistance for a mother in the process of breastfeeding. A physician does, however, need to understand the anatomy and physiology and the basics of breastfeeding to recognize problems and determine their solutions (Table 8-1). This chapter addresses the basic breastfeeding process.
It is not a “how-to” manual for mothers, but the physician should be familiar with one or two good sources of information to suggest for patients, such as K. Huggins’The Nursing Mother’s Companion, now in its 6th edition after 25 years of inspiring mothers to breastfeed. The Womanly Art of Breast- feeding from La Leche League International is also available.
The references for this chapter are not an exhaustive list of all material written on the topic;
rather, they are intended to assist a reader in locating research that supports the evidence-based concepts described here.108,126
230
Infant feeding and care practices were assessed by the Department of Health and Human Services and published as a supplement toPediatricsin 2008.
It documents various aspects of infant feeding, as reported by more than 2000 women nationally for 1 year postpartum in 2004 and compares results with a similar study in 1993. This report serves as a reality check for many routines held dear.36
The home access to e-technologies was evalu- ated by Laborde et al.69in France. They noted that women with available technologies were more apt to be employed, did not use pacifiers, and did not smoke. Duration of breastfeeding was not differ- ent overall, suggesting that technology has not replaced good health resources and support systems yet.28
The key to the management of the mother- infant nursing couple is establishing a sense of
confidence in the mother and supporting her with simple answers to her questions when they arise.
Good counseling also depends on understanding the science of lactation. Then, when a problem arises, a mechanism already is in place for a mother to receive help from her physician’s office before the problem creates a serious medical complication.
Peripartum Breastfeeding Management
All pregnant women should receive education about the benefits and management of breastfeed- ing to provide an opportunity to make an informed decision. The obstetrician with prenatal consulta- tion should make an assessment of the potential
TABLE 8-1 Common Breastfeeding Conditions and Symptoms and Their Connection with Breast Anatomy
Clinical Condition Symptoms Anatomic Relationship
Glandular anomaly
Hypoplasia Low milk production Possible deficiency of glandular tissue Hyperplasia Excessive breast growth, lymphedema,
possible necrosis Excess glandular tissue Breast surgery
Reduction
mammoplasty Low milk production Large volume of glandular tissue removed, severing milk ducts (fewer in number than previously thought); possible nerve damage inhibiting milk ejection reflex
Breast augmentation Low milk production Possible compression of milk ducts by implant;
possible deficiency in volume of glandular tissue Palpable mass
Blocked duct Mass (small or large) with or without pain;
possible reduction in milk production Compression of ducts: possible cause of blocked duct; if large lobe affected a significant reduction in milk production may occur; identification of the level of duct obstruction by ultrasound ensures treatment of entire affected area Galactocele Mass (generally small) Possible ductal abnormality
Benign mass (cyst, fibroadenoma)
Mass Possible compression of ducts causing blocked
duct; possible obstruction of milk flow in the area of attachment of the infant to the breast Malignant mass Palpable nonresolving mass Irregularly shaped mass that may be mistaken for a
blocked duct or galactocele; ultrasound with or without mammography needed for diagnosis Infant sucking
mechanism
Ineffective suck Lack of milk sinuses and evidence that vacuum plays a major role in milk removal may alter intervention
Milk expression Differences in efficiency of pumping Theorized that women with large milk ducts or duct dilations at milk ejection express milk quickly Differences in effectiveness of pumping Poor shield fit may result in compression of
superficial ducts and inhibit milk flow Milk ejection Time of increased milk availability Small ducts lacking lactiferous sinuses do not store
a large amount of milk; optimization of milk removal during milk ejection will improve milk removal from the breast
From Geddes DT: Inside the lactating breast: the latest anatomy research,J Midwifery Women’s Health52(6), November/
December 2007.
for successful breastfeeding if a problem is identi- fied. Labor and delivery with the presence of a doula has been shown to enhance breastfeeding.
Mode of delivery and use of anesthesia and medica- tions also impact breastfeeding. Provision for breastfeeding within the first hour of life and the availability of rooming-in are also essential. The Academy of Breastfeeding Medicine (ABM) pro- vides a helpful protocol for successful peripartum management.
A model of breastfeeding policy is also provided by the ABM, which is designed so that hospitals can incorporate it into their own policies.101 It meets requirements for the Baby Friendly Hospital Initiative.
The Science of Suckling
The ability to lactate is characteristic of all mam- mals, from the most primitive to the most advanced. The divergence of suckling patterns, however, makes it urgent that human patterns be studied specifically. Some aquatic mammals, such as whales, nurse under water; others, such as the seal and sea lion, nurse on land. A variety of erect or recumbent postures are assumed by different ter- restrial mammals.24Nursing may be continuous, as in the joey attached to a marsupial teat, or at widely different intervals characteristic of the species and parallel to the nutrient concentrations of the milk.
The intervals may be a half hour for dolphins, an hour for pigs, a day for rabbits, 2 days for tree shrews, or a week for northern fur seals.
New anatomy research gathered for the first time in 160 years since the brilliant work of Sir Ash- ley Cooper has been generated in the laboratory of Peter Hartmann in Australia and his eclectic team of scientists. They have had access to the latest dig- ital technology. They have shown that the milk ducts of the breast are small (Figure 8-1), compress- ible, superficial, and closely intertwined.40 There are no “dilated sinuses” that store large amounts of milk. The amount of adipose tissue in the breast is very variable and not a measure of the amount of glandular tissue; there is twice as much glandular tissue as fat.32 Magnetic resonance imaging has identified some central ducts in the breasts of lac- tating women. The anatomy of the lactating breast was redefined with ultrasound imaging in Hart- mann’s laboratory.103Ducts were found to number four to eight, and branches drain glandular tissue directly beneath the nipple and merge into a col- lecting duct very close to the nipple. They do increase in diameter during milk ejection. Milk pro- duction is not dependent on neural stimulation but is hormonal. Milk ejection is critical to suc- cessful lactation. Failure to remove milk results in
decreased milk production. Multiple milk ejections occur during breastfeeding, even though a women usually only senses the first milk ejection.
Although many anatomic distinctions exist as well, the principal mechanism of milk removal common to all mammals is the contractile response of the mammary myoepithelium under the hor- monal influence of oxytocin released from the neurohypophysis.145
The key function in all species is effective control of milk delivery to the young in the right amount and at the appropriate intervals, which requires a production system, exit channels, a prehensile appendage, an expulsion mechanism, and a retention mechanism. The primary, second- ary, and tertiary ducts form an uninterrupted chan- nel for the passage of milk from the milk-producing alveoli to the prehensile appendage. A process of erection of the areolar region facilitates prehension by the young during suckling. The principal object of the suction produced by the facial musculature of the young is to draw the nipple into the mouth and retain it there. Positive pressure is used to expel milk from the gland by the contractile changes in the mammary gland provided by the myoepithelial cells (see Figure 3-15). The sympathetic nervous stimuli can oppose milk ejection by increasing
Figure 8-1AandB. Ultrasound image of a main milk duct (Toshiba, Aplio). The nipple is the round hypoechoic(dark) structure in the left of the image (N). The main duct (M) branches into two ducts (B) approximately 5 mm from the nipple. Note the small diameter of the ducts (approximately 3 mm). (From Geddes DT: Inside the lactating breast: the lat- est anatomy research.J Midwifery Women’s Health52(6), November/December 2007, Figure 3.)
vasoconstrictor tone, thereby reducing access of circulating oxytocin to the mammary myoepithe- lium. Sympathetic activity also can occur during conditions of apprehension or muscular exertion.
The milk-ejection reflex can be blocked by emo- tional disturbance or reflex excitation of the neurohypophysis. The central nervous system con- trol of milk ejection indeed suggests that restrain- ing mechanisms exist to ensure that milk ejection can only occur under circumstances wholly condu- cive to the effective removal of milk by the suckling young.
In all species that have been studied, a rise in intramammary pressure and flow of milk occurs as a reflex event in suckling. The excitation of the neu- rohypophysis results in the release of oxytocin, which is conveyed via the bloodstream to mam- mary capillaries, where it evokes contraction of the myoepithelium. The successive ejection pres- sure peaks, demonstrated in lactating women, can be duplicated more accurately by a series of sepa- rate oxytocin injections than by the same total dose as a single injection or by a continuous infusion of the hormone. This strongly suggests that oxytocin is released from the neurohypophysis in spurts. The study of suckling patterns in all species shows a high degree of ritualization, which in turn suggests a close neural connection between cognitive or behavioral and hormonal responses.
Attention has focused on the mechanisms that control suckling behavior, on its incidence, on events that precipitate and terminate it, on the effects of stress, and on how development mod- ifies it. Suckling is characteristic of each species and is vital for survival. Suckling means to take nourishment at the breast and specifically refers to “breastfeeding” in all species.Sucking, however, means to draw into the mouth by means of a partial vacuum, which is the process employed when bottle feeding.Suckingalso means to consume by licking.
Although suckling has been studied in young and mothers in other species, a large portion of human data have been collected using a rubber nip- ple and bottle. Other mammals suckle only in the nutritive mode, whether receiving milk from the nipple or not. Human infants were noted to have two distinct patterns with rubber nipples: a nutri- tive mode and a nonnutritive mode.145,146 When this work was repeated using the breastfeeding model, no difference between nutritive and nonnu- tritive suckling rates, but rather a continuous varia- tion of suckling rate in response to milk-flow rate, has been seen.15 Suckling rates in other species correlate with milk composition and species- specific feeding schedules (one suck per second in great apes and four to five sucks per second in sheep and goats).
In further experiments, an inverse linear rela- tionship was found between milk flow and suckling rate. Thus the higher the milk flow, the lower the suckling rate. In human infants younger than 12 weeks of age, suckling will terminate with sleep and be reinstated on awakening, a pattern that is well described in other species. In infants older than 12 weeks, suckling is not always terminated by sleep. At 12 to 24 weeks, infants will play with the nipple, explore the mother, and not always elicit nipple attachment. Continuous measurement of milk intake during a given feeding from one breast showed a progressive reduction in intake vol- ume per suck and an increase in the proportion of time spent pausing between bursts of sucking.
Using the miniature Doppler147ultrasound flow transducer, Woolridge and Baum148studied 32 nor- mal mother-baby pairs from 5 to 9 days postpartum.
Intakes during trials averaged 34.2 g (3.7 g) on the first breast and 26.2 g (3.5 g) on the second breast. At the start of feeds, the average suck vol- ume was about 0.14 mL/suck, which decreased to about 0.10 mL/suck or less. The mean latency for release of milk was 2.2 minutes after the infant began to suckle. The researchers also noted that on the first breast the flow increased and stabilized after 2 minutes, with concomitant slowing and sta- bilizing of sucking pattern during the remainder of the feed. On the second breast the suck volume fell off dramatically toward the end of the feed (50%
reduction from peak to end of feed) (Figure 8-2).
These observations support the theory that infants become satiated at the breast, and milk remains unconsumed in the breast. During the first month of life, infants consume a given amount of fluid with decreasing investment of time.148The amount of fluid per suck increases over time. The control of intake appears to come under intrinsic control of the infant during the first month of life.98 A cineradiographic study of breastfeeding was done by Ardran et al.7in 1957 and compared with a similar study of bottle feeding.8The nipples and areolae of 41 breastfeeding mothers were coated with a paste of barium sulfate in lanolin, and cinera- diographic films were taken with the infant at breast.
These were then reviewed meticulously.Box 8-1lists the authors’ conclusions in their original description.
These observations are of historic interest, but newer techniques in imagery have more accurately des- cribed the understanding of human suckling.
The development of real-time ultrasound im- proved the definition of images. Several studies have been published using this noninvasive tech- nique to observe the action of the infant’s tongue and buccal mucosa and the maternal nipple areola.
Using a video recorder in the 1980s that allowed frame-by-frame analysis and recorded simultaneous respiration, the pattern of suck, swallow, and
breathing was documented during a period of active suckling at the breast. A suck was defined by Weber et al.137as the beginning of one inden- tation of the nipple by the tongue to the beginning of the next. Weber et al. had examined six breastfed and six bottle-fed infants between 1 and 6 days of life. Not all sucks were associated with a swallow.
Box 8-2summarizes the process.
Observations of suckling using improved tech- niques from 2 to 26 weeks showed that suckling starts with a series of fast sucking movements and then stabilizes. In a 2-week-old breastfeeding infant, sucking and breathing pattern proportions alternated smoothly at about two sucks to one breath, with swallowing occurring with every suck.
Bottle feeding patterns were variable and some- times asynchronous with sucking and breathing.
The process of suckling has been described as a pulsating process similar to peristalsis along the rest of the gastrointestinal (GI) tract. This undulating motion, as described by cineradiography, did not involve stroking or friction, as was clearly pointed out by Woolridge.147The nipple should not move in and out of the infant’s mouth if the breast is posi- tioned correctly. The tip of the tongue does not move along the nipple. The positive pressure of the tongue against the teat (areola and nipple), coupled with ejection of the milk from increased intraductal pressure, evacuates the milk, not suc- tion. The negative pressure created in the mouth holds the nipple and breast in place and reduces the “work” to refill the ducts. Visual observations and videotapes made in our laboratory to study suckling show the undulating motion of the exter- nal buccal surfaces even in newborns. Ultrasound confirms the molding of buccal mucosa and tongue around the teat, leaving no space.
In breastfeeding the tongue action is a “rolling,”
or peristaltic, action from the tip of the tongue to the base, not side to side. In bottle feeding the tongue action is more piston like or squeezing.
When the infant rests between sucks, the human nipple is indented by the tongue, and the latex teat is expanded in bottle feeding (Figures 8-3and8-4).
BOX 8-1. Radiographic Interpretation of Suckling at Breasts
1. The nipple is sucked to the back of the baby’s mouth, and a teat is formed from the nipple and the adjacent areola and underlying tissues.
2. When the jaw is raised, this teat is compressed between the upper gum and the tip of the tongue resting on the lower gum. The tongue is applied to the lower surface of the teat from the front backward, pressing it against the hard palate; the teat is reduced to approximately half its former width. As the tongue moves toward the posterior edge of the hard palate, the teat shortens and becomes thicker.
3. When the jaw is lowered, the teat is again sucked to the back of the mouth and restored to its previous size.
4. Each cycle of jaw and tongue movement takes place in approximately 1.5 seconds. The pharyngeal cavity becomes airless and the larynx closes every time the upward movement of the tongue against the teat and hard palate is completed.
40
20
0
0 2 4
50%
90%
100% feed taken First breast
7 10
mL
Minutes
40
20
0
0 2 4
50%
80%
100%
Second breast
7 10
Minutes
Figure 8-2. Mother-infant pattern of milk flow. (From Lucas A, Lucas PJ, Baum JD: Pattern of milk flow in breast-fed infants, Lancet 2:57, 1979.)
BOX 8-2. Ultrasound Interpretation of Suckling at Breasts
1. The lateral margins of the tongue cup around the nipple, creating a central trough.
2. The suck is initiated by the tip of the tongue against the nipple followed by pressure from the lower gum.
3. There is peristaltic action of the tongue toward the back of the mouth.
4. The tongue elevation continues to move the bolus of milk into the pharynx.