Breastfeeding the preterm infant

INTRODUCTION — Human milk is recognized as the optimal feeding for all infants because of its proven health benefits to infants and their mothers [1-4]. Human milk is particularly beneficial for preterm infants because of its protective effects against several comorbidities including necrotizing enterocolitis. (See "Infant benefits of breastfeeding" and "Human milk feeding and fortification of human milk for premature infants", section on 'Benefits of mother's milk'.)

Breastfeeding the premature infant, including strategies to address the challenges unique to the infant-mother pair, will be reviewed here. Other topics with related information are:

●(See "Human milk feeding and fortification of human milk for premature infants".)

●(See "Approach to enteral nutrition in the premature infant".) – Focuses on enteral feeds in the neonatal intensive care unit (NICU)

●(See "Breast milk expression for the preterm infant".)

●(See "Growth management in preterm infants".) – Focuses on feeding after NICU discharge

In this topic review, we use the term "mother" to refer to the lactating person and "breastfeeding" to refer to feeding an infant at the breast or chest.

PARENTAL COUNSELING AND SUPPORT — Counseling to parents focuses on the unique challenges to breastfeeding a preterm infant. These include:

●Because of the premature delivery, the mother had shortened prenatal care and may not have a fully informed decision about whether to breastfeed.

●Due to separation from her infant, the mother who intends to breastfeed must initially express her milk, which requires considerable time and effort during the neonatal intensive care (NICU) stay. (See "Breast milk expression for the preterm infant".)

●As a result of the infant's immature sucking ability, direct breastfeeding will be delayed after birth.

●The separation of the mother from her infant during the NICU hospital stay may lead to increased maternal stress and anxiety.

These challenges result in a decreased rate of breastfeeding in preterm compared with term infants [1,5,6]. In the NICU, special efforts are needed to address these challenges and provide breastfeeding support and education [7,8]. Clinical staff should discuss the benefits of human milk, including the long-term effects of exclusive breastfeeding, while explaining to families the need to provide fortifiers or other supplements for infants with very low birth weight and some larger preterm infants. In most cases, mothers opt to feed their infant breast milk and are willing to take the necessary steps to make this possible when they learn about the benefits of human milk [9,10]. Use of mother's own milk is optimal, but pasteurized donor breast milk can be used as a bridge to maintain an exclusively human milk diet while mother's own milk volume increases [1]. (See "Human milk feeding and fortification of human milk for premature infants".)

The efforts to promote human milk feeding should be directed and coordinated by a clinician with expertise in both lactation and intensive neonatal care. Staff should have a comprehensive understanding of the benefits of human milk, and the policy and procedures of the lactation support service, and be trained to implement the policy [8,11]. Optimal care practice policy, which promotes breastfeeding, is outlined in the criteria required for the World Health Organization Baby-Friendly Hospital Initiative and is discussed separately. Ideally, all mothers of preterm infants should have access to expert lactation care, regardless of other risk factors. (See "Initiation of breastfeeding", section on 'Hospital policy and environment'.)

BREASTFEEDING INITIATION FOR PRETERM INFANTS — Implementation of breastfeeding for the preterm infant (born <34 weeks gestation) involves the following steps:

●Assess readiness to feed based on oral behaviors and skills

●Initiate breastfeeding with guidance to compensate for the infant's immaturity

●Transition to full breastfeeding with close monitoring to ensure adequate intake

Readiness — There are no universally established criteria for when oral feedings for preterm infants should be started, and neonatal intensive care units (NICUs) utilize different protocols for initiating oral feeds. Most NICUs focus on using the infant's cues for feeding readiness as a key factor in determining timing [12-14].

Gestational age — The earliest gestational age (based on postmenstrual weeks) at which preterm infants can successfully take oral feedings via breast or artificial nipple is variable. Oral feedings often are initiated at 32 to 34 postmenstrual weeks, an age at which suckling is similar to that of term infants, except that it occurs in shorter bursts. Some infants can take a portion of their feeds orally at an earlier age.

Oral behaviors — Postmenstrual age is an unreliable marker of infant oral feeding ability [15]. Oral behaviors, such as nonnutritive sucking and rooting, appear to be better indicators of readiness to feed. These behaviors may be present in some infants as early as 28 weeks postmenstrual age. For example, in a study of 71 singleton preterm infants (born between 27 to 36 weeks postmenstrual age), rooting, areolar grasp, and latch were observed at 28 weeks postmenstrual age and nutritive sucking at 31 weeks postmenstrual age [16]. Breastfeeding was initiated between 28 and 36 weeks postmenstrual age.

Nonnutritive sucking/early suckling at breast — As soon as early indicators of readiness are noted, early suckling at the breast and nonnutritive sucking (eg, sucking on a pacifier) should be encouraged. Early and regular sucking attempts may enhance the transition from tube feeding to oral feeding by promoting maturation of oral feeding behaviors [17-21]. Moreover, early suckling promotes maternal-infant bonding, may promote milk production by stimulating the nipple, and provides an opportunity to observe the infant's behavior and track developing oral skills as an indication of readiness for oral feeding. (See "Breast milk expression for the preterm infant", section on 'Suckling to provide tactile nipple stimulation'.)

Suckling at the breast is an optimal form of early sucking for preterm infants [22]. This is a form of nutritive suckling since some milk transfer occurs even when the mother has expressed her milk before the feeding attempt. Early suckling is initiated by placement of the infant at the breast after the mother expresses milk. Although the infant should be held in proximity to the breast, no attempt should be made to "position" the infant's mouth and gums over the nipple and areola. Instead, licking and suckling on the nipple tip is all that is expected during the initial sessions. When the mother is not available, nonnutritive suckling on a pacifier is recommended.

Initiation of breastfeeding — When the preterm infant is deemed ready to begin oral feedings (eg, ability to locate and latch on to the breast), breastfeeding may be initiated directly. The breastfeeding technique is similar to that for term infants, but the mother requires specialized instruction and support, including:

●Feeding cues – The parent(s) should learn to recognize the infant's feeding readiness cues (eg, drowsy/alert, rooting, hand to mouth) and signs to pause or stop feeding (eg, decreased tone, gagging, avoidance behaviors, etc).

●Positioning – The cross-cradle (sitting) or clutch (football) positions are often best for preterm infants because they provide support to the head and neck. These positions give the mother more control in placing the baby in an optimal position and maintaining the alignment of the infant's torso at the breast.

●Achieving an effective latch and milk transfer – Preterm infants tend to have low sucking pressure and immature suckling patterns, which present challenges for the infant to maintain an effective and sustained latch to the breast. Strategies to manage these issues include optimizing breastfeeding technique and positioning and/or use of a nipple shield. In some cases, milk ejection can compensate for marginally effective suckling because some infants can still consume an adequate quantity of milk during breastfeeding if the mother has a copious milk volume that flows readily. (See 'Problems with milk transfer' below.)

●Assessing the infant's milk intake. (See 'Assessment of milk intake' below.)

Breastfeeding technique, including positioning and achieving an effective latch, is described in greater detail separately. (See "Initiation of breastfeeding", section on 'Optimize mechanics of feeding'.)

High rates of milk flow may interfere with breastfeeding by less mature infants because their suck-swallow-breathe coordination is not fully developed. For these infants, the rate of milk flow can be reduced for the initial breastfeeding sessions by fully or partially expressing milk from the mother's breasts before each session [18,23]. The reduced milk flow allows the infant to feed without a need for mature suck-swallow-breathe coordination or prolonged closure of the airway for swallowing. As the infant matures and demonstrates a more mature sucking pattern, the infant can handle a greater milk flow rate and the mother no longer needs to express milk prior to the feeding.

There is no evidence that initiating oral feedings with a bottle is either necessary or advantageous. In crossover studies, premature infants exhibited more stable oxygenation and body temperature, but less milk transfer, during breastfeeding compared with bottle feeding [24-26]. The more stable respiratory patterns associated with breastfeeding, including oxygenation, may be a result of the slower rate of milk flow during breastfeeding compared with bottle feeding. In a study of preterm infants born at 32 weeks gestation, direct breastfeeding took longer than bottle feeding, but there was no difference in milk intake and resting energy expenditure [27]. Direct breastfeeding, especially the first oral feeding, also appears to increase the likelihood of continued breastfeeding at discharge [28].

Assessment of milk intake — In the initial stages of breastfeeding the preterm infant, clinical assessment of feeding behaviors, including observation of swallowing activity, is not a reliable tool for measuring milk transfer [29-31]. Milk intake is best assessed by weighing the infant before and after breastfeeding.

Test weighing — The most reliable and accurate measurement of milk intake is test weighing based upon the difference in weight before and after a feed, using a precise electronic scale [32]. These devices weigh to the nearest 2 g, automatically calculate milk intake from the pre-feed and post-feed weights, and have been demonstrated to measure milk intake accurately for term and preterm infants [33]; they can be rented for home use after discharge.

●Indications – Test weighing protocols should be developed for each institution and may vary depending on the clinical goal, such as evaluating the infant's ability to transfer milk, need for supplemental feedings, and preparing for infant discharge. As examples:

•For an infant with marginal suckling ability whose mother has a sufficient pumped milk volume, test weighing can determine if the milk transfer is adequate. In this case, test weighing for some feeds helps to monitor the infant's ability to transfer milk and may guide compensatory strategies. Poor milk intake, as measured by test weights, should also be an indication for the mother to pump after the breastfeeding attempt in order to ensure adequate stimulation for continued milk production. (See 'Problems with milk production' below.)

•During the early transitional phase to direct breastfeeding, performing test weighing for all breastfeeds provides the mother and staff with an objective measure to track the infant's progress and determine the need for facilitative and/or compensatory strategies (ie, modify infant positioning, use a nipple shield, etc). Once breastfeeding is more established, test weighing can be done less frequently. At this stage, the mother may prefer to estimate the adequacy of the feed based on her observations of the infant's feeding behaviors, but test weighing is still the only accurate measure of intake.

•During the days before NICU discharge, infants are typically transitioned from scheduled feedings to a cue-based feeding schedule, which helps them develop cue-based feeding behavior. Because preterm infants do not demonstrate predictable feeding cues until close to term-corrected age, cue-based feeding could lead to inadequate intake [16,29]. Test weighing permits a modified cue-based feeding schedule while safeguarding against slow weight gain and/or dehydration. (See 'Modified demand-feeding schedule' below.)

●Protocol – For accurate measurement, the infant should be weighed before and after a feed using the following procedure [34]:

•Place the scale on a level, stable surface, avoiding drafts

•Ensure that no part of the scale pan is touched or in contact with another surface during the weighing procedure and that clothing/blankets are not draped over the sides of the scale

•Ensure that any items of clothing, blankets, and any contents of the bowel or bladder included in the pre-feed weight are also included in the post-feed weight (ie, do not change the diaper between the two weight checks).

•Avoid any tension on any connected leads and/or tubing and maintain consistent positioning of these

•The volume of milk ingested equals the difference between the pre- and post-feeding weight

●Efficacy – Using the standard protocol described above, the difference between pre- and post-feeding weights is an accurate measure of the feeding volume [35]. Benefits of test weighing were demonstrated in a comparison study of two NICUs, in which exclusive breastfeeding was attained at an earlier postmenstrual age in an NICU that used test weighing to measure milk intake compared with an NICU that used clinical observation to estimate milk intake [36]. In another study, a clinical breastfeeding assessment tool was able to identify feeds in which no milk was transferred but was unable to distinguish whether one-half versus the full prescribed volume was taken [37]. These findings suggest that clinical indices may underestimate milk intake, especially during the critical transitional phase of breastfeeding in the preterm infant.

Clinical assessments — As breastfeeding progresses, adequacy of milk intake can be monitored by maternal/staff observations of improved infant feeding behaviors and daily weighing of the infant. If weight gain is suboptimal, breastfeeding effectiveness should be reevaluated, including test weighing to assess milk intake.

Approach to inadequate milk intake — The cause of insufficient milk intake as measured by test weighing is likely due to poor milk transfer secondary to the preterm infant's feeding behavior. However, inadequate milk production may also be a cause of poor milk intake that can be identified by reviewing with the mother her milk expression schedule and pumped milk volumes, which also allows for timely intervention.

Problems with milk production — Mothers who deliver prematurely may have difficulty in establishing an adequate milk supply, which is typically defined by milk volume >500 mL/day by two weeks postpartum. The most likely cause of insufficient milk volume is less than optimal breast stimulation during the critical "coming-to-volume" phase in the first two weeks post-birth. Early (within one to six hours of delivery) and frequent milk expression (every three to four hours or more) with a hospital-grade electric breast pump in the first two weeks is critical to achieve a 500 mL per day target milk volume [38]. Incomplete maturation of the mammary gland may also contribute to problems with milk production, although the breasts are usually able to secrete milk by 20 to 25 weeks gestation.

Strategies to increase/maintain milk volume for breastfeeding include:

●Identify risk factors associated with decreased milk production, including previous breast surgery (primarily breast reduction surgery), maternal medications (eg, pseudoephedrine), endocrine disorders, and other maternal conditions (eg, obesity, preeclampsia, polycystic ovary syndrome, hypothyroidism [38]) (table 1). (See "Breastfeeding: Parental education and support", section on 'Initial assessment'.)

●Frequent emptying of the breast to stimulate milk production, ideally every three hours with no longer than five hours between pumping at night. The optimal approach is to use a double electric pump, combined with breast massage and hand expression of milk. Of note, suction from the breast pump or infant is needed to elicit the prolactin response that stimulates continued milk production; hand expression is not sufficient [38]. For pump-dependent mothers, it is important to ensure that the pump flange size is a good fit to optimize milk flow and more complete breast emptying. (See "Breast milk expression for the preterm infant", section on 'Ensure breast emptying'.)

●Other strategies include tactile nipple stimulation, skin-to-skin contact, and, possibly, the use of galactagogues (in selected patients). These interventions are discussed in greater detail separately. (See "Breast milk expression for the preterm infant", section on 'Specific measures to optimize milk production'.)

Problems with milk transfer — Insufficient milk transfer during direct breastfeeding is defined as the inability of the infant to ingest an adequate milk volume (as indicated by test weighing) when the mother's milk supply is known to be adequate (as indicated by daily expressed milk volumes).

The main causes of insufficient milk transfer are:

●Immature infant suckling – Suckling immaturity is the most common cause of ineffective milk transfer in preterm infants [15,29,30]. These infants tend to generate by low suction pressures during suckling and use short, irregular sucking bursts that may result in poor milk transfer and ineffective oral feeding [39]. Despite these immature feeding characteristics, some preterm infants can transfer sufficient milk volumes for adequate growth as early as 32 weeks postmenstrual age; the median age for achieving this milestone is approximately 35 weeks [13].

●Failure to trigger the milk ejection reflex – Another relatively common cause of insufficient milk transfer is difficulty eliciting the milk-ejection reflex during early breastfeeding attempts. This problem may be related to antecedent use of a mechanical breast pump, which exerts higher suction pressure than the infant and conditions the breast to the higher suction pressure. Hand expression/breast massage and/or briefly pumping to stimulate milk ejection just prior to the breastfeed is an effective strategy. As the infant's sucking pattern matures, this problem should improve as breastfeeding progresses (usually as the infant nears term age).

●Difficulty sustaining latch – Because of their weak sucking pressures (-2.5 to -15 mmHg), premature infants may have difficulty maintaining attachment to the breast [23]. This issue can be addressed by using a thin-walled nipple shield, which facilitates sustained breast attachment [40,41]. After the infant begins to suck, a vacuum is created in the shield chamber and the negative pressure facilitates milk transfer. This results in an accumulation of milk within the shield chamber when the infant pauses between sucking episodes. When the infant resumes suckling, the pooled milk flows despite the low pressure generated by the infant.

The efficacy of a nipple shield intervention was illustrated in a study of 34 preterm infants in which use of a nipple shield resulted in greater milk transfer compared with the previous feeding without a shield (18.4 versus 3.9 mL) [40]. The infant's tongue movement pattern is not altered by use of a nipple shield [39].

Mothers generally like the nipple shield because it often is associated with the first breastfeeding experience in which the infant remains awake, sucks eagerly, and consumes measurable volumes of milk. Data are somewhat conflicting regarding the effects of continued nipple shield use. One study found no effect on age at which exclusive breastfeeding was achieved in one analysis [14], another reported a negative effect on this milestone in another analysis (49 percent achieving exclusive breastfeeding with a nipple shield and 66 percent without) [42], and another found positive effects of continued use of the nipple shield after hospital discharge on duration of breastfeeding [40]. In the absence of definitive data, it is reasonable to individualize the use of a nipple shield and to encourage the mother to try breastfeeding with and without the nipple shield as the infant matures.

Other feeding techniques, such as cup or finger feedings, are sometimes used as an alternative to the nipple shield. However, there is little evidence that these strategies improve milk transfer or the duration of breastfeeding after discharge [43].

Transition to full breastfeeding — The timing of the transition to exclusive breastfeeding prior to hospital discharge depends upon the availability of the mother and feeding ability of the infant. Clinical staff and NICU policies can support the transition by encouraging the mother to participate in feeding and other daily care tasks, which enhance maternal self-efficacy and maternal-infant attachment. These maternal attributes also help to develop a positive feeding relationship beyond the NICU stay. Teaching parents to recognize feeding cues and co-regulate feedings with the infant also helps to improve feeding outcomes [44,45].

Modified demand-feeding schedule

●Rationale – Preterm infants do not demonstrate predictable demand-feeding behaviors until close to term (corrected age) [15,29]. As a result, a modified demand-feeding schedule is most appropriate for these infants. This approach requires that the parent be present to recognize infant feeding cues and co-regulate feedings in response to these behaviors, while setting a 24-hour minimal milk intake target as a safeguard against slow weight gain and/or dehydration. Limited evidence from a systematic review suggests that modified demand-feeding regimens were associated with an earlier attainment of full oral feedings compared with scheduled feedings [46].

●Implementation – To implement a modified demand-feeding schedule, the 24-hour minimal milk intake is calculated based on the infant's estimated caloric needs. This target volume is subdivided into three dosed feedings to be administered in each eight-hour period (or four dosed feedings over a six-hour period). During this time period, the mother breastfeeds when the infant shows feeding cues (ie, feed on demand) and monitors the infant's actual milk intake at each feed using test weighing (see 'Test weighing' above). If the infant does not consume the minimum volume over the designated six- or eight-hour period, extra milk is provided at the end of the time interval to ensure adequate caloric intake and prevent dehydration. The extra milk is given by bottle, cup, or nasogastric tube (if in place). (See 'Supplementary feeds' below.)

As an example, if an infant weighing 1700 g requires a minimum of 300 mL of milk per day, the target intake is 100 mL every eight hours. The infant is allowed to demand-feed but must receive the prescribed 100 mL within the eight-hour period. This allows the infant the opportunity to self-regulate sleep and feeding.

This method allows the mother to breastfeed on demand during the hours that she is with her infant in the hospital. It also provides the clinician with the necessary information regarding whether or not the infant can maintain an adequate intake solely by breastfeeding and modify the infant's feeding regimen in preparation for discharge. In addition, it allows the mother to observe the feeding cues, feeding patterns, and sleep habits of her infant in a controlled environment under the guidance of the NICU staff.

When implementing demand feeding, the mother should pump after each breastfeeding session to protect her milk supply. Expressing this residual milk is important to ensure continued optimal milk production since the preterm infant is often unable to transfer the available milk in the breasts. In addition, the pumped milk can be stored for use in the supplemental feedings, when needed.

Supplementary feeds — During the transition from partial to full breastfeeding, additional human milk feedings will be required based on test weights. Alternative feeding methods for supplemental feedings include tube, bottle, and cup. The most common method of supplemental feedings is by bottle once the infant is taking all feedings orally. However, cup feeding has been shown to be a safe method [47]. Moreover, cup feeding is associated with more mature breastfeeding behaviors and higher rates of exclusive breastfeeding after discharge compared with bottle feeding [48-51]. However, parents and staff must be trained on cup feeding techniques to ensure safety and efficiency.

Vitamin D and iron supplements — Vitamin D and iron supplementation are recommended by the American Academy of Pediatrics in preterm infants who are breastfed [52].

●Vitamin D – When a preterm infant tolerates full enteral feeds, the recommended intake for vitamin D is approximately 400 international units daily (up to a maximum of 1000 international units daily) [53]. This is consistent with recommendations for term breastfed infants, for whom vitamin D supplementation (400 international units daily) is recommended starting in the first week of life. (See "Management of bone health in preterm infants", section on 'Vitamin D requirements'.)

●Iron – In breastfed preterm or low birth weight infants, iron supplementation (2 to 4 mg/kg/day of elemental iron, maximum 15 mg) in the form of ferrous sulfate is recommended starting at two weeks of age and is continued until 12 months of age or until adequate iron from dietary sources is assured when solid foods are introduced. (See "Iron deficiency in infants and children <12 years: Screening, prevention, clinical manifestations, and diagnosis", section on 'Dietary recommendations'.)

Nearing hospital discharge — For discharge planning, milk supply and transfer continue to be the two main issues:

●Milk supply – The most important factor for mothers who will be breastfeeding a preterm infant at home is maintaining a milk supply that exceeds the baby's requirements at discharge [9,54,55]. An adequate milk supply results in a sufficient milk flow rate that can compensate for the infant's immature suckling. The mother's milk supply should be evaluated periodically over the course of the NICU stay by measuring pumped milk volume and/or infant intake in test weighing. If there is concern that the milk supply may be insufficient, steps should be taken to increase milk production. (See 'Problems with milk production' above.)

After discharge, mothers will need to continue to express milk after some or most feedings to remove residual milk until their infant is feeding more effectively and consistently at the breast. Although mothers are anxious to reduce or eliminate the need to pump after discharge, it is important to include these instructions in the post-discharge feeding plan. (See 'Problems with milk production' above and "Breast milk expression for the preterm infant", section on 'Specific measures to optimize milk production'.)

●Milk transfer – As discussed above, the use of nipple shields facilitates milk transfer and can be used after discharge in preterm infants who have immature suckling and difficulty in milk transfer. Anticipatory guidance should be provided on how to wean from the nipple shield as breastfeeding progresses. Strategies for weaning from the shield include: (1) beginning the feed with the shield in place and then removing and reattaching the infant to the breast to complete the feed, or (2) beginning the feed without the shield when the infant is more alert and then reapplying the shield toward the end of the feeding. We have found that most preterm infants are more likely to wean from the nipple shield when they reach term gestational age. (See 'Problems with milk transfer' above.)

Infants who are unable to take sufficient feeds orally may require some tube feeding after discharge. This requires training of the mother or caregivers to do this safely as well as close monitoring of the infant's progress. In one study, earlier hospital discharge with tube feeding was feasible and was associated with an increased duration of breastfeeding compared with infants who were discharged later, after achieving full oral feeds [56]. (See "Breast milk expression for the preterm infant".)

LATE PRETERM INFANTS — Late preterm infants (born between 34 weeks and 36 weeks and 6 days gestation) require specific attention for discharge planning and follow-up. Since many of these infants are discharged with their mothers following the maternity hospital stay or a short neonatal intensive care unit (NICU) stay, they may have had only limited clinical lactation support. Therefore, robust discharge and post-discharge planning is necessary to monitor the adequacy of direct breastfeeding progression and maternal milk production [6,7,57,58]. (See "Late preterm infants", section on 'Breastfeeding difficulties'.)

In addition to the management routinely used to promote breastfeeding in all infants, interventions during the birth hospitalization that specifically address breastfeeding issues in late premature infants include:

●Feeding assessment – The feeding assessment includes direct observation of the infant's latch to the breast; suck/swallow/breathing patterns; and behavior before, during, and after breastfeeding (see "Initiation of breastfeeding", section on 'Principles of breastfeeding'). Based on these observations, a plan should be developed in collaboration with the mother on the progression of at-breast feedings and the need for extra milk feedings. This may include test weighing procedures as a strategy to use post-discharge to monitor milk transfer and manage extra milk feedings. (See 'Test weighing' above.)

●Protecting maternal milk production – Mothers of late preterm infants must build their milk production concurrently with breastfeeding initiation and progression, unlike mothers of smaller preterm infants who have established their milk volumes during the NICU stay. One approach to promote milk volume is to use the "triple feeding" technique during the first two weeks of lactation, which is a critical period for establishing milk production. Triple feeding consists of direct breastfeeding, followed by use of an electric breast pump, then feeding the infant with the expressed breast milk. This technique promotes milk production by maximizing breast stimulation and removing residual milk in the breast. However, this regimen can be exhausting for mothers. Mothers who are struggling with time constraints of "triple feeding" in an infant with immature skills at the breast may modify this technique by occasionally skipping a direct breastfeed and substituting pumping and bottle feeding. Although this approach is not ideal, it may allow a time-strapped mother to maintain lactation until the baby can exclusively feed at the breast.

An alternative plan is to set a target volume for each eight-hour period and give supplementary feeds if the infant does not breastfeed well, similar to the modified demand-feeding approach described above [57], with the caveat that not pumping after a suboptimal breastfeed risks milk supply. (See 'Modified demand-feeding schedule' above.)

●Facilitative/compensatory strategies to improve breastfeeding – A variety of devices and techniques can be used to improve milk transfer during breastfeeding. These include modifying the infant's position to optimize attachment, using nipple shields to facilitate attachment to the breast and improve milk transfer, and providing at-breast supplementation with supply line feeder to entice latch and continued sucking. (See 'Problems with milk transfer' above.)

●Extra breast milk feedings – When supplemental feedings are indicated for late preterm infants (eg, as part of a modified demand-feeding schedule), the optimal choice is mother's own milk. When the mother's own milk is not available, banked human milk or commercial infant formula can be used. Indications for supplemental feedings include:

•Documented low maternal milk supply

•Excessive infant weight loss (eg, as measured by the newborn weight loss tool [NEWT] nomogram or more than 7 to 10 percent of their birth weight, although evidence-based guidelines are lacking in this population)

•Signs of dehydration (eg, decreased urine output or abnormal electrolytes if measured)

(See "Initiation of breastfeeding", section on 'When and how to supplement with formula'.)

DISCHARGE PLANNING — Discharge breastfeeding planning for the preterm infant includes these steps:

●Clinical assessment of breastfeeding:

•Assess direct breastfeeding, observing for an effective latch, maternal comfort, and signs of milk transfer. Educate the parent to recognize infant feeding cues as an optimal sign to initiate feedings. (See 'Clinical assessments' above and "Initiation of breastfeeding", section on 'Optimize mechanics of feeding'.)

•Determine the need for using test weighing at home to monitor milk transfer during breastfeeding. (See 'Test weighing' above.)

•Have the mother and other caregivers practice a safe and effective alternative feeding method that can be used to deliver supplemental feedings as needed. This may include use of a bottle, cup, or tube feeds. (See 'Supplementary feeds' above.)

●Protect maternal milk production:

•The first two weeks post-birth is a critical period for establishing lactation and an adequate milk supply.

•Instruct the mother to pump to remove residual milk from her breasts after breastfeeding sessions or when she is separated from the infant. For mothers with an established milk supply, the mother can gradually wean from additional milk expression as the infant progresses to exclusive breastfeeding. (See 'Late preterm infants' above.)

•Provide the mother with instructions on proper breast milk storage at home in anticipation for the need of supplemental feedings.

●Have a clear feeding plan:

•Determine the most effective feeding plan that meets the mother's and infant's abilities and needs.

•Provide specific guidelines on optimal feeding frequency, number of supplemental feedings if indicated, and resources for post-discharge breastfeeding support.

•If the infant has not fully transitioned to direct breastfeeding or has marginal intake, recommend a plan for the mother to advance breastfeeding and protect her milk supply (triple feeding or a modified demand-feeding schedule, as described above). This approach ensures adequate intake while reducing the mother's workload and fatigue. (See 'Transition to full breastfeeding' above.)

●Arrange close follow-up:

•Schedule a follow-up appointment within 48 hours of hospital discharge to check the infant's weight and feeding adequacy and evaluate for signs of dehydration or jaundice.

POST-DISCHARGE — Preterm infants remain at risk for inadequate milk intake by exclusive breastfeeding until approximately term-corrected age [30]. Clinical indicators of milk intake used in term infants (ie, breastfeeding behaviors [signs of satiety], wet diapers, frequency of stooling, and sleep patterns) are not reliable or accurate markers in preterm infants. Test weighing remains the most accurate assessment of milk intake. (See 'Test weighing' above.)

As a result, it is often advisable to perform serial weight measurements after hospital discharge, which may include test weighing before and after each feed or daily weights. An ideal tool is a specially designed, battery-operated scale that parents can rent for this purpose. This scale can be a useful adjunct to breastfeeding management for mothers and preterm infants during the first week or two after discharge [59]. Mothers should be introduced to the proper use of the scale during the days prior to discharge. (See 'Test weighing' above.)

Mothers should be encouraged to continue the breastfeeding strategies used in the hospital until their infants have demonstrated an acceptable pattern of growth (ie, 20 g/day weight gain) for at least one or two weeks. These may include use of a breast pump after feeding to ensure emptying of the breast, nipple shields, and in-home weighing. In addition, parents should be referred to community-based lactation support programs and/or resources. (See "Breastfeeding: Parental education and support".)

The growth of the discharged preterm infant needs to be carefully monitored by the primary care provider. Growth parameters include the infant's weight, length, and head circumference and should be monitored on a weekly to biweekly basis for the first four to six weeks after hospital discharge. (See "Growth management in preterm infants", section on 'After discharge'.)

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Breastfeeding and infant nutrition".)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

●Basics topics (see "Patient education: Pumping and storing breast milk (The Basics)" and "Patient education: Deciding to breastfeed (The Basics)" and "Patient education: Breastfeeding (The Basics)" and "Patient education: Common breastfeeding problems (The Basics)" and "Patient education: What to expect in the NICU (The Basics)")

●Beyond the Basics topics (see "Patient education: Pumping breast milk (Beyond the Basics)" and "Patient education: Health and nutrition during breastfeeding (Beyond the Basics)" and "Patient education: Breastfeeding guide (Beyond the Basics)" and "Patient education: Common breastfeeding problems (Beyond the Basics)")

SUMMARY AND RECOMMENDATIONS

●Approach in preterm infants <34 weeks gestation – Implementation of breastfeeding for the preterm infants <34 weeks gestation involves (see 'Breastfeeding initiation for preterm infants' above):

•Assessing readiness – Breastfeeding depends upon the development of sufficient oral skills for successful milk transfer from the breast. The timing of development of sufficient suckling ability varies among preterm infants. Although oral feedings often are initiated at approximately 33 to 34 postmenstrual weeks, some infants can successfully initiate breastfeeding as early as 28 weeks postmenstrual age. (See 'Readiness' above.)

•Initiating breastfeeding – We suggest using the infant's cues (ie, oral behaviors such as nonnutritive sucking [sucking on a pacifier] and rooting) rather than relying on postmenstrual age to determine when breastfeeding can be initiated (Grade 2C). In some cases, the preterm infant with poorly developed suck-swallow-breathe coordination can only handle a small volume of milk. As the infant's oral skills mature and his/her ability to handle greater milk flow rates increase, breastfeeding can be advanced. (See 'Initiation of breastfeeding' above.)

•Assessing milk intake – During the hospitalization, the progression of breastfeeding is monitored by assessing milk intake. The most accurate measurement of milk intake is test weighing (ie, the difference in weight before and after each feeding). (See 'Assessment of milk intake' above.)

•Addressing causes of inadequate milk intake – Insufficient milk intake may be caused by inadequate milk production and/or failure of milk transfer. Milk production is generally inadequate if pumped daily milk volume is <500 mL by two weeks postpartum. Milk transfer is assessed by test weighing of the infant before and after breastfeeding. (See 'Approach to inadequate milk intake' above.)

•Transition to full breastfeeding – When the infant demonstrates the ability to consume all feeds orally, we suggest a modified demand-feeding schedule rather than scheduled feeding or ad libitum-demand feeding (Grade 2C). In the modified demand-feeding schedule, if the infant does not take the target volume of milk intake via direct breastfeeding, they are given supplementary feeds of breast milk (with or without fortifier) by bottle, cup, or feeding tube. This approach allows mothers to recognize infant feeding cues and co-regulate feedings in response to these behaviors, while retaining a safeguard against slow weight gain and/or dehydration. (See 'Transition to full breastfeeding' above.)

●Late preterm neonates (34 through 36 completed weeks gestation) – Although late preterm infants are often able to be fully breastfed, they may experience difficulty in establishing successful breastfeeding because their oro-buccal coordination and swallowing mechanisms may not be fully matured, risking maternal milk supply due to inadequate stimulation. These mothers and infants require expert instruction and close observation during the early phases of breastfeeding, and sometimes interventions similar to those used for more preterm infants. (See 'Late preterm infants' above.)

●Discharge planning and follow-up – Preterm and late preterm infants who are exclusively breastfed remain at risk for inadequate milk intake until approximately term-corrected age. Care after discharge includes close growth monitoring, continuation of the breastfeeding strategies used in the hospital until an acceptable growth trajectory is reached, and referral to lactation support programs and/or resources if needed. (See 'Discharge planning' above and 'Post-discharge' above.)

●Vitamin D and iron supplementation – Preterm and late preterm infants who are breastfed or fed with expressed breast milk require supplements of vitamin D and iron. Oral vitamin D supplementation is typically initiated when the infant is tolerating full enteral feeds. Iron supplementation is typically initiated by two weeks of age. (See 'Vitamin D and iron supplements' above and "Management of bone health in preterm infants", section on 'Vitamin D requirements' and "Iron deficiency in infants and children <12 years: Screening, prevention, clinical manifestations, and diagnosis", section on 'Dietary recommendations'.)