BREAST PUMP OVERVIEW

A breast pump is a device that allows a woman to express breast milk from the breasts when it is not possible to breastfeed her infant directly. Many women choose to use a breast pump so that they can continue to provide breast milk while working or if their infant is hospitalized. However, it is not necessary for all women who breastfeed to purchase or use a breast pump.

This topic review discusses the use of breast pumps and breast milk storage and preparation. Other topics about breastfeeding are available separately. Additional breastfeeding topics are available separately. (See "Patient information: Common breastfeeding problems" and "Patient information: Breastfeeding basics" and "Patient information: Maternal health and nutrition during breastfeeding" and "Patient information: Deciding to breastfeed".)

CHOOSING A PUMP

There are a wide variety and quality of breast pumps available, each of which varies in cost, quality, and efficiency; the optimal pump depends upon your needs and how frequently the pump will be used. No one pump is best for every woman. In most situations, you should wait to buy a pump until after your infant is born; this will allow you to determine your and your infant's individual needs.

Some of the most common reasons women use a breast pump include the following:

• To stimulate your milk production when you are unable to nurse your infant after birth (eg, if your infant is in the hospital)
• To maintain your milk supply when you are away from your infant (eg, after returning to work)
• To provide your baby with your breast milk

Hospital grade electric breast pump — A hospital grade electric breast pump is recommended for women who must initiate and maintain their milk production for extended periods of time, such as those with a premature or hospitalized infant who cannot nurse immediately after delivery [1]. This is the most efficient, easiest, and fastest type of pump, and is the most effective way to maintain an adequate milk supply for an infant's full nutritional needs [2]. Although most women prefer to pump both breasts at the same time (double pump), this pump can be used to pump one breast at a time [3].

The amount of time it takes to empty both breasts will vary depending upon the woman's experience with the pump, although it generally takes about 10 to 15 minutes after let-down has occurred. A hospital grade pump can be safely used by more than one woman in a hospital and may be rented for home use. These pumps are larger and heavier that other pumps, and therefore may not be as portable. Some commercial health insurance plans cover the cost of purchasing or renting a hospital grade breast pump.

Personal electric pump — A smaller, personal electric breast pump is designed for one woman to use several times per day. These pumps are not as effective in establishing and maintaining a woman's milk supply long term (without intermittent breastfeeding). Most models allow you to pump one or two breasts at a time. The life expectancy of these pumps is generally about one year, depending upon how frequently the pump is used.

Most of the high quality personal pumps are self-contained in a carrying case (as a backpack or shoulder bag) that includes the motor, supplies, and in some cases, a cooler for storing milk. The pump and related equipment are small and light enough to carry on a daily basis and can pump one or both breasts. These pumps work well for the working mother or when traveling. These pumps are intended for use by only one woman; sharing or re-selling of a personal pump is not recommended.

Single-sided pump — If you want to pump occasionally so that you can leave your baby with a caregiver for a few hours, a single-sided breast pump may be adequate [4]. Single pumps are powered by hand, batteries, or electricity. Single breast pumps are not recommended if you need to maintain your milk supply while working or for a premature infant, but are adequate for occasional use. Pumping both breasts with a single-sided pump takes about 20 to 30 minutes.

HOW TO PUMP

There are a wide variety of breast pumps, each of which has specific instructions for use. The following are general recommendations for use of a breast pump.

• Wash your hands with soap and water before pumping. It is not necessary to wash the breasts or nipples [5].
• Ensure that the pump pieces and milk collection containers are clean. Washing with hot soapy water is sufficient; it is not necessary to sterilize the pump or bottles when pumping for a healthy infant. Do not wash the pump tubing because it cannot be dried easily. If moisture or milk is noted in the tubing, contact the manufacturer. It may be necessary to purchase new tubing.
• Most women prefer to sit while pumping. For electric pumps, set the pump's suction strength to a comfortable level. Pumping should not hurt, even if you have sore or painful nipples. On some pump models, the cycling speed (the number of suction cycles per minute) can be set based on personal preference; some women start with a rapid cycle speed then slow the speed after their milk begins to flow in a steady stream (see 'Let-down' below).
• Be sure that the flanges (the cone-shaped pieces that fit over the breasts and nipples) are the appropriate size. When pumping, the nipples should not rub against the tunnels of the flanges. It may be necessary to purchase larger flanges to pump comfortably and stimulate the breasts correctly. Be sure to purchase pump parts that are the same brand as that of the pump. Parts should not be interchanged from different manufacturers.

Let-down — Let-down, also called the milk-ejection reflex, is the term used to describe what happens in the breasts when milk is released from the milk glands into the milk ducts (figure 1).

Let-down is a conditioned response usually brought on by the infant sucking at the breast and stimulating the release of the hormone oxytocin in the mother's brain. This causes cells in the breast to eject the milk. Some women experience let-down at other times, by just thinking about their baby or hearing their baby cry. For women who are dependent on the pump exclusively for breast stimulation (mothers of hospitalized infants), just seeing or hearing the breast pump may cause milk ejection.

Let-down usually occurs within the first minute or two of nursing or pumping. Some women feel a sense of heaviness or tingling in the breasts during let-down while other women cannot feel let-down at all.

Some women have difficulty with let-down while pumping. In this situation, only drops of milk are seen rather than streams of milk flowing from the nipples. Tips to promote let-down include:

• Gently massage the breasts before pumping
• Apply a warm wet cloth to the breasts before pumping
• Pump in a quiet, darkened room to avoid distractions
• Look at a picture of the baby or smell the baby's blanket

Pumping at work — Women who return to work after birth and want to continue breastfeeding will need to express their milk several times during their working hours. Pumping will allow you to maintain your milk production and provide your expressed breast milk to your infant while you are separated. Pumping on a schedule similar to their infant's feeding pattern is usually sufficient; for most women, this means pumping two to three times over eight hours. If possible, starting back to work in the middle of the work week will help to ease the transition.

It can be challenging to find the time and space to pump, especially for women who do not have a private office. You should discuss your need for a private space with your employer prior to returning to work. While a bathroom is one option, this is not ideal for pumping. It may be helpful to speak with co-workers who have returned to work and pumped to determine if a private space is available. Some employers offer a "pump room" or other private area.

The United States Center for Disease Control and Prevention has published a number of articles that address the need for support of breastfeeding women who work, citing the health as well as economic benefits of breastfeeding. These articles are available online at www.cdc.gov/breastfeeding/resources/guide.htm.

Many states have laws that require employers to support breastfeeding women; information about breastfeeding and the law can be found at La Leche League (www.llli.org/Law/LawBills.html) or at the United States Breastfeeding Committee (www.usbreastfeeding.org).

Pumping for a premature or ill infant — Women whose infants are hospitalized due to prematurity or illness following birth must rely on a breast pump to stimulate their milk production. The first few weeks following delivery are critical in establishing a milk supply that meets the needs of their infants. Several important hormonal and structural changes take place within the breast during this time.

The amount of breast stimulation during this time is critical to this process. You should pump frequently (at least eight times per day) for about 15 minutes each time until you are producing about one-half ounce per breast. Thereafter, most women find that pumping six to eight times daily and expressing for about two minutes after milk flow stops is sufficient to maintain an adequate milk supply. (See "Breast milk expression for the preterm infant".)

By day 10 after delivery, most women who are pumping eight to 10 times per day should be producing approximately 750 to 800 mL (about 25 ounces or 3 cups) of milk per day. However, milk volume varies and can range from 450 to 1200 mL (about 2 to 5 cups) per day.

If you are pumping less than 500 mL (16 ounces) per day by the 10th day, you should discuss ways to improve your milk supply with a healthcare provider or lactation consultant (see 'Finding a lactation consultant' below).

STORING BREAST MILK

Storage recommendations for breast milk are based upon a small number of studies that have examined the safety and nutritional value of breast milk that is stored under a variety of conditions. These recommendations apply to breast milk intended for full term healthy infants. Women with premature infants should discuss breast milk storage recommendations with their healthcare provider. (See "Breast milk expression for the preterm infant".)

Breast milk that is pumped may be safely stored in the refrigerator or freezer. It can even be left at room temperature (approximately 77 to 79º F or 25 to 27º C) for up to four hours [6]. This is in contrast to infant formula prepared from powder, which should not be left at room temperature after it is prepared.

Refrigerator storage — Freshly pumped breast milk can be safely stored in a standard refrigerator that maintains the temperature at 35 to 40º F (1 to 4º C) for up to eight days [7]. The coldest part of the refrigerator or freezer is best, generally towards the back and away from the door. Milk can be stored in an insulated cooler with freezer packs, not ice.

Freezer storage — Freshly pumped or refrigerated breast milk can be stored in a freezer that maintains the temperature at 0 to 4º F (-18 to -20º C) for 6 to 12 months [7]. The freezer in a mini-refrigerator does not adequately maintain this temperature range and is not recommended. Pumped milk can be stored in a deep freezer chest (-4º F or -20º C or less) for six to 12 months. The coldest part of the freezer is best, generally towards the back and away from the door.

Thawed breast milk can be safely stored in a standard refrigerator for up to 24 hours. Milk that was frozen and then thawed should not be refrozen.

Breast milk storage containers — Breast milk should be placed in a sealed, clean, glass or rigid plastic bottle designed for storing food products. Although plastic breast milk storage bags are not recommended for hospitalized infants due to the loss of some nutrients [1], plastic bags can be used to store breast milk for healthy infants.

Milk should be stored in small amounts (one to four ounces) and labeled using permanent ink and a waterproof label. The label should indicate the date the milk was pumped. Milk from different pumping sessions may be combined; the milk should be cooled in the refrigerator before it is combined. Milk that is warm or refrigerated should not be added to frozen milk. The milk should be labeled with the date the milk was pumped. The oldest milk should be used first.

If milk smells or tastes spoiled — Some expressed breast milk tastes and smells spoiled (or soapy, in some cases) within hours to days after it is pumped, even if it is stored at an appropriate temperature. A possible cause of this is a higher than normal level of an enzyme, lipase, in the breast milk. Lipase has benefits, although high levels of lipase break down the fat in breast milk, causing it to quickly taste spoiled. It is not known why some women's milk contains a high level of lipase or if the milk is safe for the baby; however, most babies refuse it.

If you notice after freezing and thawing that your milk smells spoiled or rancid, you can prevent this in the future by scalding the breast milk immediately after it is pumped to inactivate the lipase. Milk should be heated to 180º F (32º C) (when small bubbles form around the edges but the milk is not yet boiling) [8]. The milk should then be quickly cooled in a refrigerator or freezer. It is not possible to reverse the enzyme's activity in breast milk after it has been stored, thus milk that smells or tastes bad should be discarded.

Heating milk destroys some of its beneficial qualities; mothers of sick or premature infants should discuss the best way to store milk with their healthcare provider.

PREPARING PUMPED BREAST MILK FOR FEEDING

The way in which breast milk is handled during storage and prior to feeding can effect the beneficial properties of the milk.

Thawing and warming breast milk — Frozen milk can be safely thawed overnight in the refrigerator or in a warm water bath. To prepare a warm water bath, a sealed container of milk can be placed in a bowl or cup of warm water until it thaws. Thawed milk should be refrigerated until ready to use and can be safely stored for 24 hours.

Thawed or refrigerated milk may be warmed prior to feeding the infant, however some infants accept milk directly from the refrigerator. The warm water bath method can be used to warm refrigerated milk. Bottle-warming devices are also available for purchase; these should be used with care as they can quickly overheat the milk. Do not leave a bottle warmer unattended. Microwaves are not safe to use for warming or defrosting breast milk. They heat milk unevenly, potentially burning an infant's mouth and destroy some of the beneficial properties of breast milk [9].

After warming the milk, the temperature should be tested immediately before it is given to an infant; the milk should feel lukewarm or room temperature, but never hot. Milk should be gently swirled to redistribute the cream that often rises to the top during refrigeration.

There are insufficient data to know if it is safe to refrigerate and then rewarm a partially finished bottle of breast milk. Although freshly pumped breast milk has antibacterial properties, milk stored in a refrigerator for more than a day or two begins to lose this property [10-13]. Milk that smells or tastes bad should not be given to an infant (see 'If milk smells or tastes spoiled' above).

HOW MUCH MILK SHOULD I OFFER?

Many women who exclusively pump or pump while at work wonder how much breast milk their infant will need at each feeding.

The volume of breast milk your baby needs increases with age; infants who are exclusively breastfed require approximately 23 to 24 ounces of breast milk at one month of age and 24 to 30 ounces at six months of age. After six months, most infants begin to consume other foods, and less milk may be needed [14].

One way to determine how much an infant will need per feeding is to divide the infant's average intake (eg, 25 ounces) by the number of feedings per day [15]. For example, an infant who nurses eight times per day would need approximately 3 ounces per feeding (25 ounces divided by 8 feedings = 3 ounces). Thus, in this example, it would be reasonable to prepare 3 ounces of milk per feeding, with the understanding that some infants will consume less while others will want more.

Feeding breast milk with a bottle — Babies feed very differently from a bottle compared to the breast. Milk flow from a bottle is fast and the baby usually eats very quickly, sometimes by gulping. Many mothers feel that their infant drinks more milk when he or she is fed with a bottle than when nursed at the breast. It is common to worry that you will not pump enough milk to keep up with this volume.

Babies have little control over milk flow from a bottle while they have full control over milk flow from the breast. To minimize this problem, it may help to pace the baby while bottle feeding by taking frequent breaks. Slow flow bottle nipples are available and may help to minimize the differences in flow between bottle and breast feeding. A feeding should take 10 to 15 minutes or more, just like at the breast.

WHAT IF I HAVE QUESTIONS?

Your healthcare provider or your child's healthcare provider is the best source of information for questions and concerns related to breastfeeding, pumping, storage of milk, or bottle feeding your infant. Certified lactation consultants, or LCs, are available to mothers and infants at most hospitals as well as privately, and can be an invaluable resource for instruction and troubleshooting for problems. (See 'Finding a lactation consultant' below.)

WHERE TO GET MORE INFORMATION

Your healthcare provider is the best source of information for questions and concerns related to your medical problem.

This article will be updated as needed every four months on our web site (www.uptodate.com/patients).

Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.

Patient level information

Patient information: Common breastfeeding problems
Patient information: Breastfeeding basics
Patient information: Maternal health and nutrition during breastfeeding
Patient information: Deciding to breastfeed

Professional level information

Breastfeeding: Parental education and support
Common problems of breastfeeding and weaning
Infant benefits of breastfeeding
Maternal nutrition during lactation
Nutrition in pregnancy
Nutritional composition of human milk for full-term infants
Principles of medication use during lactation
Transmission of HIV through breastfeeding: Risk factors and prevention
Use of psychotropic medications in breastfeeding women
Breast milk expression for the preterm infant

The following organizations also provide reliable health information.

• National Library of Medicine

      (www.nlm.nih.gov/medlineplus/healthtopics.html)

• The Center for Disease Control and Prevention

      (www.cdc.gov/breastfeeding)

• The United States Department of Health and Human Services

      (www.4women.gov/breastfeeding)

• American Academy of Pediatrics

      (www.aap.org/healthtopics/breastfeeding.cfm)

• Working and Pumping

      (www.workandpump.com)

Finding a lactation consultant — Certified lactation consultants, or LC s, are available at most hospitals as well as privately, and can be an invaluable resource for instructions about breastfeeding, pumping, milk storage, and bottlefeeding breast milk. The websites listed below have information about finding a lactation consultant or breastfeeding counselor.

• La Leche League

      (www.lalecheleague.org)

• International Board of Lactation Consultant Examiners

      (www.iblce.com)

      phone: 703-560-7330

• International Lactation Consultant Association

      (www.ilca.org)

      phone: 919-861-5577

Finding a breast pump — Quality breast pumps, both hospital-grade and personal use, are available at various sites (retail stores, pharmacies and hospitals) for rental and purchase. The websites listed below provide information about various models and pricing.

• Medela Inc.

      (www.medela.com)

• Ameda, Inc.

      (www.ameda.com)

 [1-15]