Home > Pregnancy and birth: Expressing breast...

PubMed Health. A service of the National Library of Medicine, National Institutes of Health.

Informed Health Online [Internet]. Cologne, Germany: Institute for Quality and Efficiency in Health Care (IQWiG); 2006-.

Informed Health Online [Internet].

Pregnancy and birth: Expressing breast milk: Are some methods better than others?

Last Update: September 24, 2014; Next update: 2017.

The method a woman chooses will mostly depend on her personal preferences. Women could possibly express more milk if they used an electric pump rather than expressing by hand. Doing relaxation exercises while expressing milk might also help.

There are many reasons why breastfeeding is important for babies – for example, the closeness it brings between the mother and her child, and because it lowers the risk of some infectious diseases in infants. The World Health Organization recommends exclusively breastfeeding in the first six months after birth, and then continuing to breastfeed the child while starting to introduce solid foods too.

Sometimes, though, breastfeeding is not possible – perhaps because the baby is ill, or was born prematurely and is too weak to suck the milk out. A mother may not be able to breastfeed because her nipples are too sore, for instance, or because she has to go to work or keep an appointment.

In these situations, she can express milk for the baby to drink either straight away or at a later time out of a bottle. If a mother’s breasts are engorged (painfully full and hard) or she has mastitis (a breast infection), expressing milk can relieve the discomfort. Milk can either be expressed by hand or using a breast pump. There are many different types of breast pumps: for one or both breasts, manual (hand) pumps, battery-operated and electric pumps. The type you use will depend on which one you feel most comfortable with.

Breast pumps and expressing by hand

Women can express milk by hand using specific hand movements to stimulate the flow of milk in their breasts. No equipment is needed, other than something to collect the milk in. You can try it yourself, or ask a midwife, lactation consultant or an experienced mother to show you how to do it. Most women will need a bit of time and practice to get the hang of it.

A breast pump creates suction pressure on the outside of the nipple, which pulls or “sucks” milk out of the breast. Manual pumps are the simplest kind of breast pump. Here the suction is created by operating a bulb, lever or balloon with your hand. A bit of practice is often needed to get the hang of using these too. Manual pumps can sometimes be difficult to use. Some can be operated using just one hand, so you could theoretically use two at the same time.

Electric pumps of various sizes are also an option. Some are battery-operated. It is usually possible to regulate the pump’s suction strength. Some also pump at intervals to copy the rhythmic sucking behavior of a baby.

Many electric pumps can be used on both breasts at the same time. They are quite a bit more expensive than manual pumps. In Germany, you can rent one at a fairly low cost from a midwife, pharmacy or medical supply store. If you need it for medical reasons, a doctor can give you a prescription for the rental pump.

It is not always easy to use the pump at first

All breast pumps can have unpleasant side effects: some women, for example, find that their nipples become sore and irritated. Here it is helpful to try out several types of pump with different attachments. Some women find expressing milk stressful and awkward, or they may have problems operating the pump. As a result, less milk may come out or they might give up altogether. If you are having difficulties, talk to an experienced friend, midwife or lactation consultant.

Whichever method you use, it is very important that you wash your hands before expressing milk, and always thoroughly disinfect, boil or steam-clean the pump and accessories to kill any germs. It is also important to cool the milk or freeze it straight away if you do not want to give it to your baby immediately, to keep it germ-free. According to the German National Breastfeeding Commission, breast milk should only be kept in the refrigerator for up to three days, and should only be kept in the freezer for up to six months. When refrigerating or freezing milk, it is important to label the milk container with the date the milk was expressed, so you can see how old it is.

Research results

Researchers from the Cochrane Collaboration – an international research network – wanted to find out which method of expressing breast milk is the most effective, the safest and the most comfortable. They looked for studies comparing different methods of expressing breast milk. They found 23 studies in total, but only ten of them – involving a total of 630 participants – provided suitable data. These studies were carried out in the U.S., England, Brazil, Malaysia, Kenya and Nigeria. The participants were randomly assigned to groups that used different methods of expressing milk. In more than half of the ten studies, the participants were mothers who had recently given birth and whose babies were being given expressed breast milk because they had been born prematurely, were underweight or ill.


Research suggests that bacterial contamination is quite rare in expressed milk, and none of the methods was more likely to cause bacterial contamination either. There is no evidence that any of these methods are associated with more breast or nipple pain.

Amount of milk

Women who used an electric pump on both breasts obtained more milk than women who expressed milk by hand. But the studies did not give any information about which exact technique the women used when expressing by hand, or whether they had been given good instructions – both of which can greatly influence the outcome. Also, the difference between the amounts of milk expressed was too small to be truly significant. Different women produce different amounts of milk anyway, and not very many women took part in the studies, so it is not clear whether the difference in the amount of milk expressed really depends on the method used. The researchers did not find any significant difference between the amounts of milk expressed using electric pumps and manual pumps.


One other thing the researchers were interested in was how long it takes to get a certain amount of milk using the different methods. Women who used an electric pump needed less time to get the same amount of milk than women using a manual pump. It is worth mentioning that when women in the studies used electric pumps, they usually used them on both breasts, which was not possible with the manual pumps that were used. But, as the Cochrane researchers pointed out, other studies have found that many women feel uncomfortable using a pump on both breasts at the same time.

Relaxation may make it easier

One study involving 71 participants looked at the effect of audio recordings of relaxation exercises on women while expressing milk. The study concluded that women who relaxed in this way while expressing milk obtained more milk during each session than women in a comparison group who did not listen to the audio recording. No other relaxation techniques or other supportive measures such as breast massages or essential oils were studied.

Unanswered questions

All of the studies were very small and only tested a few pumps, so no truly reliable conclusions can be drawn from them. Also, most of the research was funded by the manufacturers of the pumps that were tested. More independent research is needed to tell which method is the safest, the most effective and the most comfortable for women.


  • Becker GE, Cooney F, Smith HA. Methods of milk expression for lactating women. Cochrane Database Syst Rev 2011; (12): CD006170. [PubMed: 22161398]
  • Bundesinstitut für Risikobewertung (BfR). Sammlung, Aufbewahrung und Umgang mit abgepumpter Muttermilch für das eigene Kind im Krankenhaus und zu Hause. Empfehlung der Nationalen Stillkommission vom 2. März 1998.
  • IQWiG health information is written with the aim of helping people understand the advantages and disadvantages of the main treatment options and health care services.

    Because IQWiG is a German institute, some of the information provided here is specific to the German health care system. The suitability of any of the described options in an individual case can be determined by talking to a doctor. We do not offer individual consultations.

    Our information is based on the results of good-quality studies. It is written by a team of health care professionals, scientists and editors, and reviewed by external experts. You can find a detailed description of how our health information is produced and updated in our methods.

© IQWiG (Institute for Quality and Efficiency in Health Care)

PubMed Health Blog...

read all...

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...