Single or double expressing

Should I express one breast at a time or both together?

It's very important for mothers who express regularly and infrequently or never breastfeed, to express both breasts at the same time. It helps maintain their milk supply. Double expressing sends a stronger signal to the brain to create the let-down, emptying the breasts more effectively. This provides more milk and ensures ongoing production. It also increases the amount of fat in the milk, which is especially important for small premature babies. Double expressing also saves a lot of time, more than two hours a day for some mothers. It can be done with a double electric pump; two single electric pumps; one single electric pump and a hand or constant-suction pump; or one single pump and manual expression. Double manual expression uses one hand on each breast and a large bowl to catch the milk.

A) The benefits of double expressing

Most research on double or single expressing looks at pumping. Both pumping and manual expression can be single or double.

If you express only occasionally, double expressing is less critical. If you express regularly and breastfeed infrequently or never, double expressing is extremely important (Jones 2001).

1) Double expressing helps to maintain your milk supply 

Expressing both breasts at the same time instead of one at a time sends a stronger signal to the brain to create the let-down, emptying the breasts more effectively. This provides more milk and ensures ongoing milk production (Meier 2016; Prime 2012). 

Double expressing may also increase the amount of fat in the milk (Prime 2012). This may be important for premature babies.

2) Double expressing saves a lot of time

Double expressing cuts your expressing time in half. If you are expressing 7 times a day and spend 20 minutes on each breast, changing from single to double expressing would decrease your time spent to 2 hours and 20 minutes from 4 hours and 40 minutes, saving you more than 2 hours a day. This gives you more time to care for yourself and your baby.

Double pumps can also be used with hands-free systems to allow you to do other things while pumping. Some pumps are now designed to be only for hands-fee use.

B) How to double express

1) Pump options

Most mothers opt for a double electric pump if they wish to double pump, but it can also be done with:

  1. Two single electric pumps
  2. One single electric pump and one hand or constant-suction pump
  3. One single pump and manual expression

Some mothers get more milk using breast compression along with pumping. It is possible to combine breast compression and double electric pumping, if you use a hands-free system. Otherwise, you have to single express and compress the expressed breast.

2) Double manual expression

Double manual expression is done with one hand working each breast while the mother leans over a clean bowl that is large enough to catch the milk from both sides.


Jones E, Dimmock PW, Spencer SA. A randomised controlled trial to compare methods of milk expression after preterm delivery. Arch Dis Child Fetal Neonatal Ed. 2001 Sep;85(2):F91-5
Meier PP, Patel AL, Hoban R et al. Which breast pump for which mother: an evidence-based approach to individualizing breast pump technology. J Perinatol. 2016 Jul;36(7):493-9
Prime DK, Garbin CP, Hartmann PE, et al. Simultaneous Breast Expression in Breastfeeding Women Is More Efficacious Than Sequential Breast Expression. Breastfeed Med. 2012 Dec; 7(6): 442–447