Pumping Breastmilk 101

by Guest Contributor September 21, 2022

Making Milk

During pregnancy, the breast undergoes changes to produce and store milk for the newborn baby. Colostrum begins to be produced as early as 12-16 weeks during pregnancy and may begin to leak in the 3rd trimester.(1) As estrogen increases, milk ducts are developed and the secretion of prolactin is signaled. Higher progesterone levels are responsible for milk-making cells to form and grow.

Breast changes in pregnancy:

Breast may be a little sore or sensitive
Breast may feel heavier and swollen
Areola and nipple appears darker
Montgomery Tubercles develop on the areola
Veining in the breast is more visible due to increased blood flow
Ache in the armpit area - breast tissue extends into this area and is called Tail Of Spence

After your baby is born, the placenta is delivered causing progesterone and estrogen to drop. This drop signals Prolactin, the hormone responsible for making milk, to increase and for milk production to increase. Over the next 2-3 days, your milk will transition from colostrum to a more abundant volume of milk.

Keep your baby skin to skin beginning within the first hour after birth and offer your breast often. This stage of lactation is driven by hormones. Milk will be made even if milk is not being removed. How often your baby nurses and how much milk is removed each feeding is important during this stage. When milk is removed, prolactin signals more milk to be made. If breast remain full of milk, it signals to slow down the production of milk. Feeding your newborn often means more times milk is removed and more refilling of milk occurs. If your baby goes to the breast enough but is not removing sufficient milk, production is also affected. Without effective frequent milk removal, some of the cells that hold milk will begin to shut down.(2) Around 10 days postpartum, milk supply begins to be driven by demand.

When to start pumping breastmilk

Not all parents need to pump. If you will be with your baby for every feeding, you don’t need to include pumping.

It is best to wait to begin pumping until 4-6 weeks postpartum when your milk supply is well established and you are making the amount of milk needed for your baby to grow and thrive.
You’ll want to begin pumping 2-3 weeks prior to going back to work. If you need to begin pumping early for a return to work, it may be beneficial to schedule a return to work consult with your IBCLC/SACLC to help navigate pumping.

Beginning to pump too soon can signal higher milk production and lead to an oversupply. You are meant to produce the amount of milk needed for your baby . Having too much milk can make you and your baby uncomfortable.

Oversupply symptoms

Plugged ducts
Mastitis
Painful breasts
Difficulty latching
Choking and gagging during the letdown
Gassiness
Gulping during feeding
Resisting the breast
Too much or too little weight gain

How often and how much milk to pump

How often you will be away from your baby will determine your pumping and milk storing needs.

Options If you only plan to be away from your baby every once in a while:

You can use a silicone pump after your baby has nursed from both breasts. Your baby will nurse from breast #1 and then as they are nursing breast #2, you can have the silicone breast pump on Side #1 to collect milk to store. You can combine fresh milk with refrigerated milk following proper storage guidelines.(3) Only collect as much as you need to store for your baby to avoid creating an oversupply.
Add in one regular pumping session daily. Pump half an hour to an hour after your baby nurses with an electric breast pump for a small milk stash. Choose one time of day, typically the morning when milk production is higher and pump each day around the same time to store 2-4 ounces per day. Alternate which breast you pump each day. This method will gradually increase milk supply to accommodate the one pumping session per day without causing an oversupply.
Hand expression is another option you can use to remove milk. Some lactating folks get more milk from hand expression than they do from a pump. Benefits include no extra tools needed and always available.

Returning to work:

Milk production remains fairly constant from about 6 weeks until the introduction of solid foods. Your baby eats about 700 - 900 ml per 24 hours taking 60-120 ml per feeding.(4) Most parents like to store enough milk for 2 days away from the baby to have a little cushion of extra milk.

Using a double electric pump is often the most effective way to collect milk if you need to pump for returning to work. There are many options available including hands free collection cups to make pumping more convenient.

To determine how much milk you need to pump and leave for your baby while you are away from them, estimate how many times your baby nurses in 24 hours and divide that by the average amount of milk they drink in a day which varies between 700-900 ml. You can use 750 ml as an average. This will give you the amount per bottle. Plan on one bottle every 2-3 hours while away.

Example: 750 ml divided by 10 feeds per 24 hours = 75 ml

Example: 900 ml divided by 10 feeds per 24 hours = 90 ml

The amount of milk you are able to pump is dependent on how old your baby is, what time of day you pump, when you last nursed or pumped and your breast storage capacity.

Most lactating people make more milk in the morning so it is a good time to pump
Wait 30 - 60 minutes since the last milk removal

The average amount that parents pump during a regular pumping session is 90-120 ml.(6) If you are pumping between feeds, the amount may be closer to 45-60 ml.

Pumping Breastmilk Tips

Pump Parts

Make sure all your pump parts are in well working order. Some of the parts will need to be replaced more frequently than other parts. How often you replace them depends on how often you are pumping. The below guidelines are based on pumping 3 times a day or more to less than 3 times per day. The more often you pump the sooner the parts will wear out.

Duckbills every 1-3 months
Valve membranes every 2 weeks - 2 months
Backflow protectors every 3 - 6 months
Shield/flange - as needed
Tubing - as needed

Flange Fit

Pumping should be comfortable and never hurt. If a flange is too big or too small it can be uncomfortable and cause damage to the nipple and areola. If the shield/flange is the wrong size, it will not be as effective at removing milk and can affect your milk supply over time. If you’re taking the time to pump, you want to get the most milk possible.

Flange/shield size can change over the course of nursing. A nipple ruler can be a helpful tool for finding your correct flange size. Many IBCLCs/ SACLCs offer Flange Fitting Consults.

Expressing Your Milk

It can take time and practice pumping for your body to respond to the pump. The baby is better than any pump at removing milk. It is common not to see immediate results. There are some techniques that can help:

Hands on pumping - always use gentle touch!
Add heat - use a warm heat pack to encourage milk flow
Breast compressions(5)
Relax! Stress inhibits milk flow

Storing Your Milk

Always wash your hands and storage containers before pumping and storing your milk
Label the storage container with the date (and child’s name if needed)
Store 60-120 ml per container. Smaller amounts are better so milk is not wasted
Freshly pumped milk can stay at room temperature for 4 hours (up to 6 - 8 hours)
In the back of the refrigerator for 4 days (up to 8 days)
In the freezer section of a refrigerator for 9 months
In a deep freezer for 12 months

Using Your Stored Milk

Milk quality does degrade the longer it is in the freezer, so it is best to only store what you will need for your baby for a couple of days in most circumstances.(7) Store newly pumped milk in back of older pumped milk so you grab the older pumped milk to give your baby first.

Thaw milk from the freezer in the fridge overnight
Never microwave or heat milk on the stove
Warm defrosted milk in a sealed container in a bowl of warm water
Always check milk temperature before feeding your baby
Shake or stir milk to avoid hot spots
Use thawed milk within 24 hours and room temperature milk within 2 hours
Never refreeze thawed milk
If milk is leftover after you feed it to your baby, it should be used within 2 hours

Learning about pumping can seem overwhelming at first. Having some basic tips and facts about what to expect can help make it easier. Experimenting is part of the process of what works best for you and your baby and your IBCLC/SACLC is always available if you need a little extra guidance