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Help! How do I know what size breast sheild to use?

Posted by on Nov. 9, 2011 at 6:50 PM
  • 4 Replies

I have been pumping for a few days now with the Medela double pump, I usually pump one breast while LO is feeding on the other.  I started using the 24 mm but I am now using the 27 mm.  I think it may by to small but I'm not sure how to tell, it is pretty uncomftrable.  I don't have alot of money so I don't want to buy another sheild if it is not going to help.  I am wondering if there is an easy way to tell if I need to buy a bigger shiled or what size to use?

by on Nov. 9, 2011 at 6:50 PM
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by on Nov. 9, 2011 at 8:46 PM
I used the 27mm shields once. I pumped and after that all around my nipple was bleeding. My LC gave me 30mm shields and havent had problems yet.
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by on Nov. 9, 2011 at 8:56 PM

Proper Fitting of Breast Shields

Correctly fitted breast shields are important to improve and maintain healthy milk production. Breast shields are the part of the milk collection kit that fit directly over the breast and nipple. The nipple is pulled into the tunnel of the shield with suction from the pump. It is estimated that 50% of mothers who use breast pumps need a larger shield size.

To accommodate the needs of mothers, Medela has developed customized breastshields. These are designed to allow for the larger tunnel size that some women need while pumping. Medela provides a two-piece system that allows a connector to interchange with any of the different sizes of their PersonalFit Breastshields.

Medela - Good Fit

Correctly fitted breast shields lead to:

  • Optimal breast emptying
  • Avoidance of nipple discomfort while pumping
  • Prevention of tissue damage from pumping

Why is breast emptying affected by tightly fitted shields?

  • If shield size is too small, the milk ducts in the nipple are compressed (squeezed) just when the milk should be flowing out of the nipple during milk ejection. (Like pinching a straw closed when you are trying to drink from the straw.)
  • This results in milk stasis (back up) and can lead to plugged ducts, mastitis, or problems with low milk production. If this occurs, a woman often feels "lumps" in her breast after pumping.
  • The outcome over time is low milk volume from lack of proper emptying of the breasts. The milk that remains in the breast after pumping provides negative feedback to the breast, and milk production decreases.

Medela - Too Tight
How do you know if you need larger breast shields?

  • Observation of the nipple during pumping is crucial (preferably after 5 minutes or more of pumping). Some women experience swelling of the nipple during pumping and that's why it is important to observe the nipple during a pumping session.
  • All of the nipple (protruding part of the areola) should fit into the tunnel of the shield. The nipple should move in and out of the tunnel easily. If you observe the nipple rubbing against the side (or sticking to the side) of the tunnel, the shield size is too small.
  • If the base of the nipple is blanching (turning white) while pumping, then the shield size is too small.
  • If you have nipple discomfort or pain while pumping, you may need larger shields. If the tip of the nipple hurts while pumping, the nipple is not properly centered in the shield. (It is difficult to see this on yourself. Ask someone else to observe you.) If the pain is on the side of the nipple, then the shield size is too small. The pain comes from the friction of the nipple shaft rubbing against the inside of the tunnel in the breast shield.
  • If you observe a ring of sloughed skin (or specks of skin) on the inside of the shield after you remove the shield, you may need a larger shield size.

Good Fit

Too Tight

Helpful Hints:

  • Sometimes a bigger shield is not better. Let comfort be your guide. Some women find that they need one size shield for one breast and a different size shield for the other breast. 
  • It is important for the shield to have contact with the areola. You should not see air gaps between the aerolar tissue and the shield while pumping. The shield should stay in firm contact with the aerolar tissue and surrounding skin of the breast. 
  • Don't press the shield into the breast really hard, it will block the ducts. 
  • If you are pumping 5-8 times per day, apply Nipple Cream to the nipple and areola prior to pumping for a better seal and to prevent abrasion of the nipple.
  • Choosing the correct size of the shield requires experimentation. Observation, comfort and results are the best ways to determine which size is correct for you.
  • Some women find their need for larger shields decreases after the baby is 4-6 weeks old.
  • Other women find that the larger shields are not necessary until they return to work and start pumping more often to supply their baby with breastmilk at home. A decrease in milk supply after returning to work can often be reversed by using larger shields and taking herbs to increase milk supply like More Milk Plus.

If tightly-fitted breast shields are the cause of the milk volume problem, you will feel relief from the nipple pain almost immediately with larger shields. Nipple Cream is very healing to nipple tissue that has been damaged by small shields and/or frequent pumping sessions.

Janet Talmadge, BA, IBCLC
Lactation Innovation, Naperville, IL

Web site:

(630) 399-2415

Changing the world, one healthy breastfed baby at a time!

©2009 Lactation Innovation

by on Nov. 10, 2011 at 1:52 PM
Oh wow thank you, very helpful
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