Breastpumping should not be painful and uncomfortable if you have the correct size of breastshield AND the correct motor power setting. This guide shows you how to choose the correct size of breastshields that fit you. As to the correct suction power, please refer to your pump manual for more details.
Step 1 - Measurement
Breastshield size (B) is defined as the inner diameter of breastshield tunnel.
The inner diameter of the breastshield (B) should be 1-2 mm larger than the diameter of your nipple (N) AFTER a pumping session or 3-5 mm BEFORE a pumping session. You should be able to see free movement of your nipple during pumping and there should be little or no suction of the areola into the tunnel of the breastshield.
It is not rare that the size of nipple changes for breastpumping mothers. What best fits today might not fit in the following months. In general, most mothers' nipples will become smaller when the milk supply goes down near the end of their pumping journey.
Need useful tool for measuring? You can download Maymom Nipple Ruler here. Just print it out, cut and fold according to the instructions. Watch Demo Video
Step 2 - Try On
We suggest that you start to try a breashield size that is 1-2 mm larger than your nipple diameter. If you measure your nipple diameter BEFORE a pumping session, we estimate that the breastshield shield size should be 3-5 mm larger than your nipple diameter.
However, each mom responds differently to pumping. The suggestion may not be optimal until you try it out.
| Nipple Diameter BEFORE pumping (mm) | Nipple Diameter AFTER pumping (mm) | Suggested Breastshield Size (mm) |
| 5-7 | 8-9 | 10 |
| 7-9 | 10-11 | 12 |
| 8-10 | 11-12 | 13 |
| 10-12 | 13-14 | 15 |
| 12-14 | 15-16 | 17 |
| 14-16 | 17-18 | 19 |
| 15-17 | 18-19 | 20 |
| 16-18 | 19-20 | 21 |
| 17-19 | 20-21 | 22 |
| 18-20 | 21-22 | 23 |
| 19-21 | 22-23 | 24 (Medela standard size) |
| 20-22 | 23-24 | 25 (Ameda standard size) |
| 21-23 | 24-25 | 26 |
| 22-24 | 25-26 | 27 |
| 23-25 | 26-27 | 28 |
| 24-26 | 27-28 | 29 |
| 25-27 | 28-29 | 30 |
| 27-29 | 30-31 | 32 |
| 29-31 | 32-33 | 34 |
| 31-33 | 34-35 | 36 |
Correct FIT
The nipple moves easily without any pain.
Breastshield is too big
The nipple and excessive areola are pulled into the tunnel. Try a smaller size.
Breastshield is too small
The nipple rubs along the side of the tunnel and causes discomfort. Try a larger size.
Breastshield is too short
The nipple hits the tunnel end. Try a longer or smaller size.
When it comes to pumping comfort, every millimeter counts. That is why we design a series of breastshields of small increment.
Maymom one-piece breastshields are available in 15, 17, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 34, and 36 mm internal diameters plus 10, 13, 15, 17, 19, 21, and 24 mm flange inserts to fit the majority of breast pumping mothers.
Step 3 - Pump and Observe
Center the nipple in the tunnel of the breastshield. Start pumping and check the following points:
| YES | NO | Question |
| Is your nipple moving freely in the tunnel? | ||
| Is none or only very little tissue of the areola being pulled into the tunnel of the breastshield? | ||
| Do you recognize gentle, rhythmic movements in the breast at each pump cycle? | ||
| Do you feel the breast emptying all over? | ||
| Is your nipple free of pain? | ||
| Is there still space between the tip of your nipple and the end of the nipple tunnel during pumping? |
All answers should be YES, which indicates you have correct breastshield size and correct motor suction power. If NOT, please consult your lactation consultant or stop using Maymom’s products to prevent further discomfort.