You would think that the stronger a breast pump can suction, the better. But before you crank that pump to the highest setting, make sure you know the benefits (and risks) of doing that. Breast pump suction power is measured in mmHG (millimeters of mercury), the standard unit of measuring vacuum pressure. Studies were done on babies sucking at the breast and breasts pump suction levels are based off what we know of how babies remove milk from the breast. The suction level, or vacuum, is different than the cycle speed, which is how fast it pumps. This is why breast pumps should have two settings: cycle (speed) and vacuum (strength). Most pumps will cycle at 40-70 cycles per minute. This is based off of the average number of sucks a baby does at the breast in that same amount of time. Every baby sucks are their own pace and with their own vacuum strength.
Every pump has its own max suction strength that it can reach. “Hospital grade” pumps generally have maximum suction levels in the 300+ mmHg range while personal grade pumps are generally in the 200+ mmHg range. This doesn’t necessarily make a pump better or worse. The highest suction level on most pumps are actually above the comfort zone of the majority of pumpers. Most people feel comfortable expressing in the range of 150 – 200 mmHg regardless of whether the pump can reach 250 or 350 mmHg at its max. Using the suction too high, especially in combination of the wrong size flanges, can hinder milk flow and be the root cause of plugged ductsmastitis, dropping milk supply and breast/nipple damage!
Think of it like drinking from a milkshake with a narrow straw. When you suck too hard, the straw starts to collapse on itself and the shake is really hard to drink. Milkshakes move better with gentle, consistent sucking that doesn’t collapse the straw. Milk ducts are like compressible straws inside the breast that move milk from the milk-making glands called alveoli to your nipple pores in your nipple to your baby. Not only does everyone have a different number of these ducts, but the diameter of the ducts also varies from person to person. Too much breast pump suction compresses the areolar tissues which pinches off the ducts and actually decreases the flow of milk to the pump. With time this can cause milk to back up in the breast, increasing the risk of plugged ducts. This can also foster inflammation and risk damage. This also leaves milk behind which eventually can drop your overall milk supply. Having the right size flange AND using enough suction to move milk but not compress the ducts is essential to a happy pumping journey.
