Exclusive Pumping Output Case Study

My friend Nico, who was immeasurably helpful to me when I was trying to get and stay pregnant with my babies, exclusively pumped for her third son. She kept track of all of her output in an app, and was awesome enough to download the data so that I could play with it. I thought that I’d present the results here as an exclusive pumping output case study.

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The below graphs show how Nico’s pumping output was affected by time, length of session, how many pumping sessions she was doing, etc.

How Does Milk Supply Change Over Time?

The first graph shows the average amount of milk (in oz) that Nico pumped during each session for the first year (the numbers at the bottom represent months post-partum):

Here you can see how her output shoots up in her second month post-partum, stays pretty stable for awhile, and then starts a slow descent in month 8. It’s also worth noting that she got her period back at the 11 month mark, which might be partially responsible for the accelerated drop there.

What is the Relationship Between Total Output and Amount of Time Spent Pumping? 

This graph shows the average amount of milk that was pumped by the length of the pumping session:

What this graph seems to show is that the amount of milk that Nico pumped increased proportionally to the amount of time that she spent pumping until about the 20 minute mark. After that point, there really doesn’t seem to be any benefit in pumping longer.

Does Each Side Produce About the Same Amount of Milk?

Nico’s app tracked output for each side, so I thought I’d see if she had a “dominant” producer:

It’s interesting to see here how the left side starts off as the higher producer, it evens out at month 5, and then rightie pulls into the lead at 8 months post-partum. My left side has always been my “money boob,” because I’m right-handed and tend to do more compressions on the left. (This is not very smart. Learn from my lopsidedness!)

How Do the Number of Pumping Sessions Per Day Affect Milk Output?

The below graph shows how Nico’s total daily output changed based on how many times she was pumping per day:

A lot of people wonder whether or not their supply will drop if they drop a pumping session. In Nico’s case, her supply stayed the same when dropping from 7 to 6 pumps and from 5 to 4, but otherwise did drop about 5 ounces with every pumping session that she dropped.

Here we can see that even though the total amount that Nico pumped went down as she dropped pumps, the amount that she pumped per session went up, with the highest average output per session at two pumps per day.

How Does Milk Production Vary Throughout the Day?

When I saw a lactation consultant after my first baby was born, she said that milk supply tends to be highest in the the middle of the night/early morning and lowest in the early evening. (Kellymom mentions this here, though you need to scroll down a bit to see it.) This doesn’t really seem to have been the case for Nico. She pumped slightly more milk in the morning, but overall her output was pretty consistent regardless of time.

Overall, this is just one exclusive pumper’s experience in terms of output, but I really enjoyed taking a look at the data to see if there were any patterns or trends.

What do you think? Does this match with your experience?

(Also – do you have data for yourself in a pumping app that you’d be willing to export and share with me? I would be very grateful for any “data donations” and can keep you anonymous or not, whatever you’d prefer! You can contact me here – thank you!)