Initial Breast Milk Production

How long did it take for milk production to kick in?


The baby came on October 15th 2015. I'll write a future post dedicated to that time period (edit: Here is that post). What's relevant here is that the mother started breast pumping that night and attempted breast feeding the next day.

It took a fairly long time (several days) for breastfeeding to work for her and she got very discouraged. Luckily, she was breast pumping steadily (20 minutes per pumping session typically) and we tracked what she produced for the majority of pumping sessions, so she was able to see that breastfeeding was difficult primarily because she just wasn't producing much, and once she did produce, things went more smoothly.

In looking at the data, I wondered what to do with it and realized that it could be modeled reasonably well as a logistic function/sigmoid.

Using a modified least squares method, I came up with:

L = 112.1
k = 0.676
x0 = 22-Oct-2015 at 5:15 PM

The data plotted against this curve look like the following:

 

For reference...x0 tells you where the midpoint on the y-axis occurs, L tells you the value on the y-axis after a long time, and k tells you how quickly the curve moves from ~0 to ~L. Thus, this basically says that her milk production got halfway to maximum production about a week after birth (birth on October 15th and halfway point on October 22nd), peaked at around 112.1 mL, and took a few days to get from the halfway point to 90% of the max value. 

It should be noted that much of the variation in the data starting once she neared maximum production is almost certainly due to pumping too soon after breast feeding. In a later post, I will hopefully be able to get data on production vs time since feeding.

Finally...she is now using a progestin implant which can supposedly affect production, and we have been tracking it since she started so I will post if anything interesting comes up from that. I'd assume you get exponentially decaying production that settles on something like 80% pre-implant max, but who knows.