13/10/2025
The received wisdom* that many of us in the breastfeeding world have absorbed is that women make more breastmilk in consecutive lactations. The thinking is that there is increased growth of glandular tissue during each pregnancy, and that that means more milk.
This Australian study sought to investigate this theory. It compared milk intake over 24 hr periods in infants between 2 weeks and 6 months, with the same measurements for a subsequent baby (the 2 lactations were 2.3 +/- 0.9 years apart). Total milk intake was calculated using pre and post feed weighing by the mothers.
It was found that there was no significant difference between the data for the first and second lactation for the mothers who were exclusively breastfeeding. For mothers in the study who were partially breastfeeding, a small increase in milk production was observed.
The study concludes by saying that
- in exclusively breastfeeding women there is no effect of consecutive lactation on 24 hr milk production.
- women that supplement with formula may have a higher milk production in a subsequent lactation, provided there are no intrinsic causes of low milk supply. The study seems to suggest that the increased milk production could be attributed to breastfeeding education and support.
Please note: Participants in this study did not have underlying causes of low milk supply. We need another study that explores milk production in consecutive lactations in mothers who have IGT.
Did you make more milk with second or subsequent babies?
I've seen mothers with low milk supply who seemed to have a slightly better supply with second or third babies. But I think that was more to do with the effort they put in to breastfeeding & optimising milk production, than having more glandular tissue.
Warden, A. H., Sakalidis, V. S., McEachran, J. L., Lai, C. T., Perrella, S. L., Geddes, D. T., & Gridneva, Z. (2025). Consecutive Lactation, Infant Birth Weight and S*x Do Not Associate with Milk Production and Infant Milk Intake in Breastfeeding Women. Nutrients, 17(6), 1062
*something that people accept as true, without question