This research was done by Breastfeeding Arts. It is very informative and will help women answer questions about defrosted breastmilk.
Lots of conversation going on about re-freezing thawed breastmilk with Irene bearing down on the East Coast this weekend … and thought I’d share some of the information discussed in my lactation circles online.
Colleagues have discussed protocols … where if 50% or more remains frozen the milk can be refrozen. If more than 50% is thawed then you have the 24 hour rule. If the frozen ice crystals are still present in the milk, it can be refrozen, even if partially thawed …. things to keep in mind.
And then there’s this study & further links below …
(grateful for my IBCLC yahoo groups and colleagues for all this, thanks!)
Breastfeeding Medicine
Effect of Environmental conditions on Unpasteurized Donor Human Milk
To cite this article:
David J. Rechtman, Martin L. Lee and H. Berg. Breastfeeding Medicine. Spring 2006, 1(1): 24-26. doi:10.1089/bfm.2006.1.24.
The milk studied was donor milk expressed by mothers who took no special sanitary precautions. The milk was first stored at -20°C (-4°F) for two months and then at -80°C (-110°F) until its use in the experiment. Then the milk was thawed overnight to 4°C (39° F), separated into different sample batches, and refrozen to -80°C (-110°F).
The second phase of the experiment began by thawing these sample batches of milk to a room temperature of 23°C (73°F). Then each batch was exposed to one of the following conditions:
* 8°C (46°F) for 8 hours
* 8°C (46°F) for 24 hours * 23°C
(73°F) for 4 hours
* 23°C
(73°F) for 8 hours
* Multiple freeze-thaw cycles of varying lengths
* A steady -20°C (-4°F), considered the control
The Results
None of the milk developed unacceptable bacterial counts, the main concern about refreezing milk. In fact, they did not even come close.
There were some changes in vitamin content. Vitamin A levels stayed stable, but vitamin C levels decreased to about one-half when kept at room temperature for 8 hours and by one-fourth when refrigerated for 24 hours. However, the authors note that the reduced vitamin levels are considered adequate for full-term babies and older infants by the National Academy of Medicine.
Differences in fatty acids levels in the milk were considered clinically insignificant and unrelated to repeated freezing and thawing.
The authors write: “Based on these data, it appears that unpasteurized milk that has been thawed in the refrigerator for up to 8 hours may be safely refrozen….
This should allow for… the salvage of milk that mothers might otherwise have been told to discard.”
This study further confirms the robustness of human milk. If its results are replicated, it will also give clinicians another tool to help mothers meet their breastfeeding goals. Then, if due to a power outage or something else, a mother finds herself with a larger amount of thawed milk than her baby can take in 24 hours, she will have the option of refreezing her thawed milk rather than discarding it.
For mothers who express their milk, this information may help them use more and discard less, resulting in better health outcomes for their babies.
D.J. Rechtman, M.L. Lee and H. Berg, Effect of environmental conditions on unpasteurized donor human milk. Breastfeed Med 2006: 1(1):24-26.
Article available here.
