Lactation Narration

The previous (2005) version of the AAP’s (American Academy of Pediatrics) Breastfeeding and the Use of Human Milk document, had the following statements about breastfeeding beyond infancy (emphasis mine):

Pediatricians and parents should be aware that exclusive breastfeeding is sufficient to support optimal growth and development for approximately the first 6 months of life, and provides continuing protection against diarrhea and respiratory tract infection. Breastfeeding should be continued for at least the first year of life and beyond for as long as mutually desired by mother and child.

There is no upper limit to the duration of breastfeeding and no evidence of psychologic or developmental harm from breastfeeding into the third year of life or longer.

This was a very supportive statement for those of us who nurse beyond infancy, and even beyond toddlerhood into the pre-school years. I have pulled out this AAP statement many times to defend myself from those who would call breastfeeding beyond infancy not just un-beneficial, but actually harmful to children.

I have also used the AAFP (American Academy of Family Physicians) statement from its 2008 position paper:

NURSING BEYOND INFANCY
As recommended by the WHO, breastfeeding should ideally continue beyond infancy, but this is not the cultural norm in the United States and requires ongoing support and encouragement. It has been estimated that a natural weaning age for humans is between two and seven years. Family physicians should be knowledgeable regarding the ongoing benefits to the child of extended breastfeeding, including continued immune protection, better social adjustment, and having a sustainable food source in times of emergency. The longer women breastfeed, the greater the decrease in their risk of breast cancer. Mothers who have immigrated from cultures in which breastfeeding beyond infancy is routine should be encouraged to continue this tradition. There is no evidence that extended breastfeeding is harmful to mother or child. Breastfeeding during a subsequent pregnancy is not unusual. If the pregnancy is normal and the mother is healthy, breastfeeding during pregnancy is the woman’s personal decision. If the child is younger than two years, the child is at increased risk of illness if weaned. Breastfeeding the nursing child after delivery of the next child (tandem nursing) may help provide a smooth transition psychologically for the older child.

and the AAFP 2007 policy statement also states:

Breastfeeding beyond the first year offers considerable benefits to both mother and child, and should continue as long as mutually desired.

The AAP has released a new and updated document today on Breastfeeding and the Use of Human Milk. The new 2012 version does not say much about extended breastfeeding, only the following:

The AAP recommends exclusive breastfeeding for about 6 months, with continuation of breastfeeding for 1 year or longer as mutually desired by mother and infant, a recommendation concurred to by the WHO and the Institute of Medicine.

Mothers should be encouraged to continue breastfeeding through the first year and beyond as more and varied complementary foods are introduced.

While this is still supportive of breastfeeding beyond infancy, I wonder why this topic was not covered as fully in this revision? Was it an oversight? I would have appreciated more on this topic from the new AAP statement, not less.

I participated in a study recently, in which the researcher was investigating the maternal cells present in breast milk. She needed fresh milk for the study, so I went to her lab to express some milk.

She provided a Medela Symphony breast pump for the mothers in the study, but I found that it didn’t really work for me to pump. Sweets is over 2.5 years old now and it’s been a year since I pumped at work. She typically only nurses 1-2 times per day, so I don’t have a lot of milk anymore, and the pump just wasn’t doing anything.

I decided to hand express instead, and I did get a little milk that way, but only about 6 mL. For reference, there are about 30 mL to an ounce, so that is really not very much milk!

The researcher let me watch as she centrifuged my milk sample, which separates the fat to the top of the sample and the cells to the bottom with the liquid portion of the milk in between. Then she removed everything except the cell pellet, washed the cells, and centrifuged them again. After the cells were washed, she looked at them on a microscope to count them. This is what we saw.

And from that little 6 mL, she was able to get 7,850,000 cells! That is 1.3 million cells per mL, which would be almost 40 million cells per oz! She had several experiments she wanted to do with the cells, and while this was enough for one experiment, it would not be enough for all of them. She encouraged me to come donate again if I was willing and able.

I went back two more times, with pretty similar results. The second time I had 6,160,600 cells in 5 ml of milk. The third time I had 9 million cells in 7 mL of milk.

Donation	Total Cells	mL	cells/mL	cells/oz
1	7,850,000	6	1,308,333	38,692,035
2	6,160,600	5	1,232,120	36,438,137
3	9,000,000	7	1,285,714	38,023,109
		Average	1,275,389	37,717,760
		Std Dev	39,142	1,157,559
		Std Err	22,598	668,317

Not too bad for 2.5 years out! Next time someone tells you that there are no benefits to breastfeeding past a certain age, don’t believe it!  Most of the mothers who donated to the study had about half as many cells per mL than I did (though of course they had more milk volume too).

So the next question is, what are all those cells?

Most of the cells in milk are mammary epithelial cells.  The research study I donated to is investigating mammary stem cells in this subset.  Total leukocyte (white blood cell) counts are reported to be 4 million/mL in colostrum and 0.1-1 million/mL in mature milk. These are comprised of about 55-60% macrophages, 30-40% neutrophils, and 5-10% lymphocytes. Of the lymphocytes, about 80% are T cells and about 5% are B cells. Of the T cells, both CD8+ (cytotoxic) T cells and CD4+ (helper) T cells were present, and most were activated memory cells.

In short, a whole variety of live cells are present in breast milk. Milk is more than just a source of food for the infant. These cells can be absorbed by the infant through the mucosal membrane of the intestine, where they continue to carry out their normal functions. (One interesting side-effect of this is that it is postulated that kidney transplant recipients who were breastfed as infants and receive a half-matched kidney donated by their mother are less likely to experience rejection than those who were not breastfed, or those who receive a half-matched kidney donated by their father.) The maternal immune cells continue to  support and influence the child’s immune system.

It is an amazing gift that I give to my child, of my own body. Truly.

I don’t know how she does it, but on weekends Sweets is like an alarm clock. She wakes up right at 7am, no matter when she went to bed.

But on weekdays, I often have to wake her up to get her ready for daycare.

This morning, I went to wake her up at 7:15, and she was grumpy!

She didn’t want to get dressed, she didn’t want to eat breakfast. But she did ask to nurse.

Sweets hasn’t been nursing in the morning every day lately. She used to always nurse twice per day: in the morning when we get up and when we got home from work. But lately, she skips one or even both of these some days. She skips the morning nursing more often, and I’d say she only nurses in the morning about 60% of the time lately.

But this morning, she wanted to nurse. And she didn’t want to nurse in this seat, it had to be in that seat.

THAT ONE!

I’m telling you, grumpy.

She nursed for maybe 20 minutes and got progressively happier and happier and more giggly and playful as she switched back and forth a few times between sides.

When she was done, she started just looking up at me with the most smiley, happy face! She was just so adorable!

I looked down at her and I said “Oh, I just love you!”

And she looked back at me and said “Yah Yoo Doo.”

Love You Too.

And my heart melted.

And then she happily got down and went to the kitchen to eat the waffle that was waiting for her. Then she trotted over to the door, ready to go, and said happily “Ass Doh!” (Let’s Go!)

I’m so glad we are still nursing. We can still turn a grumpy morning into a happy morning, just like that!

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This post has been cross-posted from my other blog, My Baby Sweets.