Motherhood 2, breastfeeding: the theory
It’s natural!
Mother’s milk, what could be better, right? It is as nature intended, it does not require heating, it does not get spoiled, it is there when the baby needs it and in the exact amount too. What’s more to ask? Everyone and their aunt know this for a fact.
So, let’s assume everything goes smoothly: a woman goes through the gruelling 24 or so hours of childbirth, or alternatively has her belly literally cut open and sewn, and finally puts the newborn to her breast. This is it, the magic moment of extreme intensity! She has just brought a new person to this world and will now proceed to nourish them from her own very essence. She’s been waiting for it for so long! She is tired though, the baby is suckled but seemed to have had very little if anything. Well, it’s ok, this is the first day only, surely tomorrow she will produce more. Then the second day comes and third and forth and still only drops of milk and this is the only amount we’re speaking about. How about the much awaited bliss and tranquility she’d seen so many times on TV? There’s none of it as yet, instead
“it feels as if a barracuda had attached itself to one of the most tender and sensitive parts of your body”,
as one mom and a pediatrician have put it.
By day 4–5 the mother starts to panic that her child is starving and it is all her fault. They aren’t even over the first week of life and she’s already failing them. She is encouraged to continue to put the child to her breast and to supplement in the meantime with formula. But she is sleep deprived, still recovering from the birth (whichever way she did it), might also experience postpartum blues and her breasts are sore and cracked due to being soaked in saliva, compressed, sucked at and sometimes even chewed on. For some with perseverance, good advice, and a bit of luck the milk will come, but one can only be expected to tolerate so much before giving up.
And thus it is unfortunately not too uncommon to let go and switch to formula during as early as 2nd week of life. And don’t get me wrong, in some aspects modern formulas are even better than milk and are a necessity for so many kids, but the problem here is that breastfeeding does not happen by magic, it is a process that might take as much as 4–6 weeks. Thus, it is essential to be aware of some facts related to lactation if one embarks on the adventure of having a child.
Let’s take a look at the structure of the breast to begin with:
What you see on the schematic depiction above is a front view of a breast. It consists of multiple sac-like structures (lobules) that form lobes. Lobes are lying within a scaffold of fatty tissue and suspensory ligaments piercing through from surface to the chest wall (not depicted here). The two serve as a structural support and are of less importance to our current topic, but they are worth mentioning as they are in part responsible for the somewhat lumpy texture of a perfectly normal breast. The production of milk happens in the lobules from where it goes via ducts from periphery towards the center of the breast where lies areola (the bigger circle in the middle, IRL the whole darker pigmented area atop the breast) and the nipple (the smaller one at the center of it all). Just under the skin of areola the ducts are somewhat enlarged and a small amount of milk can pool there. Apart from lactiferous ducts that open on the surface, there are also sebaceous glands that give the areola’s surface a bumpy look. These secret sebum or skin oil to try and reduce skin irritation and breakage that inevitably follows breastfeeding.
Now, let’s review how it’s regulated. Here, the prolactin is IT. It is produced in tiny quantities at baseline by the pituitary gland or hypophysis which sits inside the skull just above the one of nasal sinuses. Remember how the COVID nasal swab would seem like it was poking your brain? It was not that far off. A bit higher up and with appropriate tools is the route employed by surgeons when there is a need to access pituitary, usually to remove a tumor that would not yield to more conservative measures, without having to open up the skull and go through all the stuff in the way. So when a person becomes pregnant a series of hormonal changes occur: among them increase in estrogen secretion which stimulates pituitary and induces amplification in the number of cells producing prolactin to gradually prepare the body for milk production. This in turn leads to an increase in number of cells producing milk within the breast and consequent increase in breast volume. There are other active compounds and some medications that can stimulate those cells as well, but let’s keep on the pregnancy related cause here.
As long as placenta is in place and pregnancy is ongoing, progesterone secreted by the latter will keep milk secretion on hold. However, upon birth the quantity of progesterone in blood drops sharply and the brakes come off prolactin. For some women it might mean a relatively quick introduction into the wonders of breastfeeding, but not for many, thus comes in another important factor — suckling. Most, if not all, hormonal activities work with some degree of autoregulation or feedback loops, same goes for lactation. Suckling is the signaling needed to commence and maintain milk production, which is why the modern standards of obstetrics insist on putting the newborn to the breast ASAP. The time spent on the breast, if you will, translates into the actual amount of milk needed, thus more suckling -> more milk. An interesting aside: prolactin secretion and breastfeeding suppress ovulation to a certain degree and thus chances of getting pregnant again. It is not a reliable method of contraception, as attested by, in part, by many-a-sibling with an age difference under about 2 years, but nature sure tried to increase the chances of survival of this one newborn by virtue of reducing competition. But getting back to breastfeeding: another hormone tied closely to is oxytocin which helps with milk let down and promotes uterine contractions. It also serves to help the new mother to bond with her baby thus increasing the latter chances of survival. It has other fascinating areas of influence that are once again beyond the scope of this post, but it has to do with behavior as greatly expounded by Robert Sapolsky in “Behave: The Biology of Humans at Our Best and Worst” and in series of lectures.
The milk that is produced over the first days, or colostrum, is thicker in consistency and consequently richer in nutritional value as compared to full milk that will come later on. It also acts as a laxative to help evacuate the bowel contents and clear bilirubin from the body. The full milk in turn has two fractions, as it were: the foremilk (more watery, sort of superficial portion) and the hindmilk (thicker one, coming out at the end of a feeding session, from an almost empty breast). Breast milk is not just a sustenance source but sort of a booster as it contains a lot of biologically active substances from IgA that helps to resist upper respiratory and GI microbial offenders to growth factors. It contains almost everything the baby will need in their first 6 months of life, apart from vitamin D and iron which are often recommended supplements as breast milk has negligible amounts of those. It is especially important (and here we have most solid science) for the premature infants (born before 37 weeks) as although modern day baby formulas are varied and quite good, they do not provide the protection from one of the much feared complications of prematurity — necrotising enterocolitis.
So, overall no big surprises here, I think. Breast milk = good. We know and have been told ad nauseam that “breast is best” and in the next post we’ll discuss what challenges might arise and what one can do to help self or others.
