Transcription
[Music] hi I'm Karen bodar and I have been involved with Academy of breastfeeding medicine for quite some time. I am currently serving as a member of the board.
I'm also on the board of the North American Board of breastfeeding and lactation medicine and I run a breastfeeding and lactation medicine clinic in Northern Virginia. I also do a breastfeeding medicine podcast and webinar with the institute for the advancement of breastfeeding and lactation education.
I'm really excited to be talking about anatomy and physiology of lactation. I actually really love this topic because it's so important into what we do to take care of patients. When I was in medical school I remember learning very little about breast Anatomy besides the location and what lymph nodes cancer would spread too if people got breast cancer and then I had my own kids and I realized that when I was pumping milk was coming out of more than one hole and I was shocked. I really felt like I hadn't learned anything at all and so I got more involved and I learned a lot.
Really the structure of the breast is so important to the way that babies and parents work together with breastfeeding and I think that you know the very simple idea a that there are multiple loes in the breast there all these tiny little structures that um are sort of a little bit like grapes on a vine where the vine would be the part running through the nipple and areola and then the grapes are all of the Alvi in the breast helps us to understand how milk is produced and travels down and is extracted by the baby.
And there's actually been not a lot of research there's not a full understanding of everything we need to know. There's been debate for years are there milk duct sinuses sort of the end of the duct does it swell like when the original anatomist um injected paraffin wax into there or is it not like that. Breast surgeons are like I don't see any big sinuses and now we're starting to understand that really it's more of a potential space it's like an amboo bag when the milk is being ejected from the breast under the influence of hormones those Ducks swell up so that when babies compress the tissue the milk sprays out and I think that really helps us to understand when a section of the breast isn't draining well what's going on inside the breast.
There are all of these tiny little structures the Alvi and they're kind of pointed all different directions which can make it hard for um the breast to empty effectively when they're swelling and that's something that happens a lot in the early postpartum period. We know that early in development of you know in the embryo and even in puberty there are these little buds but the full formation of the gland doesn't happen until pregnancy and then milk can be produced after a delivery um the individual Alvi have wrapped around their basement membrane these myoepithelial cells which respond to oxytocin and contract and help the milk to move down to where the infant or a pump can extract it.
During pregnancy the um prolactin starts to go up higher and the withdrawal of the hormones of the placenta after delivery allows that to really act on the breast and that's when we get the transition from colostrum the small volume that's needed for the baby in the first few days to larger volumes of milk at that time. We also have learned that the tight junctions between the lactoyl in and that causes the sodium to drop before the increase in milk production when the lactose increases and now we're able to use that understanding in science to help us better understand when people are going through lactogenesis too. It's not just you know does this patient feel an increase in fullness we can really understand the science behind it to identify for instance parents who have babies in the ncu who are struggling with milk production what is the cause of their challenge is it more of a hormonal problem or more of a structural problem and then we can get them help.
We know that during pregnancy prolactin is going up up up to help the breast to grow and then the nipple stimulation that comes from baby suckling is what is going to lead for that repeated Spike of prolactin that tells the breast make more make more over the first few months and it's really important because people who don't have frequent nipple stimulation don't have prolactin that is at levels that is going to cause their milk production to increase. When we think about people who are choosing not to breastfeed or are really ill and are unable to initiate their prolactin goes back to non-lactating Levels by 2 weeks postpartum and that is why weaning naturally occurs if people don't have that frequent stimulation that's information that parents need to know because we can't unfortunately just breastfeed during the day and give babies bottles of formula at night it's not the way our bodies evolve to work.
Also we know that the level of prolactin doesn't directly lead to a certain level of milk there's a lot of variation and so so um there's a lot more research that needs to be done around this but people need that early nipple stimulation they also need to have really effective milk removal. Oxytocin is the other hormone that plays a big role because when we are feeding a baby or we hear them or we see them our pituitary releases this hormone that causes all of those Alvi to be squeezed by those little muscle cells and have the milk come down and I I think there are a lot of misconception perceptions about how milk is removed and I think it's really helpful to understand that babies are not working really hard to remove milk from the breast they have evolved to sort of sleep most of the time and drink when it's easy and I like to tell parents it's a feature not a bug that they sleep all day long and when they're on and that suckling causes oxytocin to be released and milk is Flowing like a waterfall they drink really easily.
Recently one of my um friend said to me it's kind of like when you're in the airport bathroom and you're waving Your Hand by the sink with the sensor and you're like come on come on and then the water starts to go that's what babies are doing when they're on the breast and they're nibbling and they're waiting and then when they're slow they drink for a few minutes of course the thing shuts off before you finished washing your hands the babies fall asleep and then they try again in a few minutes they get the rest.
One of the big things that interferes is encouragement and going back to you know when I had my first kids I was like like oh this is amazing my breasts are getting bigger I have a lot of milk I didn't really understand there is sort of a breast milk compartment in the breast and then there's a second space that is separate where any fluid that has leaked out of the tubes or alv lios any edema and that takes up space in the breast and it can actually compress the ducts in the nipple where the milk is supposed to exit and make it really hard for people to get out milk and it can be really confusing to families they think they don't have any when really they're just having trouble with removal because of that swelling and this is because there's a lot of edema in between all of the tubes and when milk leaks out into those spaces it is never going back into the tubes to come out the nipple it has to be removed in the way that edema gets out of our ankles it finds its way into the lymph nodes and back into our circulation and that's really important when we're treating people so that we're not telling them firmly massage your breast toward your nipple that isn't going to help in mastitis or any sort of enouragement light lymphatic massage toward the axilla is going to be far more effective.
Just a couple more things I will say I also see very frequently people who are pumping who have trauma because we haven't really done any studies telling us how should flanges fit and um sometimes people are using flanges that are too big and not only the nipple is going into the tube but a lot of the areola and that's problematic because if too much of it goes down it really causes swelling that compresses those tubes and sometimes even the denser glandular tissue that starts where the areola ends meets the back of the tube and can cause sort of a ball valve effect that really stops flow from the pump. People respond by turning up the vacuum they're really trying hard to get milk for their babies and that can make the swelling worse and it can be a vicious cycle it can be a really um hard thing for patients to understand and so teaching very simple techniques of hand expression on the areola to soften it can make a really big difference and should be first line in early days before pumping.
And lastly I think that it's really interesting to think about what is a normal amount of milk production. I really love this picture that a patient allowed me to take for teaching that shows what happens when somebody is breastfeeding on one side and they've weaned on the other side this patient had a 9-month-old who really had stopped taking one side many months before and so her one breast thought she had twins because that breast was doing two breasts worth of work and the other side had stopped and it's fascinating in that really many even pediatricians don't understand what milk volumes are needed for different sizes of babies and that really it's the baby's weight in combination with the age that tells us how much they need in the TW total 24 hours and that most babies Peak their milk intake by the time they are fiveish kilos and then they take the same amount of milk usually every day from about 3 months until their birthday and that means that while people are needing to increase milk in the early months then they're stable and I meet a lot of parents who are like oh how am I going to keep making more milk at six months and more milk at nine months and they don't know that's not necessary.
So really we can often help people even if they're giving some formula in the early days or even half and half to get back to making enough breast milk for their babies with great support and understanding so all of the things we learned about anatomy and physiology can help us to take great care of patients and I hope that this was helpful thanks have a great [Music] day [Music]