To understand how to effectively increase (or decrease) milk supply, we need to look at
how milk production works…
| For the most part, milk production is a “use it or lose
it” process.The more often and effectively your baby nurses, the more
milk you will make. |
In the Beginning…
Endocrine (Hormonal) Control of Milk Synthesis — Lactogenesis I & II
Milk production doesn’t start out as a supply and demand process.
During pregnancy and the first few days postpartum, milk supply is
hormonally driven – this is called the
endocrine control system.
Essentially, as long as the proper hormones are in place, mom will
start making colostrum about halfway through pregnancy (Lactogenesis I)
and her milk will increase in volume (Lactogenesis II) around 30-40
hours after birth.
During the latter part of pregnancy, the breasts are making
colostrum, but high levels of progesterone inhibit milk secretion and
keep the volume “turned down”. At birth, the delivery of the placenta
results in a sudden drop in progesterone/estrogen/HPL levels. This
abrupt withdrawal of progesterone in the presence of high prolactin
levels cues Lactogenesis II (copious milk production). Other hormones
(insulin, thyroxine, cortisol) are also involved, but their roles are
not yet well understood. Although biochemical markers indicate that
Lactogenesis II commences approximately 30-40 hours after birth, mothers
do not typically begin feeling increased breast fullness (the sensation
of milk “coming in”) until 50-73 hours (2-3 days) after birth.
These first two stages of lactation are
hormonally driven – they occur whether or not a mother is breastfeeding her baby.
Established Lactation…
Autocrine (Local) Control of Milk Synthesis — Lactogenesis III
After Lactogenesis II, there is a switch to the autocrine (or local)
control system. This maintenance stage of milk production is also called
Lactogenesis III. In the maintenance stage, milk synthesis is
controlled at the breast — milk removal is the primary control mechanism
for supply. Milk removal is driven by baby’s appetite. Although
hormonal problems can still interfere with milk supply, hormonal levels
play a much lesser role in established lactation. Under normal
circumstances, the breasts will continue to make milk indefinitely as
long as milk removal continues.
By understanding how local/autocrine control of milk synthesis works,
we can gain an understanding of how to effectively increase (or
decrease) milk supply.
What does current research tell us about milk production?
Current research suggests that there are two factors that control milk synthesis:
Milk contains a small whey protein called
Feedback Inhibitor of Lactation (FIL) – the role of FIL appears to be to
slow milk synthesis when the breast is full. Thus milk production
slows when milk accumulates in the breast (and more FIL is present), and
speeds up when the breast is emptier (and less FIL is present).
The hormone prolactin must be present for milk synthesis to occur. On
the walls of the lactocytes (milk-producing cells of the alveoli) are
prolactin receptor sites that allow the prolactin in the blood stream to
move into the lactocytes and stimulate the synthesis of breastmilk
components. When the alveolus is full of milk, the walls expand/stretch
and alter the shape of prolactin receptors so that prolactin cannot
enter via those receptor sites – thus rate of milk synthesis decreases.
As milk empties from the alveolus, increasing numbers of prolactin
receptors return to their normal shape and allow prolactin to pass
through – thus rate of milk synthesis increases. The prolactin receptor
theory suggests that frequent milk removal in the early weeks will
increase the number of receptor sites. More receptor sites means that
more prolactin can pass into the lactocytes and thus milk production
capability would be increased.
Both of the above factors support research findings that tell us:
 |
FULLBreast |
= |
SLOWERMilkProduction |
|
 |
EMPTYBreast |
= |
FASTERMilkProduction |
|
Research indicates that
fat content
of the milk is also determined by how empty the breast is (emptier
breast = higher fat milk), rather than by the time of day or stage of
the feed.
How does milk supply vary throughout the day?
Earlier researchers observed that milk volume is typically greater in
the morning hours (a good time to pump if you need to store milk), and
falls gradually as the day progresses. Fat content tends to increase as
the day progresses (Hurgoiu V, 1985). These observations are consistent
with current research if we assume the researchers were observing babies
with a fairly typical nursing pattern, where baby has a longer sleep
period at night and gradually decreases the amount of time between
nursing as the day progresses.
Storage
capacity: Another factor that affects milk production and breastfeeding
management is mom’s milk storage capacity. Storage capacity is the
amount of milk that the breast can store between feedings. This can vary
widely from mom to mom and also between breasts for the same mom.
Storage capacity is not determined by breast size, although breast size
can certainly limit the amount of milk that can be stored. Moms with
large
or small storage capacities can produce plenty of milk
for baby. A mother with a larger milk storage capacity may be able to go
longer between feedings without impacting milk supply and baby’s
growth. A mother with a smaller storage capacity, however, will need to
nurse baby more often to satisfy baby’s appetite and maintain milk
supply since her breasts will become full (slowing production) more
quickly.
Think of storage capacity as a cup – you can easily drink a large amount of water throughout the day using
any size of cup – small, medium or large – but if you use a smaller cup it will be refilled more often.
What does the research tell us about increasing milk supply?
Milk is being produced at all times, with speed of production
depending upon how empty the breast is. Milk collects in mom’s breasts
between feedings, so the amount of milk stored in the breast between
feedings is greater when more time has passed since the last feed. The
more milk in the breast, the slower the speed of milk production.
To speed milk synthesis and increase daily milk production, the key
is to remove more milk from the breast and to do this quickly and
frequently, so that less milk accumulates in the breast between
feedings:
|
EMPTYBreast |
= |
FASTERMilkProduction |
|
In practice, this means that a mother who wishes to increase milk
supply should aim to keep the breasts as empty as possible throughout
the day.
To accomplish this goal and increase milk production:
- Empty the breasts more frequently (by nursing more often and/or adding pumping sessions between nursing sessions)
- Empty the breasts as thoroughly as possible at each nursing/pumping session.
To better empty the breasts:
- Make sure baby is nursing efficiently.
- Use breast massage and compression.
- Offer both sides at each nursing; wait until baby is finished with
the first side before offering the second. Switch nursing may be helpful
if baby is not draining the breast well.
- Pump after nursing if baby does not adequately soften both breasts.
If baby empties the breasts well, then pumping is more useful if done between nursing sessions (in light of our goal to keep the breasts as empty as possible).
Are you having problems with oversupply?
Mothers who are working to remedy oversupply usually need to decrease supply
without
decreasing overall nursing frequency or weaning baby. One way to
accomplish this is by “block nursing” – mom nurses baby as frequently as
usual but restricts baby to one breast for a set period of time (often
3-4 hours but sometimes longer) before switching sides. In this way,
more milk accumulates in the breast before mom switches sides (thus
slowing milk production) but baby’s nursing frequency is
not limited.
Source:
http://kellymom.com/pregnancy/bf-prep/milkproduction/
