Here is some information plucked (and updated with a new web url) from
messages I posted about a year and a half ago about breastfeeding and
diving (some of it perhaps more basic than you need, but take from it what
is relevant):

For the most expert advice regarding the physiology of diving, please phone
Divers Alert Network (a non-profit organization based at Duke University
Medical Center in the U.S. specifically for diving medicine information) =
919-684-2948, http://www.diversalertnetwork.org/

There are no known contraindications for breastfeeding and diving.  From
what I know of the physiology of diving, I am not aware of anything that
would cause a specific problem outside of the general risks of diving.

In a nutshell:  Air is made up of approx 80% nitrogen and 20% oxygen
(roughly).  The oxygen is metabolised.  The nitrogen (inert gas) under
pressure dissolves in the bloodstream and is taken up in the tissues (the
amount varies by time/length of dive, depth/pressure, and tissue).  I
assume, then, it could also be present in the milk, but I doubt this is of
any concern.

As pressure reduces (upon ascent), the nitrogen comes out of solution.  If
this happens slowly, it is exhaled and all is fine.  If it happens too
quickly, bubbles can form which cause "decompression sickness" - a serious
concern for *any* diver.  (Imagine shaking a bottle of carbonated drink and
opening it quickly.)

Fat tissues hold more nitrogen and thus take the longest to clear, so the
risk of decompression sickness is greatest in bodies high in fat tissue.
Also, dehydration is a factor in decompression sickness.  So hydration
would be important (again, for *any* diver).

The nitrogen that *might* be in the milk after a dive (probably very
little) would not be a decompression risk for the baby because it's in the
digestive system, not the circulatory system.  One might even speculate
that it could help the diver to "off-gas" by nursing :-)

Perhaps, the fit of the gear could possibly contribute to mastitis, like a
tight bra might  (snug wetsuit, heavy backpack).

Sometimes people are concerned with the effects increased pressure at
depth.  Outside of normal diving concerns, it should not be a special
concern for lactating mothers.  Pressure doesn't likely contribute to
mastitis or leakage (in and of itself) because pressure is distributed
THROUGH a fluid (and the body is mostly fluid).  The pressure of the liquid
cells in the body is equal to the ambient pressure.  Liquid is
incompressible -- your body doesn't get smaller when you dive (the
gas-filled cavities, lungs and middle ear, are equalized too).

There is no evidence supporting any increased risk of shark attraction to
breastmilk.  Most likely the volume of leakage would be small enough not to
be of concern.  My gut feeling is that a proper fitting wetsuit would
contain the milk well enough.

***** I would caution any diver (lactating or not) to take her dive
training, experience, and fitness level into consideration when planning
her dives. *****

A woman should *NOT* dive while pregnant.  The risks to the fetus are great.

Again, for the most expert advice regarding the physiology of diving,
please phone Divers Alert Network (a non-profit organization based at Duke
University Medical Center in the U.S. specifically for diving medicine
information) = 919-684-2948, http://www.diversalertnetwork.org/

Susan Horein
Wisconsin, USA
mailto:[log in to unmask]

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