The stimulus for the alveolar cells of the breast to become sensitive
to prolactin is the drop in progesterone levels after delivery.  If
the progesterone levels do not drop, the cells do not become
sensitive.  Thus, if the mother is given the depoprovera too early, at
least in theory, the milk supply will not develop.  This obviously
does not occur all the time.

In practice, everything seems to be possible with depoprovera.
Increase, no change, and decrease.  I've heard it all and I don't know
what to say.  I would suggest that breastfeeding women avoid
depoprovera, at least until they have been on the progestin only pill
for a cycle.  That way, if the milk supply starts to decrease, they
can always stop the pill.  You can't take away the depoprovera once
it's injected.

We should also stop looking for quick fixes for the "problem" of
women's fertility.  Each woman needs to have individual counselling
and advice which fits her particular situation.  Breastfeeding is one
of the things that needs to be taken into account.

The problem with depoprovera is that it can be used as a "conveyer
style" approach to birth control.

Jack Newman, MD, FRCPC