The mother, even with a baby this old, should avoid estrogens.  I don't
know who got the idea that after 4 months it's okay to use estrogens
with breastfeeding mothers, but I have heard of significantly decreased
supply even with an 8 month old.

It is unlikely the rash is due to the hormones.  The amount that gets
into the milk is very low.  The side effects listed by the manufacturer
are all the side effects ever reported.

Jack Newman, MD, FRCPC