Here in Australia we do have access to an excellent reference on herbs:
Herbal Remedies: Harmful and Beneficial Effects by Professor S Talalaj & Dr
AS Czechowicz. It may be possible for you to get it from a specialist and
helpful bookstore in the USA. ISBN 0 85572 189 8. Publisher Hill of
Content.
I've just seen a woman who was told by her local pharmacist to take as much
raspberry tea as she could cope with to help with morning sickness, when
these authors say "powdered leaves in an excessive dose
should be avoided in early pregnancy because they may exert an affect on
the uterus and may even cause an abortion".

Jan Cornfoot
Editor, CAPERS