"Natural" progesterone: information on fetal effects.
BACKGROUND
A variety of progestational agents have been used therapeutically and evaluated for adverse effects over the last 50 years. However, progesterone itself has come into use as a therapeutic agent only recently with the development of an orally bioavailable "micronized" preparation.


METHODS
The current review examines progesterone adverse effects as identified in the larger literature on the toxicity of progestational agents and pharmacokinetics.


RESULTS
Progesterone has cytoplasmic and membrane receptors in a variety of reproductive and nonreproductive tissues including the brain and is a potent inhibitor of GnRH. Limited information is available on progesterone receptors and actions in the fetus. Concern about exogenous progestagen effects on fetal reproductive tract development have led to considerable human research over the years, but this literature review demonstrates that contemporary developmental toxicology research on progesterone is lacking.


CONCLUSIONS
Progesterone is a potent, multi-faceted endocrine agent with an expanding therapeutic profile and a minimal scientific database for evaluating safe use during pregnancy.
Golub
Mari S
MS
Reproductive and Cancer Hazard Assessment Branch, Office of Environmental Health Hazard Assessment, California Environmental Protection Agency, Sacramento, California, USA. mgolub@oehha.ca.gov
Kaufman
Farla L
FL
Campbell
Marlissa A
MA
Li
Ling-Hong
LH
Donald
James M
JM
D000728:Androgens / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D004622:Embryo, Mammalian / Q000187:drug effects* / Q000196:embryology*; D047109:Fetal Development / Q000187:drug effects*; D005333:Fetus / Q000187:drug effects*; D006801:Humans; D011374:Progesterone / Q000009:adverse effects* / Q000378:metabolism / Q000493:pharmacokinetics
D000728:Androgens; D011374:Progesterone