As cited by news services and the original source yesterday,

In a survey of 97 new patients being seen at an infertility clinic, reported in the Australia & New Zealand Journal of Obstetrics and Gynecology [April 2007 issue], Stankiewicz and colleagues discovered that two-thirds reported using complementary medicine.

Nearly half of them said they had consulted with a complementary therapy provider, such as a chiropractor, acupuncturist, or naturopath.

Over three-quarters of the patients reported taking over-the-counter multivitamins, and about a quarter to one-third used herbal remedies including chamomile, echinacea, peppermint, and chaste tree berry.

I know of no scientific association for the use of most of these herbs in infertility except perhaps for chaste tree berry, Vitex agnus castus.

Traditionally used by monks and the clergy to promote celebacy, Vitex has been shown to contain at least one compound with dopamine D2 agonist activity. This is similar to a drug called bromocriptine (Parlodel), whose action on the anterior pituitary gland suppresses production of prolactin. Hyperprolactinemia interferes with ovulation by suppressing release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Bromocriptine, also used to treat Parkinson’s disease, is not as widely used for infertility as it once was, but it is thought to restore the balance between prolactin, LH, and FSH and increasing the chance of proper ovulation.

A well-recognized German endocrine research group isolated dopamine agonists from chasteberry extracts, but this botanical has been studied primary to treat premenstrual syndrome and not as a fertility agent. One concern with its use as a fertility agent is that while Vitex extracts suppress prolactin release in cell culture, the same group has shown there is no resultant effect on LH or FSH.

The authors do have the usual concerns, however,

It’s possible that these therapies may interact with each other and impact the odds of a woman becoming pregnant, experts say, as the safety and efficacy of complementary medicines used to treat infertility or in conjunction with established treatments is unclear.

[...]

It’s been shown that the hormonal effects of chaste tree berry may promote the development of a serious condition called “ovarian hyperstimulation syndrome” in women having in vitro fertilization, Stankiewicz pointed out.

Vitex/chasteberry/chaste tree berry is not an herb whose use is restricted to South Australia and at least one German botanical manufacturer makes a well-characterized and standardized extract and they seem to support clinical trials of their products. However, my primary question in these cases is what might an herbal product offer that other similarly-acting therapies don’t?

In any case, a German-trained MD/PhD family medicine doc at the University of Medicine and Dentistry of New Jersey has a nice, concise, free-access review of chasteberry here.