Ginger (Zingiber officinale), is a well-known remedy for gestational sickness, its antiemetic effects
probably being due to local gastrointestinal anticholinergic and antihistamine actions. Vutyavanich
et al. demonstrated significant improvements in the severity of both nausea and vomiting of
pregnancy, and Fischer Rasmussen et al. found it particularly effective for hyperemesis gravidarum
when compared to placebo. Postoperative nausea and vomiting following gynaecological surgery has
also been alleviated with ginger, although other studies dispute this. Indeed, in some
women, ginger may actually exacerbate nausea andvomiting, and is occasionally accompanied by
heartburn. This exacerbation is thought to result from administration to women whose ‘‘energy’’, in
Traditional Chinese Medicine theory, is too ‘‘Yang’’or hot, with ginger being considered a ‘‘hot’’
remedy; these women usually respond well to peppermint.It is possible that certain constituents of Z.
officinale are mutagenic while other constituents may have a reverse effect. Wilkinson identified
an increased embryo loss in rats given ginger,although a similar study29 found no maternal or
fetal developmental toxicity, and no adverse effects in human pregnancy have been reported.28
Fetal effects may be dose dependent and caution suggests maintaining doses at a maximum of one
gram per day. Potentiation of anticoagulants by ginger is possible, probably due to antiplatelet effects,
although the evidence appears to be insufficient to determine practice guidelines.However, regular
assessment for coagulation disorders in patients taking ginger over a prolonged period may be
wise, although as there does not seem to be an effect on gastric emptying the possibility of
interactions with drugs influenced by gastrointestinal transit time theoretically does not exist.
St. John’s wort (Hypericum perforatum) has been one of the most publicised herbal medicines
in recent years and is well-known for treating mild to moderate depression, including premenstrual
or menopausal symptoms, but its value for severe depression is unconfirmed. Side effects include allergy, photosensitivity in fair skinnedpeople, gastrointestinal disturbance,fatigue, anxiety and panic attacks.Iron absorption
may be inhibited by the presence of tannins,predisposing women to anaemia, while more serious problems include mania and sub-acute toxic neuropathy.Expectant mothers with normal hormonal mood swings, and newly delivered women with a history of previous postnatal depression may self-administer St. John’s wort or ask maternity staff about its
use. Pregnant women and those attempting to conceive should be advised to discontinue use of St. John’s wort, as damage to oocytes may occur in high concentrations, (as also with echinacea and Ginkgo biloba) and sperm motility may be inhibited in men, although studies on the neurobehavioural development of mice exposed to hypericum found no long-term adverse effects. Its use during breastfeeding, as a preventative for postpartum depression, appears acceptable but no long-term studies of its effects on the infant have yet been undertaken.