Herbal medicine in pregnancy.

Dugoua J-J. 2010. Herbal medicines and pregnancy. J Popul Ther Clin


Pharmacol 17:3;e370-8.

This paper, presented at the Drugs in Pregnancy and Lactation

Symposium in Toronto, Canada in June 2010, reported that the use of

herbal medicines in pregnancy varies enormously dependent on the

geographic area, sociocultural aspects and ethnicity, with figures

ranging from 7% to 55% usage with up to 93% of midwives prescribing or

administering herbal or natural health products (NHPs).

In a study on pharmaceutical drug use by 295 pregnant women, 37%

reported non compliance with their existing medication based on concern

over drug use during pregnancy and the preference for NHPs over

prescription medications. The author stressed the importance of

understanding the potential dangers of NHPs for women of childbearing

age, particularly when trying to conceive.

Evidence based usage for NHPs includes:

* ginger (Zingiber officinale) and vitamin B6 for nausea and

vomiting of pregnancy;

* red raspberry (Rubus idaeus) for shortening the second stage of

labour, lowering the rate of forceps delivery, reducing the likelihood

of artificial rupture of membranes or need for caesarean section;

* castor oil to increase the likelihood of initiating successful

labour within 24 hours;

* probiotics to assist in the prevention of atopic disease in


Evidence for harm from NHPs includes the use of blue cohosh

(Caulophyllum thalictroides) for its reported cardiovascular side

effects in both the pregnant woman and the neonate.

Other evidence presented included:

* echinacea (Echinacea spp) showed no statistically significant

difference between the test group and control group in its effect on

spontaneous abortion or risk of malformation during pregnancy;

* herbs containing berberine (such as Hydrastis canadensis,

Berberis vulgaris, Berberis aquifolium) may displace bilirubin bound to

albumin and aggravate newborn jaundice–this is based only on rat

studies over one week;

* the safety of St John’s wort (Hypericum perforatum) rests on

the case of a woman who started taking St John’s wort at 24 weeks

gestation and developed thrombocytopenia–the author did not attribute

this to St John’s wort;

* further studies on St John’s wort found rates of major

malformations were similar between the test groups of pregnant women on

St John’s wort, pregnant women on antidepressant medications and

healthy pregnant women with no teratogenic exposure during pregnancy.

For approximately 60% of NHPs, safety in pregnancy is unknown

although women continue to initiate taking these products during

pregnancy. To provide best care clinicians must screen their patients

for use of complementary and alternative medicines and stay up to date

on research regarding these agents.

Tessa Finney-Brown MNHAA