Herbal Medicines in Pregnancy and Lactation: An Evidence-Based Approach PDF

PREFACE

Exposures to over-the-counter products are frequent in pregnant women. Perhaps this is a paradoxical response to the decreased use of prescribed medications during pregnancy for fear of teratogenicity. For many women, natural health products such as herbal medicines or supplements may seem a reasonable alternative as the lay media often portrays natural medicines as safe. While the true incidence of natural product use in pregnancy is not known, some studies suggest that as high as sixty percent of pregnant women use natural therapies including herbal medicines either during pregnancy or while planning.¹ Pregnant women often consider the use of natural products such as peppermint tea or ginger to help with symptoms of pregnancy such as nausea and vomiting.² In one study of midwives practicing in North Carolina, half of the respondents admitted to recommending herbal medicines to their patients for pregnancy related conditions. ³ Further to this intended use, it must be remembered that nearly half of all pregnancies are unplanned and unexpected exposures to medicines and supplements in the first trimester are not rare.

Despite the prevalent use of natural health products by pregnant women, there is very little published evidence with regards to the safety and efficacy of natural health products during pregnancy and lactation. Many modern and classic texts warn against the use of natural product supplementation during pregnancy or lactation for up to one-third of the products listed in their monographs. However, most resources provide little information on the data used to evaluate reproductive toxicity apart from reports of historical use of herbs as abortifacients or uterine stimulants or animal data of genotoxicity or teratogenicity. Data on efficacy during pregnancy is similarly scarce from most texts.

To our knowledge, ours is the first text that aims to specifically address the lack of data of natural health product use in pregnancy and lactation. While it is not an exhaustive compendium of available supplements, it is a comprehensive listing of common herbs, vitamins and supplements used by pregnant women. Drawing on all available studies obtained through meta-analytic techniques, we have graded the quality of evidence on natural product safety during pregnancy and breastfeeding. Statements in traditional texts such as ‘use of this herbal product should occur only after careful assessment of the benefits and risks' need clarification with up-to-date evidence from the medical literature. Busy healthcare providers need to have access to quick and reliable information they can use to help address patient concerns with regards to natural health product use in pregnancy or lactation. We hope that this text will be received as a valuable resource for all clinicians who treat pregnant patients. As natural health supplements continue to gain popularity, we anticipate that the utility for a text such as this will grow too.

1. Maats FH, Crowther CA. Patterns of vitamin, mineral, and herbal supplementation use prior to and during pregnancy. Aust NZ J Obstet Gynaecol 2002; 42:494–496.

2. Hollyer T, Boon H, Georgousis A, Smith M, Einarson A. The use of CAM by women suffering from nausea and vomiting during pregnancy. BMC Complementary and Alternative Medicine 2002; 2:5

3. Allaire AD, Moss M-K, Wells SR. Complementary and alternative medicine in pregnancy: a survey of North Carolina certified nurse-midmives. Obstet Gynecol 2000; 95:19–23.