Objective
Interest in herbal treatments has increased without data on safety, efficacy, or rates of use in pregnancy. We examined antenatal herbal and natural product use among mothers of nonmalformed infants in 5 geographic centers.
Study design
We used data on nonmalformed infants from the Slone Epidemiology Center’s case-control surveillance program for birth defects to examine rates and predictors of herbal use. Exposures were identified through maternal interview. In addition to overall use, 5 categories based on traditional uses and 2 natural product categories were created; topical products and herbal-containing multivitamins were excluded.
Results
Among 4866 mothers of nonmalformed infants, 282 (5.8%) reported use of herbal or natural treatments. Use varied by study center and increased with increasing age.
Conclusion
Although rates of use are low, there remains a need for investigation of the safety of these products. Given sparse data on efficacy, even small risks might well outweigh benefits.
It is widely recognized that use of herbal and complementary medical treatments has increased in the United States over the last decade. While passage of the Dietary Supplements Health and Education Act of 1994 provided some guidelines for these supplements, the legislation included no safety or efficacy standards that must be met and, unlike medications, the Food and Drug Administration does not formally approve dietary supplements prior to marketing.
For Editors’ Commentary, see Table of Contents
While use of these products is believed to be increasing, little is known about their use specifically during pregnancy. A few small studies have considered specific subpopulations and geographic regions, but there are few data available on current use of herbal treatments among the general population of pregnant women in the United States. Knowledge of use is particularly important given that there is some evidence to suggest that anxiety about harming the fetus leads some women to avoid pharmaceutical treatment, and it is possible that they may be substituting herbal products, perceived to be more “natural.” Alternatively, they may be using herbal and other natural products in addition to traditional medications, which raises concerns about possible interactions. Thus, it is important to understand the extent to which herbal and other natural treatments are used in pregnancy, the specific products used, the reasons why they are used, and factors that may predict which women are most likely to use herbal and other natural products. In this article, we examine use in pregnancy of herbal and other natural treatments.
Materials and Methods
The Slone Epidemiology Center at Boston University has been conducting the Birth Defects Study (also known as the Pregnancy Health Interview Study), a form of case-control surveillance to identify the risks and safety of various antenatal environmental exposures, particularly medications, in relation to birth defects since 1976; the methods have been described previously. Since the study’s inception, infants with birth defects have been identified in birth and tertiary care hospitals in various geographic areas, and, since 1993, a sample of nonmalformed infants was also identified at study hospitals in all study centers. Depending on the size of the hospital, between 3–10 nonmalformed infants are selected at random from hospital discharge lists. In 1998, ascertainment of malformed subjects was modified in Massachusetts to involve the state’s birth defects registry system, and an analogous change was made to identify nonmalformed infants from a random sample of birth certificates. The current report is based on mothers of nonmalformed infants included in the study from 5 study centers (greater Philadelphia, PA; greater Toronto, Ontario, Canada; San Diego, CA; and state-based birth defects registries in Massachusetts and New York State) who were interviewed from 1998–2006.
Mothers of eligible subjects are interviewed within 6 months of the baby’s birth by trained nurse-interviewers using a standardized questionnaire. The interview elicits demographic information about the mother and father and detailed information regarding maternal illnesses and medications used from 2 months prior to the last menstrual period (LMP) through the end of pregnancy. This study was approved by Boston University Medical Center’s Institutional Review Board and, as appropriate, the institutional review boards of participating institutions, and informed consent was obtained from all participants.
Information on drug exposures during the time period from 2 months prior to the date of the LMP through the end of pregnancy is elicited through a series of questions designed to maximize recall and accuracy of reporting. We inquire first about illnesses that subjects may have had and any treatments used for them. The women are then asked about common indications for medication use (eg, headache, depression, heartburn, fluid retention), specific medication categories (eg, vitamins, antibiotics, laxatives), and, finally, specific medications (eg, Advil, Tylenol products, Prozac, Allegra). Each of these questions includes the following statement: Please include medications prescribed by a health care provider and medications you may have obtained without a prescription from stores, pharmacies, friends, or relatives, as well as herbal or home remedies. Women who report use of any treatment are asked to retrieve the bottle or package if it is still available.
For this analysis, we considered a product to be “herbal” if it contained ≥1 ingredient that was botanical in origin, regardless of the part of the plant from which the ingredient is derived. We excluded topical treatments and all multivitamins, whether or not they contained an herbal ingredient from the analysis. Because this is a survey of reported use of herbal and other natural products rather than an investigation of risks and safety of specific ingredients, we focused primarily on products rather than specific ingredients, although we also examined 4 ingredients thought to be of particular interest: chamomile, ephedra, ginger, and ginseng.
We created 5 categories of products based on their traditional uses: cough and cold remedies (eg, echinacea, arnica), nausea and vomiting of pregnancy (NVP) (eg, ginger, raspberry), psychiatric and sleep disorders (eg, valerian, Gingko biloba ), weight loss or sports enhancement (eg, Metabolife [Metabolife International, Inc., San Diego, CA], ginseng), and bladder or other “female” problems (eg, chamomile, cranberry juice). We also investigated 2 additional natural product categories: probiotics (eg, acidophilus) and lipids and omega fatty acids (eg, fish oil, evening primrose oil). A given product could be included in >1 of these categories, if appropriate (eg, ginseng is included in both “cough and cold remedies” and “weight loss or sports enhancement”). A woman was considered to be exposed if she reported use of the product at any time from 2 months prior to the LMP through the end of pregnancy; use according to month of gestation was also investigated.
We examined a wide range of potential predictors of use of herbal and other natural treatments in pregnancy: age; ethnicity; education; family income; marital status; body mass index; smoking status; alcohol consumption; coffee and tea consumption; parity; history of chronic conditions, including asthma, diabetes, hypertension, and herpes; conditions occurring during pregnancy, including respiratory infections, morning sickness, urinary tract infections, fevers, and toxemia; use of prescription or nonprescription medications (other than herbal); study center; and LMP year. Multiple logistic regression was used to evaluate each potential risk factor while controlling for the effects of others.
Results
There were 4866 interviews of mothers of nonmalformed infants available for study, with LMP years between 1997–2005. Among women we were able to locate, the participation rate was 68.0%; this rate ranged from 64% in New York to 61% in Massachusetts. Massachusetts subjects represented about 60% of the study sample; Philadelphia, PA, 15%; Toronto, Ontario, Canada, 13%; and the remainder were from San Diego, CA, and New York State. Overall, 282 women (5.8%) reported using an herbal or other natural treatment. As shown in Figure 1 , use varied considerably by center.
Table 1 reveals a clear increase in use with increasing age ( P < .05), but few other factors seemed related to overall herbal and other natural product use. Hispanic women reported more herbal and other natural use compared with whites, but the 95% confidence interval (CI) included 1.0. There was no evidence that use of herbal and other natural products increased over time. Women who experienced NVP or who had a respiratory infection had higher rates of herbal and other natural use than women who did not (see below), and it is interesting to note that women who drank decaffeinated coffee or tea were also slightly more likely to use herbal or other natural products.
| Any herbal use, (n = 282) | ||||
|---|---|---|---|---|
| Women’s characteristics | n | % | Crude OR (95% CI) | Adjusted OR a (95% CI) |
| Age, y | ||||
| <20 | 8 | 2.2 | 0.39 (0.19–0.82) | 0.52 (0.19–1.42) |
| 20–24 | 34 | 5.2 | 0.95 (0.62–1.46) | 0.74 (0.44–1.26) |
| 25–29 (Reference) | 66 | 5.4 | 1.00 (Reference) | 1.00 (Reference) |
| 30–34 | 106 | 6.2 | 1.15 (0.84–1.58) | 1.19 (0.84–1.68) |
| 35–39 | 53 | 6.7 | 1.24 (0.86–1.81) | 1.34 (0.88–2.04) |
| ≥40 | 14 | 13.5 | 2.71 (1.47–5.02) | 2.95 (1.49–5.83) |
| BMI | ||||
| Underweight | 5 | 2.2 | 0.35 (0.14–0.86) | 0.30 (0.11–0.81) |
| Normal (Reference) | 184 | 6.0 | 1.00 (Reference) | 1.00 (Reference) |
| Overweight | 64 | 6.6 | 1.10 (0.82–1.48) | 0.91 (0.66–1.27) |
| Obese | 24 | 4.4 | 0.72 (0.47–1.12) | 0.70 (0.43–1.14) |
| Ethnic background | ||||
| White (Reference) | 205 | 5.8 | 1.00 (Reference) | 1.00 (Reference) |
| African origin | 15 | 4.4 | 0.74 (0.44–1.27) | 1.16 (0.62–2.17) |
| Other | 24 | 6.8 | 1.19 (0.77–1.84) | 1.44 (0.87–2.39) |
| Hispanic | 38 | 6.1 | 1.05 (0.73–1.50) | 1.58 (0.98–2.54) |
| Smokers | ||||
| During pregnancy | 29 | 5.6 | 1.12 (0.74–1.69) | 1.40 (0.85–2.29) |
| Never (Reference) | 142 | 5.0 | 1.00 (Reference) | 1.00 (Reference) |
| Before pregnancy | 111 | 7.3 | 1.48 (1.15–1.91) | 1.31 (0.97–1.76) |
| Education, y | ||||
| <High school | 12 | 2.7 | 0.42 (0.23–0.77) | 0.41 (0.17–1.00) |
| Completed high school (Reference) | 132 | 6.2 | 1.00 (Reference) | 1.00 (Reference) |
| >High school | 138 | 6.0 | 0.96 (0.75–1.22) | 0.85 (0.63–1.17) |
| Income, $/y | ||||
| <10,000 | 8 | 3.4 | 0.54 (0.26–1.12) | 0.80 (0.32–2.05) |
| 10,000–45,000 | 65 | 5.7 | 0.92 (0.69–1.23) | 1.03 (0.71–1.48) |
| >45,000 (Reference) | 190 | 6.2 | 1.00 (Reference) | 1.00 (Reference) |
| Center | ||||
| Boston, MA (Reference) | 133 | 4.5 | 1.00 (Reference) | 1.00 (Reference) |
| Philadelphia, PA | 52 | 6.9 | 1.56 (1.12–2.17) | 1.40 (0.95–2.07) |
| Toronto, Ontario, Canada | 56 | 9.2 | 2.14 (1.54–2.96) | 2.13 (1.49–3.06) |
| San Diego, CA | 37 | 7.8 | 1.80 (1.23–2.63) | 2.23 (1.41–3.52) |
| New York State | 4 | 6.1 | 1.37 (0.49–3.82) | 1.11 (0.32–3.89) |
| LMP year | ||||
| 1997–1998 | 49 | 5.3 | 0.83 (0.55–1.26) | 1.01 (0.62–1.65) |
| 1999–2000 | 96 | 6.6 | 1.05 (0.73–1.50) | 1.20 (0.77–1.87) |
| 2001–2002 | 91 | 5.2 | 0.81 (0.56–1.16) | 0.75 (0.49–1.14) |
| 2003–2005 (Reference) | 46 | 6.3 | 1.00 (Reference) | 1.00 (Reference) |
| Alcohol use | ||||
| During pregnancy | 108 | 7.2 | 1.33 (1.02–1.74) | 1.34 (0.82–1.57) |
| Never (Reference) | 124 | 5.5 | 1.00 (Reference) | 1.00 (Reference) |
| Before pregnancy | 49 | 4.5 | 0.81 (0.58–1.13) | 0.68 (0.46–1.01) |
| Marital status | ||||
| Married (Reference) | 215 | 6.0 | 1.00 (Reference) | 1.00 (Reference) |
| Other | 67 | 5.3 | 0.89 (0.67–1.18) | 1.25 (0.84–1.85) |
| Total pregnancies | ||||
| 1 (Reference) | 72 | 4.8 | 1.00 (Reference) | 1.00 (Reference) |
| 2 | 93 | 6.1 | 1.28 (0.94–1.76) | 1.14 (0.80–1.64) |
| ≥3 | 117 | 6.4 | 1.35 (1.00–1.82) | 1.12 (0.78–1.60) |
| Coffee use | ||||
| Never (Reference) | 80 | 4.4 | 1.00 (Reference) | 1.00 (Reference) |
| Ever | 197 | 6.6 | 0.65 (0.50–0.85) | 1.11 (0.80–1.53) |
| Decaffeinated coffee use | ||||
| Never (Reference) | 161 | 4.9 | 1.00 (Reference) | 1.00 (Reference) |
| Ever | 117 | 7.7 | 0.62 (0.49–0.80) | 1.37 (1.02–1.84) |
| Tea use | ||||
| Never (Reference) | 78 | 3.9 | 1.00 (Reference) | 1.00 (Reference) |
| Ever | 201 | 7.2 | 1.91 (1.46–2.50) | 1.77 (1.30–2.39) |
| Asthma | ||||
| No (Reference) | 271 | 5.9 | 1.00 (Reference) | 1.00 (Reference) |
| Yes | 11 | 4.5 | 1.31 (0.71–2.42) | 1.39 (0.44–4.39) |
| Diabetes | ||||
| No (Reference) | 272 | 5.9 | 1.00 (Reference) | 1.00 (Reference) |
| Yes | 10 | 4.3 | 1.40 (0.73–2.66) | 1.37 (0.49–3.85) |
| Hypertension | ||||
| No (Reference) | 258 | 5.9 | 1.00 (Reference) | 1.00 (Reference) |
| Yes | 24 | 5.1 | 1.15 (0.75–1.77) | 1.77 (0.61–5.18) |
| Herpes | ||||
| No (Reference) | 278 | 5.8 | 1.00 (Reference) | 1.00 (Reference) |
| Yes | 4 | 4.5 | 1.30 (0.47–3.56) | 1.34 (0.32–5.55) |
| Chronic condition | ||||
| No (Reference) | 237 | 6.1 | 1.00 (Reference) | 1.00 (Reference) |
| Yes | 45 | 4.7 | 0.76 (0.55–1.05) | 0.51 (0.17–1.55) |
| Upper respiratory infection | ||||
| No (Reference) | 87 | 4.4 | 1.00 (Reference) | 1.00 (Reference) |
| Yes | 195 | 6.7 | 1.55 (1.20–2.01) | 1.41 (1.04–1.89) |
| Fever | ||||
| No (Reference) | 207 | 5.5 | 1.00 (Reference) | 1.00 (Reference) |
| Yes | 75 | 7.0 | 0.77 (0.58–1.01) | 1.03 (0.76–1.41) |
| Urinary tract infection | ||||
| No (Reference) | 241 | 5.6 | 1.00 (Reference) | 1.00 (Reference) |
| Yes | 41 | 7.2 | 1.30 (0.92–1.83) | 1.42 (0.96–2.10) |
| Toxemia | ||||
| No (Reference) | 275 | 5.8 | 1.00 (Reference) | 1.00 (Reference) |
| Yes | 7 | 5.1 | 0.88 (0.41–1.90) | 0.79 (0.31–2.01) |
| Morning sickness | ||||
| No (Reference) | 91 | 4.8 | 1.00 (Reference) | 1.00 (Reference) |
| Yes | 191 | 6.5 | 1.38 (1.07–1.78) | 1.43 (1.07–1.89) |
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