Medicines Q&As
Q&A 92.3
Is it safe to take herbal medicines during pregnancy?
Prepared by UK Medicines Information (UKMi) pharmacists for NHS healthcare professionals
Before using this Q&A, read the disclaimer at www.ukmi.nhs.uk/activities/medicinesQAs/default.asp
Date prepared: 1st March 2012
Background
A recent observational cohort study in South West England found that 26.7% (n=3774) of women had
used a complementary or alternative medicine at least once during pregnancy; the use rising from 6%
(n=824) in the first trimester to 12.4% (n=1639) in the second and to 26.3% (n=3269) in the third (1).
Only 7.6% (n=1073) of women did not take any medicinal product (conventional or complementary)
throughout the whole of their pregnancy. The most common herbal products were chamomile,
peppermint, raspberry leaf and rosehip. Use of complementary medicines increased with age of the
mother, with older mothers more likely to have used a complementary medicine than younger
mothers (43.5% aged over 35 years and 15.2% aged 24 years or under) (1). Another United Kingdom
(UK)-based study reported 57.8% (n=334) of women used herbal remedies during pregnancy, with a
mean of 1.2 remedies (range 0-10) per woman. The most commonly used remedies were ginger,
cranberry and raspberry leaf (2). Of some concern is that 76% of the pregnant women reported not
informing their doctor or midwife that they were using herbal medicines, and that family or friends
were the most frequently cited source of information about herbal remedies during pregnancy (2).
One recent survey involving 600 postpartum women in Norway found that 39.7% had used herbal
medicines during pregnancy with an average of 1.6 products per woman. Echinacea, iron-rich herbs,
ginger, chamomile and cranberry were the most commonly used herbal medicines (3).
Evening primrose oil, ginseng, green tea, flax and valerian are also reportedly commonly used by
women during pregnancy (4-6).
Herbal medicines are often mistakenly viewed as natural and safe alternatives to conventional
medicines. Unfortunately, some plants have toxic constituents and many have constituents with
pharmacological activity, such as stimulation of uterine muscle, which could render them unsuitable
during pregnancy (7). Contamination with substances such as pesticides, conventional medicines or
heavy metals cannot be ruled out. In fact there is a case report of a preterm infant found to have
elevated blood lead levels as a result of the long-term ingestion of lead-contaminated herbal
medicines by the mother (8). Preparations often differ with regard to the concentration and origin of
their constituent herbs (9). Furthermore, many modern herbal preparations are available as highly
concentrated extracts, the effects of which could differ substantially from those of more traditional
preparations such as teas made from the leaves of herbs. Therefore the assumption should not be
made that a preparation will be safe merely because its main herbal ingredient has been used during
pregnancy for many years without apparent ill effect (9). As with conventional drugs, the route of
administration (e.g. oral, rectal or injectable) should be considered when determining the safety of an
herbal medicine. Finally, any assessment of risk should take into account potential interactions
between the herbal preparation(s) and any conventional medicine(s) a women is taking, as well as
her past obstetric history and general health.
Answer
Few scientific studies have looked at the effects of herbal medicines in pregnant women and literature
reporting the outcome of pregnancies during which herbal medicines were used is limited. Because of
the scarcity of relevant safety information, use of herbal medicines during pregnancy cannot be
recommended. Despite this, it is clear that many pregnant women use herbal preparations,
particularly for pregnancy-related symptoms. The following information covers the herbal medicines
most likely to be in common usage by pregnant women.
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Medicines Q&As
Blue Cohosh
Blue cohosh has traditionally been used to induce labour (10). There are three case reports in the
literature of potential adverse effects in the neonate following maternal exposure to blue cohosh
around the time of delivery. In the first case stroke was reported in a neonate whose mother had
taken a tea made of blue cohosh (11). The tea was found to contain a metabolite of cocaine and the
authors noted that maternal use of cocaine is a cause of perinatal stroke. It is unclear if the cocaine
metabolite was also a metabolite of blue cohosh or a contaminant in the tea. No follow up details are
provided for this case. In the second case report a neonate experienced a myocardial infarction
associated with congestive heart failure and shock (12). The mother had taken three times the
recommended daily amount of blue cohosh tablets for three weeks to induce labour. The authors
state that other causes of myocardial infarction were ruled out. The infant went on to recover though
some cardiac symptoms persisted at 2 years of age (12). In the third case severe multi-organ hypoxic
injury was reported in a neonate whose mother had taken a blue and back cohosh herbal mixture
(13). At three months there was lower limb spasticity and the infant required nasogastric tube feeding
(13). In vitro evidence suggests that blue cohosh may have teratogenic, embryotoxic and oxytoxic
effects (14). There have been calls for tighter control of its use and for further investigations into its
safety (14).
Chamomile
Traditionally, chamomile is used as a mild sedative and to aid digestion (3), and has reportedly been
used for the treatment of morning sickness (15). There are two types of chamomile – German and
Roman. German chamomile is the type used most often as a medicinal herb. Extracts of German
chamomile have been reported to increase the tone of uterine muscle (16). There is a documented
case in which a 35-year-old woman received an enema made from German chamomile and
experienced life-threatening anaphylaxis; her baby experienced severe asphyxia and died the
following day (17, 18).
Two cases of premature constriction of the foetal ductus arteriosus have been reported following the
maternal consumption of chamomile herbal tea (19). The first patient reported drinking chamomile tea
on a regular basis. A constricted ductus arteriosus and increased blood velocity across it was seen at
20 weeks’ gestation on foetal echocardiography, including Doppler velocity. The patient was advised
to stop drinking the tea and re-assessed one week later, which revealed complete resolution of ductal
constriction with no acceleration in blood flow velocity across the ductus arteriosus (19). The second
case was referred for foetal cardiac assessment at 35 weeks’ gestation on suspicion of foetal
tachycardia. Doppler imaging confirmed high diastolic flow velocities with a pattern consistent with
ductal constriction. The patient confirmed intermittent consumption of chamomile tea during
pregnancy, including about 48 hours before the scan (19). The authors have postulated that ductal
constriction associated with the consumption of chamomile tea is likely to be produced by a similar
pharmacological mechanism to that observed with non-steroidal anti-inflammatory drugs, due to its
inhibitory effects on the cyclo-oxygenase and lipo-oxygenase pathways of arachidonic acid
metabolism (19).
Abortifacient effects have been attributed to orally administered Roman chamomile at medicinal
doses (20, 21).
Both types of chamomile should be avoided during pregnancy until further information is available (15).
Cranberry
Cranberry is used orally to prevent and treat urinary tract infections (22). Reliable scientific
information on the use of cranberry during pregnancy is not available (22, 23). Cranberry at the doses
normally found in foods are not known to cause problems in pregnancy, but medicinal doses of
cranberry should be avoided by pregnant women (24).
Echinacea
Echinacea is commonly used orally to treat and prevent the common cold and other upper respiratory
infections (25). Only one prospective study (26) has looked at pregnancy outcome after gestational
Available through NICE Evidence Search at www.evidence.nhs.uk
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exposure to echinacea. The study included 412 pregnant women who had contacted a teratogen
information service to ask about the safety of echinacea for an upper respiratory tract illness. The
study group comprised those who went on to take echinacea (n=206), whereas those who chose not
to use it or used a non-teratogenic antibiotic instead formed the control group (n=206). In the study
group, use of echinacea was generally for between five and seven days and 54% (n=112) of women
used echinacea during the first trimester. The groups did not differ statistically significantly with regard
to pregnancy outcome, delivery method, gestational age, birth weight or foetal distress. In the study
group, 6 major and 6 minor malformations occurred and in the control group there were seven major
and seven minor malformations. As the authors noted, limitations of the study included the small
sample size and lack of standardisation of doses (tablets, capsules and tinctures in varying doses
were used) (26). Further evidence of the safety of echinacea during pregnancy is required (27, 28).
Evening Primrose Oil
Midwives reportedly use evening primrose oil to expedite cervical ripening, in an attempt to shorten
labour and reduce the incidence of postdate pregnancies (29). One study compared outcomes in 54
women who took evening primrose oil orally from week 37 of pregnancy with those in 54 women who
did not. No difference in the overall length of labour was found between groups. Further, it was
concluded that women taking evening primrose oil might be more likely to experience prolonged
rupture of membranes, oxytocin augmentation, arrest of descent and vacuum extraction (29).
One report was found of ecchymoses and petechiae on the trunk, extremities and face of a female
baby, aged 17 hours. The infant had no other symptoms. In the week before delivery her mother had
taken raspberry leaf tea and a total of thirteen 500mg capsules of evening primrose oil, vaginally and
orally, in an attempt to improve labour. The authors suggested that the evening primrose oil had
inhibited platelet function in the newborn infant. The platelet count was reported as normal in the
infant and her symptoms resolved spontaneously by day 5 (30).
Flax
There is very little information on the effects of flax during human pregnancy, but it might have
oestrogenic effects, which would be a cause for concern in a pregnant woman (31). One study found
that flax use during the last two trimesters of pregnancy was associated with an increased risk of
preterm birth (32).
Ginger (root)
Between 50 and 80% of women experience nausea during pregnancy (33). A Cochrane review on
interventions for nausea and vomiting during pregnancy concluded that the use of ginger may be
helpful to women, but the evidence of effectiveness was limited and inconsistent (33). The current
National Institute for Health and Clinical Excellence (NICE) guidance on antenatal care highlighted
that ginger appears to be an effective intervention in reducing nausea and vomiting symptoms in early
pregnancy (34).
A study conducted in Thailand compared oral ginger (1g/day for 4 days, n=32) with an identical
placebo (n=35). These women were at week 17 or an earlier stage of their pregnancy (35). The
primary outcome was improvement in nausea symptoms and this was measured using a visual
analogue scale and a Likert scale. Overall, the number of spontaneous abortions (miscarriages) did
not differ statistically significantly between groups (3 in placebo group, 1 in ginger group, p=0.615)
There were no reports of congenital anomalies in the infants (35), but the lengths the investigators
went to in order to identify such anomalies is not clear from the published paper (35). It should also be
noted that the patient population was small in this study and it is generally easier to identify a pattern
of anomalies within a larger patient population.
This trial was among six double-blind randomised controlled trials (RCTs) (n=675) and one
prospective observational cohort study reviewed in a publication investigating the efficacy and safety
of ginger for pregnancy-induced nausea and vomiting (36). Ginger doses in the trials ranged from
125mg ginger extract four times a day to 500mg three times a day. The prospective observational
cohort study involved 187 women exposed to ginger during the first trimester of pregnancy and 187
women exposed to non-teratogenic drugs. Dosage and origin of the ginger were not documented. No
statistically significant differences were noted between the two groups for live births, spontaneous
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abortions, still births, therapeutic abortions, birth weight or gestational age. Follow-up of four of the
reviewed RCTs found ginger to have no significant adverse effects on pregnancy outcome. Adverse
effects taken into account included antepartum haemorrhage, pre-eclampsia, preterm birth, perinatal
and neonatal death and congenital abnormalities (36).
The authors of a single-blind study in 67 pregnant women who complained of nausea and vomiting
suggested that a dose of 250mg ginger four times a day taken for 4 days can be an effective means
of decreasing nausea and vomiting of pregnancy (37).
A double-blind, randomised controlled trial lasting seven days in 170 pregnant (<16 weeks gestation)
women indicated that ginger 500mg twice daily is as effective, but slower than dimenhydrinate 50mg
twice daily to take effect in the treatment of nausea and vomiting during pregnancy. Over the course
of the study, the mean nausea score (measured by participants using a visual analogue scale)
decreased in both groups, but no statistically significant difference in score was seen between the two
groups. Drowsiness and heartburn were noted in both groups, the incidence of drowsiness being
significantly higher in the dimenhydrinate group (78% versus 6%, p<0.01). No additional adverse
effects are reported but follow up was only for one week (38). Dimenhydrinate is only available in the
UK in combination with cinnarizine in a preparation licensed to treat vestibular disorders in adults (39).
Ginger 650mg three times a day was found to be more effective than vitamin B6 25mg three times a
day in 123 pregnant (≤16 weeks gestation) women. Participants in this study received their treatment
at home for four days and then returned to antenatal clinic for follow up. Side-effects reported in the
ginger group were heartburn (n=8), sedation (n=7) and arrhythmia (n=1) (no further details reported).
Two and eleven patients in the vitamin B6 group also experienced heartburn and sedation,
respectively (40).
Concern has been raised that the thromboxane synthetase inhibitory action of ginger could affect
testosterone receptor binding (41) thereby possibly altering sex steroid differentiation of the foetal
brain (42). Ginger also has limited potential to stimulate uterine smooth muscle (43). Despite these
theoretical concerns, the risk posed by ginger to the foetus is considered to be low (41), particularly
when it is used at the doses found in foods (43). However, it has been suggested that doses of ginger
higher than 1g/day should be avoided during pregnancy (43).
Ginseng (Panax)
Little information is available on the safety of ginseng during pregnancy in humans (or animals) and
further data are warranted (44). In non-pregnant patients, hypertension and hypoglycaemia have
been reported with ginseng and these effects could complicate pregnancies with hypertensive
disorders or diabetes (44). It is possible that ginseng has oestrogen-like properties (45) and is
therefore not recommended during pregnancy (46).
A study in which 88 women who had taken ginseng during pregnancy were matched with 88 controls,
found no statistically significant differences between groups in birth weight, mode of delivery, preterm
delivery, low Apgar scores, stillbirths or neonatal death. No mention was made of congenital
malformations (47).
Pregnancy outcome was reported for 149 cases of exposure to ginseng during the first trimester of
pregnancy (48). In 116 of these cases, foetal exposure was to ginseng alone. Of the children born to
women who had taken ginseng alone during the first trimester, six had malformations, but evaluation
by individual defect category did not indicate that the risk of malformation was significantly higher than
that in a control group in which herbal medicines had not been used (48,49). It is interesting to note
that in traditional Chinese medicine ginseng is contraindicated in pregnant and lactating women
except in the treatment of specific conditions (49).
There is one report of androgenisation in a neonate exposed to ginseng in the womb and through
breastfeeding (50), however the cause of the androgenisation was later reported to be most likely
caused by the mother taking Periploca sepium (silk vine) rather than ginseng (51). Therefore causality
has not been established.
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Green Tea
There is limited evidence regarding the use of green tea during pregnancy (52, 53). Large quantities
of green tea should be avoided by pregnant women because of their caffeine content (53). Caffeine
crosses the placenta producing foetal blood concentrations similar to maternal levels (53). The Food
Standards Agency advises pregnant women not to consume more than 200mg caffeine per day
because higher caffeine intakes might cause miscarriage or low birth weight (54).
Iron-rich herbs
During pregnancy the need for iron increases and may not be sufficiently covered by food or maternal
iron stores (55). Several different preparations of iron-rich herbs are available. The quantity of iron
found in these products may vary greatly and the risk of contaminants cannot be ruled out. If a
patients thinks they may be iron deficient then this should be verified by their doctor who can
prescribe appropriate treatment.
Peppermint
Some sources suggest that peppermint in large doses during pregnancy might have an
emmenagogue (stimulating menstruation) and abortifacient effect (56, 57). Peppermint has been
traditionally used for hundreds of years; one source suggests that in the absence of medical literature
reporting adverse effects, that there is little risk from the typical use of this herb in pregnancy (57).
Raspberry leaf
Raspberry leaf is used by women during pregnancy for morning sickness and to shorten and facilitate
labour (58). Raspberry extract has been reported to cause contractions in strips of healthy human
pregnant uteri but not in strips of human non-pregnant uteri (59). Raspberry leaf might have
oestrogenic effects and uterine smooth muscle is reportedly either stimulated or contracted by
different raspberry leaf constituents (58). The safety of raspberry leaf during pregnancy was
investigated in a prospective, randomised, controlled study (60) and a retrospective record review
study (61). The prospective study required 240 nulliparous women to take raspberry leaf tablets (2 x
1.2g/day) (n=96 completed study) or placebo (n=96 completed study) from gestational week 32 until
labour; whereas in the retrospective study, the women who took raspberry leaf (n=57; n=51 in control
group) started as early as week 8 of their pregnancy. In the retrospective study, a variety of raspberry
leaf preparations were taken, e.g. tea, tablets and/or tincture. Neither study showed a significant
difference in efficacy between groups in the first, second or third stage of labour. With regard to
safety, both studies found neither maternal nor infant safety to be affected by raspberry leaf
consumption. Neither study found a difference between the two groups in the occurrence of
meconium-stained amniotic fluid (60, 61); presence of meconium in the amniotic fluid would indicate
that the baby was under stress (62). Maternal and infant safety measures differed between the
studies, but both took into account maternal blood loss at birth, maternal diastolic blood pressure
(timings different in each study), and the occurrence of side-effects in study participants, newborn
admission to a neonatal unit/special care baby unit and newborn Apgar score at 5 minutes. However,
these studies were not large and may not have detected rare effects. Raspberry leaf does not appear
to reduce the length of labour or decrease the need for analgesics in the perinatal period (58).
A recent Norwegian study highlighted a significant association between the use of raspberry leaves in
pregnancy and caesarean delivery (23.5% versus 9.1% amongst women with no use of herbal drugs
[adjusted OR 3.47, 95% CI 1.45-8.28]) (3). However, current NICE guidance on caesarean sections
supports the findings of the previously mentioned retrospective study (61) and indicates that the use
of raspberry leaf during pregnancy has not been shown to influence the likelihood of caesarean
delivery (63).
In a talk on herbal counter prescribing, details were given of one case of premature labour in a
woman who had taken raspberry leaf since the second trimester of her pregnancy (64). The baby was
born nearly three months before term and the case was reported at the time to the Committee on
Safety of Medicines (CSM), now the Commission on Human Medicines (CHM). Raspberry leaf should
therefore be avoided during early pregnancy. Refer also to evening primrose oil section of Q&A.
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Medicines Q&As
St John’s Wort
A common herbal treatment option for depression, there is little evidence to support the safe use of St
John’s Wort in pregnancy. In their clinical guidelines on the management of depression, NICE advise
that St John’s Wort should be avoided (65). However, unintentional exposure to St John’s Wort during
early pregnancy may occur. One study followed 54 St John’s Wort exposed pregnancies (49 exposed
during the first trimester) and compared the outcomes to those of 54 pregnancies in which the foetus
was exposed to conventional antidepressants, and 54 pregnancies in which the mothers were not
known to suffer from depression or to take any teratogenic drugs (66). Rates of major malformation
were not significantly different between the groups (5% (St John’s Wort group) versus 4% (diseasematched group) and 0% (healthy group) p=0.26). Similarly, there were no significant differences
between groups in terms of foetal outcome (p=0.28), preterm delivery (p=0.10) or birth weight
(p=0.51) (66). Though these results are encouraging further large scale studies are required.
A literature report revealed two cases of exposure to St John’s Wort in pregnancy, only one of which
provides any outcome data in the infant. A 38 year old woman took 900mg/day of St John’s Wort from
week 24 of her pregnancy until 24 hours prior to delivery. The woman breast fed and restarted the St
John’s Wort at 300mg/day on day 20. Behavioural assessments of the neonate at 4 and 33 days were
within the normal range (67).
Valerian
Valerian is used as a sedative and hypnotic for anxiety, restlessness and sleep disturbances (68).
There is little scientific evidence to support the use of valerian during human pregnancy (68, 69) and
therefore its use by pregnant women is not recommended (70, 71).
Other herbal medicines
A prospective cohort of pregnant women of 26 weeks or greater gestation were entered into a hospital
study in Taiwan to estimate the risk of major congenital malformations following herbal use in the first
trimester. A total of 14,551 live births were analysed. 16.9% of mothers had taken any herbal
preparation in the first trimester; An-Tai-Yin and huanglian were the most commonly used, 11.4% and
1.5%, respectively. Adjusting for confounding factors, taking huanglian during the first trimester was
associated with an increase risk of congenital malformation of the nervous system (OR 8.62, 95% CI:
2.54 to 29.24) and increased risk to external genital organs (OR 3.82, 95% CI: 1.18 to 12.40). An-TaiYin was associated with an increased risk of muscle and connective tissue (OR 1.61, 95% CI: 1.10 to
2.36) and eye congenital malformations (OR 7.30, 95% CI: 1.47 to 36.18). Pre-existing maternal
disease was not found to affect these results with the possible exception of huanglian and its effects
on external genital organs. Limitations of the study included only assessing live born infants and lack
of standardisation of the herbal products consumed by the mothers (48).
In their report on the safety of herbal medicines (2002), the Medicines Control Agency (now the
Medicines and Healthcare Products Regulatory Agency [MHRA]) lists herbal ingredients that should
be avoided or used with caution during pregnancy (72).
This report can be accessed via the following link on the MHRA website:
(http://www.mhra.gov.uk/home/groups/es-herbal/documents/websiteresources/con009293.pdf). It
draws attention specifically to the following herbs:


Herbs containing volatile oils that are irritant to the genito-urinary tract: ground ivy,
juniper, parsley, pennyroyal, sage, tansy and yarrow (Also see practical advice below)
Herbs with documented stimulant/spasmolytic action on uterine muscle: blue cohosh
(see above), burdock, fenugreek, golden seal, hawthorn, Jamaica dogwood, motherwort,
nettle, raspberry (see above), vervain (72).
The MHRA also warn that some herbal teas contain laxatives such as senna, frangula and cascara
(72). This is of note in pregnancy because the effects of these herbs may generate contraction of
uterine smooth muscle.
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Medicines Q&As
Suspected adverse reactions (including congenital abnormalities) associated with maternal use of
herbal or complementary medicines should be reported to the MHRA and CHM via the yellow card
reporting system.
Practical Advice
Herbs that are commonly used in cooking would not be expected to be harmful during pregnancy in
the quantities usually contained in foods (43). However, even culinary herbs such as sage, garlic and
turmeric may be associated with risks if they are taken in large doses or concentrated forms (43). The
following advice may be of use to women planning to take herbs at medicinal doses:






Avoid medicines (herbal or conventional) during pregnancy unless they are considered to be
essential.
Seek the advice of a healthcare professional (midwife, doctor or pharmacist) if you are
considering taking herbal medicines. If you decide to take herbal medicines during pregnancy,
ensure that the healthcare professionals involved in your antenatal care are aware of any herbal
medicines that you are taking, or changes in your medication.
If you do decide to take herbal medicines, choose products from a reputable source and follow
the manufacturer’s instructions, especially the dosage advice.
Remember that most herbal medicines have often not undergone rigorous testing before being
made available. There might be little or nothing known about their effects during pregnancy.
Therefore, it is important that you tell your healthcare provider if you feel unwell when taking these
products.
Herbal medicines might have contaminants such as heavy metals, pesticides or conventional
medicines, some of which could be harmful to your unborn child.
Herbal medicines have the potential to interact with any conventional medicines you are taking,
which may make you feel unwell and effect how well your conventional medicine works.
It is important for healthcare professionals to take into consideration why a woman wishes to take an
herbal medicine. Undiagnosed illness that remains untreated by conventional methods might result in
maternal and foetal toxicity.
Healthcare professionals can contact the UK Teratology Information Service on 0844 892 0909 for
assistance in making a patient-specific risk assessment where exposure to herbal medicines has
occurred.
Summary
Recent surveys in the UK suggest that many women in the United Kingdom use herbal medicines
during pregnancy. Herbal medicines are not necessarily safe alternatives to conventional medicines
during pregnancy. Their constituents are likely to have pharmacological activity and they might
possess toxic constituents. Contamination cannot be ruled out and different products often vary with
regard to the concentration and source(s) of their constituent herbs. The way in which an herbal
medicine is administered might affect its safety, e.g. as a tea or concentrated extract, orally or by
injection. Possible interactions with any conventional treatment should be taken into account.
In general, herbal medicines should be avoided by pregnant women. Women who wish to take herbal
products during pregnancy should consult a healthcare professional when considering the risks and
benefits involved. Healthcare professionals should consider why a woman wishes to take an herbal
medicine. Undiagnosed illness that remains untreated by conventional methods might result in
maternal and foetal toxicity.
Any herbal medicines taken should be from a reputable source and taken at the recommended
dosage.
Suspected adverse reactions (including congenital abnormalities) following maternal exposure to an
herbal or complementary medicine should be reported via the yellow card system.
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Medicines Q&As
Healthcare professionals can contact the UK Teratology Information Service for assistance in making
a patient-specific risk assessment where exposure to herbal medicines has occurred.
Limitations
The information above is predominantly concerned with the safety, rather than the efficacy of herbal
medicines during pregnancy. Only limited relevant information on the safety of herbal medicines in
pregnancy is available at present. Herbal products vary considerably with regard to their
concentration, potential toxicity, constituents and the sources of their constituents.
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Quality Assurance
Prepared by
Anna Burgess, Welsh Medicines Information Centre, University Hospital of Wales (based on earlier
work by Alex Bailey)
Date Prepared
1st March 2012
Checked by
Gail Woodland, Welsh Medicines Information Centre, University Hospital of Wales
Date of check
5th March 2012
Search strategy
 Embase ([herbal medicine OR medicinal plant] AND [pregnancy OR congenital malformations/si]
Limit year: 2009 to current)
 Medline ([exp plants, medicinal OR exp drugs, Chinese herbal OR phytotherapy OR exp
angiosperms] AND [pregnancy outcome OR exp abnormalities, drug-induced] Limit year: 2009 to
current)
 In-house database (“herbal medicines” AND pregnancy)
 NeLM (“herbal medicines” AND pregnancy)
 IDIS ([DR]herbal medicines 92510000 OR Chinese herbal medicines 92510129 AND [DI]
pregnancy nec 22 OR [DE] side ef fetal effect 48. Limit year: 2009-2012)
 Micromedex (pregnancy) (herbal medicine name)
 Natural Medicines Comprehensive Database (herbal medicine name)
 Herbal medicines online (herbal medicine name)
 United Kingdom Teratology Information Service (UKTIS), Regional Drug and Therapeutics
Centre, Newcastle upon Tyne
 NICE (herbal medicine name)
Available through NICE Evidence Search at www.evidence.nhs.uk
11