An Evidence-Based Guide to Herb Safety During Pregnancy & Lactation

An Evidence-Based Guide
to Herb Safety During
Pregnancy & Lactation
Jillian Bar-av, MS, RH(AHG), CNS
[email protected]
Should herbs be used during
pregnancy and lactation?
• Some say no
• Some say yes
• Some say only if the benefit outweighs the
What do we mean by herb use?
• Herbs in food
• Beverage herbal teas
• Herbs as medicine
• Even herbs that are considered safe and
used as spices have dosage restrictions:
• Pregnant woman’s physiology is different
from non-pregnant woman
– Due to cardiovascular and renal changes, she is
able to see benefit from smaller doses
Not all stages of pregnancy
and lactation are the same
• Cautions necessary in 1st trimester due
to fetal development of central nervous
system can be relaxed in later
• Cautions necessary in early lactation
can also be relaxed later on
Product quality
• No matter what herb is being taken
while pregnant or breastfeeding, the
quality must be known
• Products that have been adulterated
can obviously be dangerous
Hairy Baby Case
• A woman thought she was taking ginseng throughout
her pregnancy
• She was taking 2x the suggested dose on the label
• She developed signs of androgenization
• The baby was born with significant hirsutism
• It was reported as a ginseng adverse effect
• The label showed that the product actually contained
Siberian ginseng (Eleutherococcus senticosus)
• The product was also adulterated with Periploca
sepium, although in vitro studies did not show it to
have androgenic activity
Prudent Practitioner Guidelines
• Avoid herbs during 1st trimester
– Including most fertility herbs
– beverage/nutritive teas and herbs as
spices/seasoning are generally ok
• Only use herbs when the benefit outweighs
the risk
– Examples
When medication would be riskier to fetus than herbs
Health of mother is jeopardizing health of fetus
Miscarriage prevention
Medication would mean early weaning
Purpose of the Guide
• Create a guide that is actually useful for
– Warnings to use “only under the guidance of a
qualified practitioner” are useless to
– We are the practitioners!
• Though we also need to understand our limitations
Principles of the Guide
• Err on the side of caution, but allow for
• Blend information from the most reputable
sources on the subject
– scientific findings
– traditional use
– clinical experience of modern herbalists/midwives
Rating System of the Guide
• Simple, clear, easy to use at-a-glance
• Categories are for actual use
– Safe
– Restricted use
– Contraindicated
• Clear reasons for ratings with references
Ratings distinguish between
pregnancy & lactation
• Often sources will say “contraindicated during
pregnancy and lactation due to hormonal
– What type of hormonal influence?
– If it is oxytocic, would it really be contraindicated in
both pregnancy and lactation?
• Oxytocin is the hormone responsible for labor induction and therefore
oxytocic herbs should be avoided during pregnancy, unless being used
to assist labor
• Oxytocin is also the hormone responsible for the milk ejection reflex
(MER), therefore herbs that influence oxytocin may be indicated as
Ratings: Disagreements
• If sources disagreed on the safety of the herb,
it was usually given a P2 or L2 rating
• In some cases a choice was made to rate the
herb as safe or contraindicated even when
sources disagreed
– Based on quality of evidence
– Peer practitioner feedback
• Contradictory information is always included
P2 & L2 Ratings
1. Unsafe for internal use, but safe for external
2. Unsafe during 1st trimester, but can be used
in later pregnancy
3. Herbs that are only used during labor
4. Herbs that are only used for miscarriage
prevention or pre-term contractions
5. Unsafe during early breastfeeding, but safe
for later stage breastfeeding
6. Lack of data
7. Practitioner judgment required
• Each herb was looked up in each of 13
• Information from one source may not
have been included if:
– information from one of the other sources
obviously surpassed it in thoroughness and
– it was referencing one of the other sources
American Herbal Products Association’s
Botanical Safety Handbook
Michael McGuffin, Christopher Hobbs, Roy Upton, Alicia Goldberg
• In the absence of information herbs are
categorized as “Class 1: herbs that can
be safely consumed when used
• Published in 1997
• Distinction between pregnancy &
lactation is made
• Very comprehensive in terms of number
of herbs listed
The Essential Guide to Herbal Safety
by Simon Mills & Kerry Bone
• Distinction between pregnancy &
lactation is made
• In depth information on each
herb with rationale and
• Pregnancy ratings: A, B1, B2,
B3, C, D, X
• Lactation ratings: ND, C, CC,
• Appendix includes herbs in list
Herbal Contraindications
and Drug Interactions
Plus herbal adjuncts with medicines, Fourth edition
By Francis Brinker, N.D.
• 4th edition, published 2010
• Easier format than previous editions
• More explanations, especially of
warnings based on in vitro evidence
• Extremely cautious ratings
• This source often contraindicates herbs with
pregnancy that other sources do not
• References are online, as well as
Botanical Medicine for Women’s Health
by Aviva Romm
• Best information regarding
clinical experience
• Comprehensive chart in back
with safety info
• Only a few full monographs,
so some hunting by subject is
required to find all the info on
individual herbs
• Published 2010
American Herbal Pharmacopoeia
by Roy Upton
• Extremely well-researched
• Publishing dates vary from 1997 to
• 29 monographs
• PDF = $39.95, Paper copy =
Herbs & Natural Supplements
An evidence-based guide
by Lesley Braun & Marc Cohen
• Safety ratings are middle of
the road
• Sometimes references
secondary literature, like
Mills & Bone, sometimes
actual studies
The ABC Clinical Guide to Herbs
by Mark Blumenthal
• Published 2003
• Only about 30 monographs
• Tends to reference
Commission E, Brinker,
AHPA for
pregnancy/lactation info
A Clinical Guide to Blending Liquid Herbs
By Kerry Bone
• Ratings are very succinct, explanations
are short
• In the absence of evidence, it rates
herbs as “no adverse effects expected”
• On the lenient-side
• Published prior (2003) to The Essential
Guide to Herbal Safety (2005)
Clinical Applications of Ayurvedic and
Chinese Herbs
by Kerry Bone
• Source for Ayurvedic and
Chinese herbs
• Does not specifically outline
pregnancy/lactation safety
• Published 1996
Native American Ethnobotany
by Daniel Moerman
• Primary source for Native
American use
• Can lead to source for “traditional
use” information
• Will not contain warnings based
on modern understanding
King’s American Dispensatory, 1898
by Harvey Wickes Felter & John Uri Lloyd
• Source for Eclectic
physician use
• Often the primary source of
“traditional use” information
• Clinical use is very
• $10/year subscription
• Online, so it is kept updated
• Everything is referenced / hyperlinked if
• Extremely cautious ratings
• Almost every herb says “insufficient reliable information,
avoid use”
• Almost every herb has a listing
• Well referenced with hyperlinks to articles
• Online, so it is kept up to date
• Often provides more information than Natural
Medicines Comprehensive Database, though
conclusions are also extremely cautious
• Expensive, this will limit access for most
P1 & L1 Ratings
• Even the safest of herbs all have at least 1
source that lists it as unsafe or unknown
• Herbs commonly accepted as safe during
pregnancy listed in Aviva Romm’s book:
Red raspberry
Lemon balm
• known safe, but commonly cited as contraindicated
during pregnancy
• 1979 study that found teratogenic effects using high doses
of a concentrated extract of alpha-bisabolol (oil constituent
found in chamomile)
• lower doses were not shown to be teratogenic
•It would not be possible to drink enough tea to approximate
the teratogenic dose of this constituent
Lemon balm
• Listed as safe by AHPA, Romm, and Bone
– Romm suggests it as a safe choice for insomnia during 3rd
trimester, but to avoid with thyroid conditions/medications
• But Brinker says to avoid during pregnancy
– Emmenagogue effects (empirical)
– Antithyrotropic (in vitro) and antigonadatropic (animal
• compatible with breasfeeding
• essential oil may pass into breast milk, producing a
mild sedative effect in the baby
Mills & Bone Category A herbs
No proven increase in the frequency of malformation or other
harmful effects on the foetus despite consumption by a large
number of women
Bilberry fruit
Raspberry leaf
*Safety issues exist (Romm)
• Large amounts (500mg glycyrrhizin or greater
per week)
– Associated with pre-term & early term delivery in humans
– 1049 Finnish pregnant women tracked their licorice candy
consumption and were grouped into 3 groups
• Low = less than 250mg glycyrrhizin per week
• Moderate = 250-499mg
• Heavy = more than 500mg
Am. J. Epidemiol. (2001) 153 (11): 1085-1088.
• Heavy consumption doubled the risk of giving birth
before 38 weeks
• No effect was seen on maternal blood pressure
– European authorities advise it is likely safe in
doses up to 3g/day (Mills & Bone, 2005)
Garlic and pregnancy
• A small clinical trial observed that garlic
ingestion by pregnant women significantly
alters the odor of their amniotic fluid
• Garlic has been noted on more than one
occasion on the breath of newborn Pakistani
• Precautions about dosage are cited by
multiple sources
– Large doses of fresh raw garlic or allicin-releasing
products should not be consumed during
pregnancy to avoid bleeding complications
Garlic anticoagulant concerns
• A single case report exists for an 87 year old
man who developed platelet dysfunction after
chronic consumption of 2g/day fresh cloves
• 5g/day fresh garlic is contraindicated with
– 2 cases of stabilized patients on warfarin whose
INR increased and clotting times doubled after
intake of garlic products (garlic oil and garlic
Garlic anticoagulant concerns
• several cases of bleeding
complications during surgery
associated with garlic intake
– A 2002 report of odorless garlic tablets taken
regularly, including 5 taken the day before surgery
(equivalent to 5g fresh bulb) resulted in
– 1995 “heavy garlic intake” before cosmetic surgery
resulted in bleeding complications and prolonged
bleeding time
Garlic and Lactation
• Used as a galactagogue in India
– Small placebo-controlled study showed:
• garlic ingestion significantly and consistently increased the
perceived intensity of the milk odor
• which peaked in strength 2 hours after ingestion
• babies detected theses changes, as indicated by:
– increased time of attachment
– more suckling
– tendency to ingest more milk
• a follow-up study showed that the novelty wore off as
infants got accustomed to the flavor and they returned to
their usual feeding patterns
Garlic and topical use
• Should not be used topically!
– Not safe for baby to be exposed to it
• Internal use by the mother in cases of
breast candidiasis may be useful
Fertility herbs
• Herbs used for fertility are not
necessarily safe to continue once
pregnancy has been achieved
• Traditionally used as an abortifacient
• If using to promote fertility, it should be
discontinued when pregnancy is
• Compatible with breastfeeding
• Used in Ayurveda to promote lactation
Chamaelirium (False Unicorn Root)
• Considered helpful in amenorrhea and difficulty
• Not a traditional use by Native Americans or Eclectics
– Eclectics used it for “uterine weakness in which relaxation
of the tissue is so great as to give the sensation of
downward pressure, dragging or expulsion…a sensation as
if everything from the pelvis would fall out or be expelled”
• Popularized as a fertility agent by modern herbalists
• Listed as abortifacient by AHPA
• No safety data exists for its use during pregnancy and
it has been shown to possess uterine stimulant
activity (empirical)
L1 - compatible with breastfeeding
Concerns during Pregnancy
• Ist trimester:
– Nausea/Vomiting
– Miscarriage prevention
– Urinary tract infections
• 2nd trimester:
– Heartburn / Reflux
– Iron deficiency anemia
3rd trimester concerns
Hypertension / Preeclampsia
Group B strep
Uterine irritability / Pre-term labor
Labor - delayed labor, rigid cervix, ineffective
contractions, fatigue, pain, anxiety
• Often used for amenorrhea and to
regulate irregular cycles
• Used to prevent miscarriages
• Ideally given for 3 months prior to conception
and continued past the date of previous
• Thought to be progesterogenic via its affects on
• Most popular self-medication among pregnant
• Generally recommended not to exceed 1g/day due to
emmenagogue concerns
• Multiple studies on ginger for nausea & vomiting
during pregnancy suggest up to 2g/day of dried root
is safe and effective
• AHPA lists fresh root as class 1, but dried root as
contraindicated during pregnancy
• It was contraindicated by Commission E based on in
vitro research on single compounds
– Of course leading to other sources to list as contraindicated
L1 - compatible with breastfeeding
Cramp bark / black haw
Long history of use by Western herbalists and Native Americans
as a spasmolytic for threatened miscarriage
Officially listed in the United States Pharmacopoeia in 1882
It’s use as an antispasmodic and preventative for miscarriage
was popularized by the Eclectic physicians
Small doses were considered excellent by the Eclectics to ease
irregular contractions and “greatly facilitate a speedy and
uncomplicated labor”
Still widely used by contemporary midwives and herbalists
during labor to arrest uterine spasm when there is uterine
cramping without cervical dilation and protracted early labor
Uva Ursi
• 2 decades of use among midwives for acute
cystitis during pregnancy has resulted in no
adverse reports
• Use during 1st trimester should be limited to 4
– Concern about potential to stimulate uterine
contractions cited by secondary sources
– This concern does not reflect actual reports or
clinical observance
– UTIs alone can cause uterine contractions
Uva Ursi and hydroquinone
• Uva ursi contains arbutin which is
metabolized into hydroquinone
• Hydroquinone has been shown to be toxic to
humans in large amounts (industrial handling
• It is used in black & white film development and
is a controversial ingredient in beauty products
as a skin lightener
Uva Ursi and hydroquinone
• These reports have led to theoretical
warnings that uva ursi is toxic in general, and
especially during pregnancy
– Hydroquinone has been shown to have mild
negative affects on reproduction in rats
Reduced maternal weight gain
decreased fetal weight
increased resorption
reduced male fertility
Uva Ursi and hydroquinone
• Concerns regarding fetal toxicity of
hydroquinone appear to be exaggerated
• At a maximum dose of 12g, at a minimum
expected concentration of artbutin of 12%, at
100% solubility and absorbability, the highest
potential hydroquinone concentration per full
daily dose would be 1440mg – well below the
established NOEL (no observed effect level)
of 5250mg of pure hydroquinone daily
• Upton, R. American Herbal Pharmacopoeia and
therapeutic compendium.
Uva Ursi and Dosage
• Case report of one woman who consumed
uva ursi regularly for 3 years who developed
bulls-eye maculopathy
• This was likely due to the inhibition of melanin
synthesis since arbutin is metabolized to
hydroquinone which is known to inhibit the
enzyme tyrosine kinase involved in
synthesizing melanin
Brinker, F. (2010). Herbal contraindications and drug
Uva ursi and Lactation
• No studies on Uva ursi in lactating women
• Hydroquinone was studied on lactating rats
and no toxicity was found
• Use during lactation is strongly discouraged
by Mills & Bone due to arbutin/hydroquinone
• Aviva Romm suggests use during lactation is
possible if a low dose is used and the infant is
closely monitored by a qualified health
Horse Chestnut - varicosities
• High doses given to rabbits decreased
fetal weight gain
• But clinical studies to treat venous
conditions in pregnant women at doses
of 600mg (containing 100mg aescin) for
2-4 weeks have been successful
L2 - compatible with breastfeeding, but use caution
Insomnia and pregnancy
• Chamomile - P1
• Lavender - P1
• Skullcap - P1
– Eclectic texts indicate that a concentrated
preparation of skullcap was combined with other
nervines and spasmolytics for various female
disorders in both pregnant and non-pregnant
– Source is important to avoid adulteration with
Insomnia and pregnancy
• Lemon balm - P2
• Valerian - P2
• no problems were noted in 3 cases of intentional
overdose with 2-5g of valerian during weeks 3-10 of
• valerian is one of the most commonly used herbs during
pregnancy and was not associated with any negative
– though it is not recommended due to theoretical concern
over teratogenic effects of valepotriates
– Valepotriates have been shown to be cytotoxic and
mutagenic in vitro
– however valepotriates degrade rapidly and are typically not
found in commercial preparations
• Passionflower - P2
Red Raspberry Leaf
One of the most historically venerated herbal uterine tonics
Recommended by herbalists/midwives as an infusion, 1-3 cups
Of all the herbs that might be considered for labor preparation,
red raspberry appears the safest
– Used to strengthen the uterus, improve labor outcome, prevent
excessive bleeding
– 1 study indicates 63% of US midwives use to stimulate labor
• though it does not appear very effective at stimulating labor
– 1 study showed a reduction in length of second stage labor and
reduction of delivery by forceps
– Another study showed a reduced rate of pre and post-term
gestation and reduced need for obstetric interventions including csection, forceps delivery, amniotomy, and vacuum extraction
Red Raspberry Leaf, minor cautions
Can cause nausea in 1st trimester due to astringency (Romm)
Best to restrict use to 2nd & 3rd trimesters (Braun, Bone)
Avoid in history of labor that comes on suddenly, hard, fast, and
strong due to uterine stimulant activity (in vitro) (Brinker)
1 case of a pregnant woman who discontinued use after
experiencing increased Braxton-Hicks contractions, however
causality was not confirmed (Mills & Bone)
– Suggested to slowly increase dose over a period of weeks to reduce
chance for Braxton-Hicks contractions (Denise Tiran, 2003)
Pharmacological experiments have yielded conflicting data on
uterine contraction and relaxation, but overall results imply a
regulatory action on contractions (Mills & Bone)
Black cohosh
• Avoid during 1st trimester (though potentially
useful for threatened miscarriage)
• Emmenagogue
• Used by Cherokee to stimulate menstruation
• Its influence on hormones is still not understood
• Reports of hepatotoxicity
• Historical use as a partus preparator
– This is what led to modern contraindications during pregnancy
Eclectic use during pregnancy
• Eclectics used for:
– Threatened miscarriage
– Premature labor
– Relaxation of the os uteri during labor
– Often in combination with Viburnum prunifolium
• Eclectics also used it:
– During labor when the pains are “inefficient, feeble, or
irregular to stimulate normal action” and it was deemed an
excellent partus preparator when given for several weeks
before birth
Kings, 1898
Used to reduce and promote
uterine contractions?
• Dosage
– Low doses were used for threatened miscarriage
– Higher doses were used to induce labor
• Current use in midwifery:
– assist labor in fairly low doses, often combined with other herbs
– prevent threatened miscarriage
Safety during Eclectic use
• Widespread use by Eclectics during pregnancy
• Thousands of case reports
• Very few adverse effects noted
– Cook reports in 1869 a rare case of threatened abortion
while it was being used during pregnancy
– In I919, Ellingwood reports 6 cases of severe uterine
hemorrhage following its use during labor
Safety recommendations today
• The prudent practitioner should avoid
the use of black cohosh during
• Except for use during labor to relieve
pain and spasmodic uterine
contractions associated with
dysfunctional labor
Aviva Romm. Botanical Medicine for Women’s Health, 2010.
Black Cohosh and Lactation
• Mills & Bone and Romm strongly discourage
its use while breastfeeding
• Lack of data
– Don’t know its affect on breastfeeding babies
– Or its effect on lactation
• Studies on its effect on estrogen are
• More recent studies suggest it has no estrogenic effect
Black Cohosh and Lactation
• Used by the Iriquois to “promote the flow of
milk in women” (Moerman, 2000)
• Does not seem to effect prolactin, but this has
not been studied in lactating women
• Not contraindicated during lactation by
German Commission E or AHPA
Blue Cohosh - history
• Historical use as a partus preparator and to induce
• Used to promote childbirth by the Cherokee and
• The only specific information on how it was used by
Native Americans was offered by the “Indian Doctor”
Peter Smith in 1813:
• He claimed it was used for 2-3 weeks prior to delivery as
well as during labor
• This use was popularized by the Eclectics who added
specific indications
• It was used “to relieve false labor pains and thought to be
most valuable to coordinate and strengthen contractions
in prolonged labor due to debility and fatigue where the
tissues feel full, as if congested”
Blue Cohosh - history continues
• Late 1800s / early 1900s
• Added to United States Dispensatory
• Added to United States Pharmacopoeia
• Early 1900s
• Use declines as herbs fall out of favor
• 1978
• Its use as an emmenagogue & uterine tonic are
popularized by Jeannine Parvati-Baker in Hygieia
• 1986
• Use during childbirth is promoted by Susun Weed in
Wise Woman Herbal The Childbearing Year
• 1990s
• Blue cohosh is among the most widely used herbs for
assistance in labor
Blue Cohosh - safety concerns arise
• 1996-1998
• 3 case reports appear in the literature
suggesting severe adverse neonatal outcomes
associated with maternal ingestion of blue
cohosh including:
focal motor seizure
myocardial infarction
ischemic stroke
multi-organ hypoxic injury
permanent central nervous system damage
profound congestive heart failure
Blue Cohosh
Gunn and Wright Case Report, 1996
– Combination of Blue and Black Cohosh administered to a
41.6 weeks pregnant woman to attempt labor induction
– Baby girl was born unable to breath spontaneously
– Midwives proceeded to deliver CPR for 30 minutes
– Baby gasped and was transferred to hospital where she
required mechanical ventilation
– Infant had seizures and was diagnosed with kidney and brain
– Authors of the case report suggest the hypoxic-ischemic
damage was due to myocardial toxicity secondary to blue
– Though they do question if inadequate resuscitation was a
possible factor
Blue Cohosh
Jones and Lawson Case Report,1998
– 36 yr. old mother of 3 children gave birth to
a boy at 41 weeks
– She took 1 blue cohosh tablet (otherwise
unspecified) 3x/day for 3 weeks prior to
– During that time she noticed:
• increased uterine activity
• decreased fetal movement
Blue Cohosh
Jones and Lawson Case Report,1998
• 20 minutes after delivery baby developed respiratory
distress, acidosis, ischemic hepatitis, and shock
• He was intubated, given mechanical ventilation and
moved to neonatal intensive care
• He was diagnosed with enlarged heart and with
having had a myocardial infarction
• No signs of infection or congenital cardiac anomoly
existed to explain the condition
• At 2 yrs. old the child remained on digoxin therapy
Jones and Lawson - Case Discussion
• The authors concluded that presentation of
cardiogenic shock and MI were consistent
with the known pharmacology of blue cohosh
• Although causality cannot be definitively
established, it demonstrates the most
plausible case for relationship between blue
cohosh use and a neonatal ischemic event
– Case is comprehensive, generally allowing other
causes to be excluded
– Although blue cohosh product was not
authenticated, dose, duration of use, and form are
Jones and Lawson - dosage issues
• The crude herb as would be found in capsule
or tablet contains more saponins than would
be found in a tincture
– Saponins have been associated with uterine
stimulant activity
– Thought to be responsible for cardiotoxic effects
on newborns
• 3x the suggested dose on the label was used
Jones and Lawson - conclusions
• Decreased fetal movement could have been
a signal of placental insufficiency
• Fetal complications begin to increase after 41
weeks gestation
• Cardiomegaly could have been due to either
the blue cohosh, placental insufficiency, or a
combination of the two
Blue Cohosh - research
• Research into mechanisms of action
– embryotoxic and teratogenic alkaloids
• anagyrine and baptifoline
– Saponins are thought to be responsible for
uterine stimulation
Blue Cohosh - current recommendations
• Consensus to discontinue its use during
all phases of pregnancy
– If it is to be used during labor:
• Only the tincture should be used
• Only under supervision of qualified maternity
health professional
• Proper fetal and neonatal monitoring (not for
use in homebirth)
Should herbs be used during lactation?
What are the potential benefits?
• Enhanced milk production
• Galactagogues have a long history of traditional use
• In the Netherlands, anise seed cookies are a traditional
gift given to new mothers
• 85% of Indian mothers who are breastfeeding will
consume large amounts of fenugreek in the form of a
traditional food called methipak to act as a galactagogue
and general strengthening tonic
• Address health concerns of the mother while
avoiding pharmaceuticals
• Is the mother being told to wean so that she can take a
Should herbs be used during lactation?
What are the concerns?
• Adverse effect on infant
– What are the potential effects of the herb being
How old is the baby?
Is the baby exclusively breastfeeding?
Is the baby eating other foods?
Is it a toddler with minimal nursing habits?
• Adverse effect on lactation
• Galactagogues are not always desirable
• Will the herb dry up milk supply?
• Is it for external use on the breast?
• Potential for baby to ingest directly
Do phytochemicals enter the milk?
• Foods in the mother’s diet can
obviously affect the baby
– Cruciferous vegetables
• Cause crying & colic
– Coffee & Chocolate
• Act as stimulants
Lactation Considerations
• Bioavailablity
– Must be absorbed into bloodstream to get
into breast milk
– If in the bloodstream, usually only 1% will
enter breast milk
– Some exceptions can enter breast milk up
to 10%
– Less than 10% is usually too small to have
a pharmacological effect
Iodine & Alkaloids
• Most chemicals do not get sequestered in
breast milk, with a few exceptions:
– Iodine is actively transported into breast milk
• Too much potassium iodide can cause hypothyroidsm in
• If there is contamination with radioactive iodine 131,
potassium iodide should be taken by a breastfeeding
mother at a dose of 130mg/day if recommended by
government agencies
• Same as above for pregnant women (Thomas Hale Ph.D)
– Alkaloids (weakly basic) concentrate in (slightly
acidic) breast milk
Protein binding
• Substances bound to proteins are not
free to diffuse into breast milk
– Ex. Coumadin is 99% bound to serum
– Miniscule amount gets into breast milk
– No consequence to infant
Size of molecules
• Large molecules do not enter breast milk
– Insulin
– Heparin (injectable anticoagulant)
• Very small molecules enter breast milk
– Ethanol
– Volatile oils
Lipid solubility
• Lipid soluble chemicals enter breast
milk more easily
– Higher than expected levels can occur
– Ex: fluoxetine (prozac)
• One study found larger concentrations of
fluoxetine in post-feeding breast milk than prefeeding breast milk
• Lipid concentration of breast milk increases
during feeding
First days of nursing
• Enhanced bioavailability of chemicals during
colostrum production
• Junctures between cells allow
immunoglobulins in the bloodstream (as well
as other chemicals) entry into colostrum
during first 3-10 days of breastfeeding
Age & weight of infant affect
elimination capacity
• Newborn
– Immature gut, liver, kidney function
• 2 weeks
– Liver more developed, jaundice disappears
• 4-5 months
– Kidney clearance capacity fully developed
Studies on lactation & pharmaceuticals
• The amount of drug entry into the milk is usually only
studied during one stage of feeding
• Few drugs have been studied over the long term
of weeks or months of exposure
• Despite this lack of information, there are very few
reported adverse reactions
– while there are increasing numbers of mothers taking
pharmaceuticals while breastfeeding
• Predictions are made based on how drugs are
metabolized by the mother
Studies on lactation and
herbal medicines
• Assessment is hindered by lack of
information about
– Bioavailability
– Serum levels
– Half life
– Protein binding
Lactation and herb risk
• Despite a lack of information
– Very few cases of adverse reactions are
documented involving ingestion of
phytochemicals via breastfeeding
– 1 case of infant death
• Mother used both coltsfoot and petasites both
during pregnancy and while breastfeeding
• Both contain toxic pyrrolizidine alkaloids
• PAs cause irreversible liver damage
• Galactagogues stimulate the production
or flow of breast milk
• They may act hormonally
• They may act as nutritives to improve
milk quality and quantity
• Nervines are often combined to
encourage relaxation and promote milk
let down
Herbal Galactagogues
Marshmallow root
Blessed thistle
Fennel seed
Goat’s Rue
Anise seed (not to be confused with
Chaste Tree Berry
Star Anise which is associated with
to promote milk let-down
Blue Vervain
Aviva Romm. Botanical Medicine for
Women’s Health, 2010.
Lactation & Prolactin
• Initial production of milk is driven by high serum
prolactin levels in the mother
• Prolactin levels rise in response to each feeding
• Later, each breast independently produces milk in
response to milk removal
• Prolactin levels are near normal between nursing
sessions with spikes after each feeding
• Frequent & high prolactin spikes are associated with
– Good milk supply
– Maintenance of lactation amenorrhea
• Traditional use as a galactagogue
• Can create a maple syrup-like smell to baby’s urine,
but should not be confused with maple syrup urine
• No controlled studies
• 10g/day significantly increased milk yields in goats
• In India a traditional food called methipak, made of
wheat, fat, sugar, and generous amounts of
fenugreek, is used by 85% of lactating mothers (1985
• Said to act as a galactagogue, strengthener, and reducer
of body aches
• Used during last 1-2 months of pregnancy
• And from 10 days post-partum for 1-2 months
• Common to consume of 50g methipak in the morning
Chaste Tree Berry & Lactation
• Only herb with studies on human
– 2 clinical trials done in the 1950s showed
that chaste tree increased milk supply of
nursing mothers
– Despite methodological flaws, the findings
consistently showed a galactagogue effect
of the herb
Vitex and Prolactin
• in vitro evidence and 1 rat study show
prolactin-inhibition, suggesting that chaste
tree inhibits lactation
• one reason it is listed by some sources as
contraindicated during lactation
• This information directly opposes its use as a
galactagogue (and historical use by monks to
reduce libido)
• Differences in results could be due to:
dosage used
differences between human and rat physiology
character of the extract administered
route of administration (oral vs. injected)
Vitex may have a dose-dependent
effect on prolactin
• Males were given differing doses of chaste tree:
120mg, 240mg, 480mg, & placebo
• The lowest dose of 120mg showed a stimulating
effect on prolactin levels
• The middle dose of 240mg showed no effect
• The highest dose of 480mg showed an inhibitory
Why would this be?
• Need to understand the relationship between
dopamine and prolactin
• Dopamine is both a neurohormone and
• When dopamine is released from the
hypothalamus, it acts like a hormone and has
an inhibitory effect on prolactin release from
the pituitary
Dopamine secreted by the hypothalamus
inhibits prolactin release from the pituitary
Dopamine = prolactin-inhibiting factor
Anterior Pituitary
Decreased Prolactin release
Vitex has been shown to be
• Vitex has affinity for dopamine D2 receptors
in vitro
• Diterpenes have been implicated as active constituents
interacting with dopamine receptors
• Dopaminergic activity decreases prolactin
• This is why vitex is thought to be useful in:
• Hyperprolactinemia
• Corpus luteal deficiency, which can lead to progesterone
• Amenorrhea
• Premenstrual mastalgia
Low dose Vitex
Higher dose Vitex
Dopamine Inhibition
Dopamine Stimulation
Anterior Pituitary
Increased Prolactin
Decreased Prolactin
How does Vitex affect progesterone?
• Rat studies have shown that prolactin
increases progesterone by maintaining the
structure of the corpus luteum after mating,
thereby increasing progesterone release
(Freeman et al, 2000)
• Logically, in order for chaste tree to increase
progesterone, it would have to increase
– The only way it could do that is if it was inhibiting
dopamine, not stimulating it
Topical use of herbs during lactation
• Herbs used on the body, but not on the breast, are
generally considered safe while breastfeeding
• Herbs used on the breast must be safe and non-toxic
to the baby
• Baby should be nursed prior to application of
anything to the nipple and nipples should be rinsed
before feeding
– Do not want baby to develop aversion to the breast due to
bitter taste
Concerns about topical application to breasts
• The skin of the areola is very thin compared
to other skin on the body
– Very sensitive
• higher chance of allergic reaction
– Substances more easily absorbed through it and
into the breast
– Wiping away potentially toxic herbs before nursing
may not be enough
– It is possible that substances applied to the breast
will be absorbed into the breast tissue and enter
milk ducts in relatively large amounts
• Comfrey should be avoided due to PAs
• Essential oils should be avoided, including tea tree oil, which
has had 2 cases of known toxicity via oral ingestion
St. John’s Wort & pregnancy
• Strong evidence that SSRIs taken during pregnancy
cause neonates to suffer withdrawal symptoms
• St. John’s Wort is not contraindicated during pregnancy, but
safety studies are lacking
• Used by the Cherokee with other herbs to promote
menstruation (Moerman, 2000)
• High doses show reduced litter sizes and smaller offspring in
• Case report of a 38 yr. old pregnant woman taking 900mg SJW
6:1 extract from 24 weeks until 24 hours prior to delivery
• resulted in a healthy baby
• mother discontinued SJW postpartum and initiated
• the neonate developed jaundice on day 5, mother resumed
SJW on day 20 (300mg) and continued breastfeeding
• behavioral assessment at 4 and 33 days was normal
SJW & pregnancy
• 2009 prospective cohort study conducted by
Motherisk, Hospital for Sick Children,
Toronto, Canada
54 pregnant women exposed to SJW
54 pregnant women on antidepressant meds
54 pregnant women with no teratogenic exposure
Results showed no major malformations across
the 3 groups (5%, 4%, 0%)
• (major malformation rate across general population is 35%)
Jean-Jacques Dugoua, 2010
St. John’s Wort and lactation
• 300-480mg SJW/day has shown low levels of
hyperforin excreted into breast milk
• No side effects seen in infants
• The plasma of one infant whose mother was taking
300mg/day showed no detectable constituents
• Thomas Hale, lactation & medication expert,
suggests that the transfer to milk of SJW is minimal
and it appears safe during lactation
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