TRAINING and EDUCATION
Patient Education
• progestin-only pills, which studies show do not
increase the risk for blood clots
• age >60 years
The National Blood Clot Alliance
(NBCA) is dedicated to advancing
the prevention, early diagnosis,
and successful treatment of lifethreatening blood clots, such as
DVT, PE, and clot-provoked stroke.
NBCA works on behalf of those
who may be susceptible to blood
clots, including those with clotting
disorders, atrial fibrillation, cancer,
traumatic injury, risks related to
surgery, lengthy immobility, child
birth, and birth control.
Women should talk with their doctors about blood
clotting risks both before and while taking an estrogenbased birth control method.
Women should also be familiar with their family
history of blood clots. The most common inherited
disorder leading to blood clots is factor V Leiden, which
is typically suspected in individuals who develop blood
clots at a young age, who are white with European
ancestry, have a family history of clots, or have blood
clots in unusual sites.
For more information on NBCA,
visit stoptheclot.org.
Pregnancy and Child Birth
For more patient resources on
blood clots, visit stoptheclot.org/
learn_more/about-clots.htm.
For more information specifically
on a woman’s risk for blood clots,
visit womenandbloodclots.org.
• tubal ligation or vasectomy for their partner
Though pregnancy does not directly cause blood
clots, it does introduce a four-fold increased risk of
developing a blood clot. That risk increases to about
20-fold in the weeks immediately following childbirth,
and is at its highest – 100-fold – in the first week after
the baby is born.
Risk factors for blood clots related to pregnancy
and childbirth include hospitalization, surgery, trauma,
obesity, smoking, and immobility.
In general, there are three groups of women
who are advised to take blood-thinning medication
(anticoagulation) during pregnancy:
• women who have had a blood clot in the past and
are already on blood-thinning medication
• women who have had a blood clot in the past, but
are not currently on blood-thinning medication
• women who develop a blood clot during pregnancy
After labor and delivery, women who have not had a
blood clot but who have major risk factors also may
need anticoagulation for a short period of time. Major
risk factors include:
Though oral anticoagulants (such as warfarin, dabigatran,
rivaroxaban, and api xaban) are the most commonly
prescribed blood thinners, they are not considered safe
for the fetus. Women who take blood thinners should
contact their doctors immediately upon finding out they
are pregnant. The doctor may recommend switching
from oral anticoagulants to blood thinning medications
that are injected under the skin (subcutaneous
administration), such as standard or unfractionated
heparin and low-molecular-weight heparin (LMWH).
These medications do not cross the placenta or enter
the bloodstream of the fetus.
Childbirth While Taking Blood Thinners
Women are at a higher risk for a blood clot in the
six weeks following the baby’s birth, but it may be
necessary to suspend anticoagulation therapy to
minimize postpartum bleeding complications. After
delivery, women with clotting disorders should resume
anticoagulation therapy (no sooner than 4-6 hours after
vaginal delivery or 6-12 hours after Cesarean delivery)
and continue taking anticoagulants – either injections
or an oral anticoagulant – for at least six weeks postdelivery as the risk for bleeding is reduced. The duration
of anticoagulation after this point should be determined
by the individual woman’s risk. Women can breastfeed
while receiving LMWH injections or warfarin, but the
safety of newer oral anticoagulants (including dabigatran,
apixaban, and rivaroxaban) during breastfeeding has not
yet been established.
Women should discuss their potential risk factors
with their doctors, and make sure that they take steps to
address any risks, including:
• taking any prescribed medications as directed
• avoiding sitting still for prolonged periods of time
• making lifestyle changes, like losing weight and
quitting smoking
• prolonged immobilization, such as bed rest
• exercising regularly
• cancer
ASH Clinical News
Anticoagulation Therapy During Pregnancy
• an inherited blood clotting disorder
• smoking
88
• heart failure
Treatment of Menopausal Symptoms
As women approach menopause, they begin to
experience menopausal symptoms that are sometimes
treated with a hormone therapy, which contains
estrogen and can increase the risk of blood clots up
to three-fold. Again, the absolute risk of blood clots
associated with hormone therapy is 1 in 300 per year.
For women looking to avoid the risk of blood clots
related to hormone therapy, the physical effects of
menopause – such as mood changes, hot flashes,
sleeplessness, and vaginal dryness – can be managed
with non-estrogen-containing medications for
symptomatic relief.
When entering menopause, women with a history
of blood clots should only use hormone therapies
containing estrogen or progestin if they also are taking
anticoagulation. Women should talk with their doctor
about starting hormone therapy and the risks involved. ●
December 2016
Cut out and give to a patient
The National Blood Clot
Alliance Resources