Drawing First Blood
We invite two experts to debate controversial
topics in hematology and health care.
Anticoagulation During Pregnancy
Jean Marie Connors, MD
Martina Murphy, MD
Disclaimer:
The following positions were assigned
to the participants and do not
necessarily reflect ASH opinions, the
participants’ opinions, or what they
do in daily practice.
Agree? Disagree? We want to hear
from you! Send your thoughts and
opinions on this controversial
issue to ashclinicalnews@
hematology.org.
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ASH Clinical News
Because of physiologic changes
during pregnancy, the risk of
venous thromboembolism
(VTE) is approximately five to
10 times higher than during
non-pregnancy, and the post-
partum risk is 15 to 20 times
higher. Safely and effectively
balancing the risks and benefits
of anticoagulation in pregnant
women is challenging, both be-
cause of the dosing complexi-
ties of the various agents in
this population and the limited
data available to guide treat-
ment decisions.
ASH Clinical News invited
Jean Marie Connors, MD,
and Martina Murphy, MD, to
debate the question: “What
is the appropriate type and
duration of anticoagulation
for women during pregnancy?”
Drs. Connors and Murphy
discuss the difficulties of
appropriate agent and dose
selection and the importance
of multidisciplinary care
in this setting. Dr. Connors
is medical director of the
Anticoagulation Management
Service at Brigham and
Women’s Hospital and Dana-
Farber Cancer Institute and
associate professor of medicine
at Harvard Medical School in
Boston, Massachusetts. Dr.
Murphy is assistant professor
of medicine and assistant
director of the Hematology/
Oncology Fellowship program at
the University of Florida College
of Medicine in Gainesville, and
co-director of the UF Obstetric
Hematology Clinic.
Jean Marie Connors, MD: The incidence
of VTE during pregnancy is approxi-
mately one to three per 1,000 deliveries. 1
The risk is increased because, during
pregnancy, the balance is incredibly
tipped toward a procoagulant state –
both because of increased levels of natu-
ral procoagulants and decreased levels of
natural anticoagulants.
Martina Murphy, MD: Absolutely, there
are aspects of both pregnancy and the
postpartum period that make women
hypercoagulable.
During pregnancy, women experience
progesterone-induced venodilation,
which promotes venous stasis, venous
compression by the uterus, and
compression of the left iliac vein by the
right iliac artery. In addition, pregnancy
causes changes in the hemostatic system
that create a hypercoagulable state; this
includes decreased protein S activity,
increased protein C resistance, and other
factors that lead to increased thrombin
production (higher levels of factor VIII,
factor IX, and fibrinogen, for instance).
Postpartum, we have to think about
the vascular damage to the vessels during
delivery, and that women are usually
immobilized for some period of time
after delivery. These factors make for the
perfect storm of hypercoagulability.
For me, decisions about
anticoagulation in pregnant women
must marry risks and benefits to both
mother and baby, which may not
always align. The phase of p regnancy
is also an important consideration: We
approach anticoagulation differently
in the antepartum period than we do
as delivery nears, when a woman may
desire neuraxial anesthesia or require a
surgical approach to her delivery.
In the postpartum period, we need
to know whether a woman taking
anticoagulants intends to breastfeed, as
certain anticoagulants can be detected
December 2017