- [Voiceover] Postpartum hemorrhage,
it's as scary as the name sounds,
and it is always an emergency.
Unfortunately, it's not an uncommon one
because postpartum hemorrhage is one
of the top three causes of maternal mortality,
and it is the absolute most common reason
that postpartum women are admitted to ICUs,
or Intensive Care Units.
You guys probably want a definition
of postpartum hemorrhage.
I wish I could give you a simple, clear cut definition,
but people have been struggling
with coming up with one for a really long time.
There's what I think is the best definition,
that postpartum hemorrhage is any significant
amount of blood loss that occurs after delivery
that makes the woman symptomatic.
So an amount of blood loss
that makes the woman feel fatigued,
or light-headed, or confused and sweaty,
or perhaps makes her look pale,
or a significant amount of blood loss
that results in signs of low blood volumes.
So signs such as low blood pressure,
or rapid heart rate,
or perhaps decreased urine production.
So that's what I think is the best
sort of definition of postpartum hemorrhage,
any significant amount of blood loss
that either results in symptoms
or in signs of low blood volume.
Then there's the most common definition,
that postpartum hemorrhage is a blood loss
of more than 500 milliliters,
so more than 500 milliliters,
after a vaginal delivery,
500 milliliters after a vaginal delivery,
and more than 1,000 milliliters
with a C section.
But this isn't the best way really
to define things since practitioners
tend to underestimate the amount of blood loss.
Actual studies have shown that.
Then finally, there's a definition
that postpartum hemorrhage is anything
that results in more than a 10% fall
in hemoglobin concentration.
Hemoglobin is a lab measure of the amount
of red blood cells that you have in the body.
This definition is even more problematic
because it takes time for the blood loss
to be reflected in lab values,
and that time could delay treatment.
All right, so hopefully that convinces you
that this whole area of defining
what postpartum hemorrhage is
needs some work.
Well let's step away from that
and let's talk about what
causes postpartum hemorrhage.
So first, remember that after the delivery
of the baby, the placenta separates
from the uterus.
That leaves these vessels that supplied
the placenta broken and ruptured,
but the myometrium, so the muscular layer
of the uterine wall, contracts and constricts
these blood vessels to stop the bleeding.
The reason why that works is because
of the way that the muscle fibers
of the uterus are arranged in kind
of a crisscross pattern around the blood vessels.
So if these are the muscle fibers of the uterus there,
they're arranged as kind of a lattice
around the blood vessels
so that when the muscle fibers contract,
they actually clamp down on the blood vessel
to stop the bleeding.
After that happens, the coagulation pathways
activate and they form a clot
at the site at which the placenta
was initially attached.
Okay, so if you understand all of that, hopefully,
you'll understand that any disturbance
in any one of those events
will lead to a postpartum hemorrhage,
or an excessive bleeding after the delivery
of the baby.
So for example, you could have a problem
with the uterus not contracting well enough,
which is called uterine atony.
So uterine atony, where the a stands
for lack of.
So lack of tone in the uterus.
And you'll actually feel a floppy,
sort of limp uterus in that case.
There are a few different things
that can cause uterine atony to occur.
So if the uterus is over-distended for some reason,
either from having multiple fetuses inside it,
so if a woman is having twins,
or triplets, or quadruplets,
or if the uterus has one baby,
but that one baby is larger than normal,
or perhaps if there's too much amniotic fluid
inside the uterus, so any cause of over-distension
of the uterus can lead to atony.
Or the atony could result
from using uterine relaxing agents,
or even from uterine fatigue from having
really prolonged labor.
So atony is one cause of postpartum hemorrhage,
and actually it's the most common cause
of postpartum hemorrhage.
Now if you feel the uterus and the uterus feels
really firm and well contracted,
then we have to consider another cause.
So what are some of the other causes
of postpartum hemorrhage?
Well postpartum hemorrhage could also be
the result of a coagulopathy.
So it could be the result of a coagulopathy,
which is a term that we use to describe
any sort of problem with the clotting cascade.
And you can have problems
with the clotting cascade as a result
of acquired or even inherited
clotting factor deficiencies.
So you could have too few clotting factors
circulating in the blood.
There are even certain drugs that can affect
coagulation, that can impair coagulation.
Now if none of those causes are present,
so if there's no uterine atony
and there's no coagulopathy,
it's really important to consider trauma,
or perhaps even lacerations that occurred
during the delivery.
So you need to do a vaginal exam at that point
to see if any of those causes are present.
Now as far as treatment goes,
postpartum hemorrhage isn't treated
much differently from other causes of hemorrhage.
If uterine atony is the cause of the hemorrhage,
we usually try first a uterine massage,
and we'll usually add on a uterotonic agent,
so an agent that helps the uterus contract,
to help the myometrium contract,
and clamp down, and stop the bleeding.
If coagulation defects are to blame,
that's treated with usually a transfusion
of blood products containing the factors
that are deficient in the patient's blood.
Traumatic bleeding lesions
are usually treated surgically.
But again, with all of these different causes,
you can't forget how you first and foremost
treat a hemorrhage, and that is
with repletion of blood volume.
So that's always very important.
All right, so that is postpartum hemorrhage
in a nutshell.