postpartum bleeding: how much is too much?

04 Aug 2011 1 Comment

by Karen in Uncategorized Tags: hemorrhage, lochia, postpartum

I was recently discussing with a fellow midwifery student how difficult it is to estimate postpartum blood loss.  During pregnancy, blood volume expands by as much as 50% to allow for circulation of blood to the expanded uterus and placenta, and to provide a buffer for blood loss during the birth.  Some of this blood is lost during the birth, and the rest is expelled (along with tissue from the contracting uterus) in the form of lochia.

Although some blood loss is normal, postpartum hemorrhage is life-threatening and, in one midwife’s words, when a mama begins to hemorrhage, “We don’t play around.”

So how do you know the difference between normal blood loss and hemorrhage?  The traditional definition of hemorrhage is >500 mL between the birth of the baby and the delivery of the placenta, or >500 mL after the birth of the placenta but within the 24 hours after the baby’s birth. (Davis, Heart and Hands, 4th ed.)   (Note: I am assuming normal, physiological vaginal birth.  With a cesarean birth, the term “normal” is anything up to 1000 mL.)  You can rely on rules of thumb such as “saturating a pad in less than an hour”, but in many situations that can be hard to estimate. We need to keep an eye on our mamas as best we can, and the only way to master a skill is to practice. So we got some chux pads and a bathtub, and made up some fake blood, and started playing “bloody hemorrhagic mess”. Here are the results of our little experiment:

warning: images of fake blood following.  If you are sensitive to the sight of blood and simulated medical waste, or if these images might be triggering to you, please skip the rest of this post.

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1 cup, or approximately 250 mL, on our chux

after adding a second cup - also, doesn't this resemble the United States?

this is the amount most texts define as hemorrhage.  We noticed that at this point, it definitely puddled on the surface, and took way longer to soak in.  Also, the chux was heavy.  We each held it up for a few minutes to get an idea of how heavy that much blood would be.

after adding a third cup, for a total of 750 mL on the pad

after it had soaked in for a few minutes

We agreed that 3 cups, or 750 mL, is probably the maximum that a chux can soak up.  It was pooling on the top, spreading to the edges, and in fact, ran off two edges within minutes.  This is definitely past the point where I would already be halfway through emergency procedures to get the hemorrhage under control.

So, we now have a good idea of what is and is not normal for blood flow immediately postpartum at a vaginal birth.

Then we wanted to be able to estimate blood flow on a maxi pad, to help us help mamas figure out normal lochia flow.

1/8 cup, or maybe 30 mL, on a maxi pad

1/4 cup, or maybe 60-70 mL on a maxi

We both agreed that this is past the point we personally would allow our own pad to be soaked.  1/4 cup, or 1/8 of the threshold for hemorrhage, more than saturated the center of the pad and ran over the sides.  In fact, I myself would have changed at the 1/8 cup mark or before – at least on every trip to the bathroom if not when the pad started feeling wet.  So assuming most mamas are the same, I would guesstimate that a loose definition of too much would be oversaturating a pad in under an hour, which holds with what I was taught.

the back of the saturated pad

with just over 1/2 cup

the remains of the 250 mL we had planned to pour on the maxi

From here, we wanted to explore blood flow in the bathtub, as with a waterbirth.

immediately after adding 1 cup to our bathtub full of water

Notice that the water is still basically transparent.

after adding almost another cup

One thing I noticed is that my fake blood solution was much less… bloody in water.    My personal experience with waterbirth is that blood tends to keep its gooey, coagulating state in water, tingeing it much more darkly than this simulation.  So I would say our experiment was less valid here.. but, oh well.  Pressing on:

with 4 cups, or twice the threshold for hemorrhage

Again, with real blood, I believe the water would have been much more opaque.  Even so, it became hard to see the drain or a hand placed in the water.

From here, we wanted to test what we had learned.  Each of us left the room and returned to an unknown volume that we had to estimate.  Success!  We both estimated with a 100% success rate and good confidence in our estimates.

Side-by-side comparison of 3 cups (750 mL) vs 1 1/2 cups (375 mL)

See how the 3-cup amount (on the left) is spilling over the sides?  And the 1 1/2 cup is soaking in, with less puddling?  In a real setting, there would be amniotic fluid mixed in and making the volume appear greater, but generally you use the heavily-colored stain in the center and ignore the watery stuff along the sides.

All in all, our experiment was a tremendous success and I feel much more confident in the skill of assessing postpartum bleeding.