Academic OB/GYN

In this month’s Green Journal, ACOG published Practice Bulletin #111 “Inherited Thrombophilias in Pregnancy”.  This practice bulletin was an attempt to coalesce the available evidence on thrombophilias in pregnancy and to make some evidence based recommendations for how obstetricians should deal with the issue.

This is all well and good, but what happened next was not.  A few weeks after publication ACOG retracted the Practice Bulletin.  Though we don’t know for sure, this was likely due to an outcry the many MFMs who don’t agree with the published recommendations.  As of now, it is no longer available online, and exists only in the pages of the printed journal.  Per ACOG, a new version will be out this summer.

So why did this happen?

Basically, it was because ACOG gutted any future for thrombophilia research with the following two recommendations (both of which were based only on level II evidence)

“Inherited thrombophilia testing in women who have experienced recurrent fetal loss or placental abruption is not recommended because it is unclear whether anticoagulation reduces recurrence.”

and

“There is insufficient evidence to recommend screening or treatment for thrombophilias in women with previous IUGR or preeclampsia.”

So are these recommendations wrong?  Its arguable.

The first statement that thrombophilia screening isn’t justified in cases of idiopathic abruption certainly seems to be a little suspect, given the multiple papers that have suggested an association between Factor V Leiden and abruption.   True, we do not know if treatment will reduce this risk, but is that a reason not to screen at all?  Would finding out a woman has a thrombophilia not affect her future care, whether it be by choosing not to use birth control pills, or to use some prophylactic anticoagulant around the time of a future leg injury or surgery?

The second statement is also a bit problematic.   It is fair to say that there is insufficient evidence to recommend treatment for thrombophilias in women with previous IUGR or pre-eclampsia, but to say that we should not screen in this population seems a little premature.   I wonder this statement was made based on a logical misinterpretation of recent data.

A recent study by Said et al demonstrated that in a low risk population screened for thrombophilias, one could not identify a connection between any of the thromophilias and IUGR or pre-eclampsia.  Based on this study, one might say reasonably that it is not worth it to screen for thrombophilias in a low risk population, as finding them will not predict bad outcomes.   But is this the same as what ACOG’s statement is forbidding?  I would say not.  ACOG is saying not only that we shouldn’t screen in low risk populations, but that also we shouldn’t screen in women of already demonstrated risk.  This is not fair, or at least not evidence based.  At this point, we don’t know if thrombophilas detected in women of already elevated risk are clinically meaningful. We know that in low risk people they don’t have a great effect, but this certainly doesn’t mean that they have no meaning in other women.  There are many risk factors for coronary artery disease that have greater meaning in constellation with other factors than they do alone.  It is too much to believe a similar situation could be at play here?   As such, there is very little reason for ACOG to “recommend” anything at all.  The right answer was “there can be no recommendation as we don’t really know.”

So why is this so important, and why did it get retracted?  A lot of it has to do with how insurance companies work, and how this statement would affect reimbursement for testing, and in turn future research.

As most of my readers know, insurance companies make money by collecting more in premiums than they pay out (and by earning money on the float.)  The best way to maintain this delta is to pay out as little as possible.   Now thrombophilia testing is rather expensive, so if they can find some way to not pay for it they will.   In fact, they would just love to have a document they could point to and say “See! There is no reason to do this testing.”  And this is exactly what ACOG handed them.

Insurance companies deny claims by claiming either that the test or treatment is not medically necessary, or that it is experimental/investigational.  By making the statement they did, ACOG made it very easy for any appeal reviewer to come down on the side of the insurer, and not cover testing.

So is this is a problem?  I think so, and I think a lot of other people thought so too, leading to enough groundswell to make ACOG retract the statement.

Thrombophilias are still are area of active research.  To say that we shouldn’t do testing in these situations is premature.  It would be fair to say that we don’t know if it is helpful, but to recommend against it is a statement “unencumbered by evidence.”

Future research in thrombophilias requires that we have a population of women who are known to be positive for some of these mutations.  This will only be available if we continue to do at least some testing in women who have demonstrated risk factors for having these mutations.    Will this testing help these specific women?  The only right answer is that we don’t know.   What we do know, however, is that if we completely stop running these tests research will grind to a halt, and we may never figure this thing out.

Now there are folks that completely disagree, hence the original practice bulletin.  Its not like it was a typo; it was indeed the opinion of a group of well educated people.  Perhaps thrombophilia testing is a waste of money.  Maybe there is some magic line of cost/benefit that this testing falls under.

But because so many disagree with these statements, I’m glad that ACOG pulled it back.  It will be interesting to see what replaces it, and whether it will leave room for testing in women of particularly high risk.

Inherited thrombophilia polymorphisms and pregnancy outcomes in nulliparous women.  Said JM, Higgins JR, Moses EK, Walker SP, Borg AJ, Monagle PT, Brennecke SP.  Obstet Gynecol. 2010 Jan;115(1):5-13.

ACOG Practice Bulletin No. 111: Inherited thrombophilias in pregnancy.  Obstet Gynecol. 2010 Apr;115(4):877-87.   American College of Obstetricians and Gynecologists Committee on Practice Bulletins-Obstetrics.