Jump to content

JOIN THE DISCUSSION!

Want to join the discussions?

Sign up for a free membership! 

If you are a member already, log in!

(lost your password? reset it here)

99nicu.org 99nicu.org
  • entries
    173
  • comments
    139
  • views
    90,361

Antenatal steroids may well benefit near term infants. Time for a global rethink?


AllThingsNeonatal

1,683 views

cpap-premature.jpg.424c99897dd2c75c95c5a

What a hard topic to resist commenting on.  This was all over twitter and the general media this week after the New England Journal published the following paper; Antenatal Betamethasone for Women at Risk for Late Preterm Delivery.  The fact that it is the NEJM publishing such a paper in and of itself suggests this is a top notch study...or does it?

In case the idea of giving antenatal steroids after 34 weeks sounds familiar it may be so as I wrote about the use of such an approach prior to elective c-section in a previous post; Not just for preemies anymore? Antenatal steroids for elective c-sections at term.

Is there a benefit to giving antenatal steroids from 34 0/7 - 36 5/7 weeks?

That is the central question the authors here sought to answer. Would women who had a high risk of delivering during this time period have less risk of a composite primary outcome of treatment in the first 72 hours (the use of continuous positive airway pressure or high-flow nasal cannula for at least 2 hours, supplemental oxygen with a fraction of inspired oxygen of at least 0.30 for at least 4 hours, extracorporeal membrane oxygenation, or mechanical ventilation) or stillbirth or neonatal death within 72 hours after delivery.

On the surface this seems like a very worthwhile set of outcomes to look at and the authors found in the end some pretty remarkable findings in a total of 2827 women randomized to placebo or betamethasone.

composite outcome.png

Looking at the results one sees that the primary outcome showed a significant difference with 2.8% less infants experiencing these conditions. However, when one looks at the details the only contributor to this difference was the need for CPAP or HFNC for >= 2 hours.  A need for over 30% FiO2 for > 4 hours was also not different.  No differences were noted in mechanical ventilation, ECMO, deaths whether stillbirths or neonatal deaths.  Curiously, significant differences for secondary outcomes were seen with incidence of severe respiratory distress, and need for CPAP for over 12 hours.

These results are not truly that surprising at least for the primary outcome as if you asked most people working in the field of Neonatology how likely death, need for ECMO or even mechanical ventilation are from 34 - 36 weeks they would tell you not very likely.  The other thing to consider is that the only real significant difference was noted for infants needing CPAP or HFNC for at least 2 hours.  While this would interrupt maternal infant bonding, it wouldn't necessarily mean an admission but rather in some cases observation and then transfer to the mother's room.

Is it worth it?

To answer this question you need to know the best and worst case scenarios I suppose. Based on the reduction of 2.8%, you would need to treat 35 women with betamethasone to avoid the primary outcome but of course there is a range based on the confidence intervals around this estimate.  The true estimate lies somewhere between 18 - 259 to avoid the outcome.  Having said that, the estimate to avoid severe distress is 25 patients with a range of 16 - 56 which is pretty good value.  In a perfect world I would probably suggest to women that there seems to be a benefit especially if one notes that in this study only 60% of the women received 2 dose of betamethasone so if rates of administration were higher one might expect and even better outcome.  Ah but the world is not perfect....

There is only so much betamethasone to go around.

I find it ironic but the same day that this article came across my newsfeed so did a warning that we were about to run out of betamethasone vials in a certain concentration and would need to resort to another manufacturer but that supply may also run out soon as well.  The instructions were to conserve this supply in the hospital for pregnant women.

In Canada as reported by the Canadian Neonatal Network in 2010,  38.1% of babies admitted to NICUs were below 34 weeks.  Given that all babies would be admitted to NICUs at this gestational age and below that likely represents the percentage of births in those ages. An additional 31.8% or almost an equal number of babies will be born between 34 0/7 to 37 0/7 weeks meaning that if we were to start treating women who were deemed to be at risk of preterm delivery in that age range we would have a lot of potential women to choose from as these are the exact women in this strata who actually delivered early in Canada.

If I am forced to choose whether to give betamethasone to the mothers under 34 weeks or above when the resource we need is in scarce supply I don't think there is much choice at all.  Yes, this article comes from a reputable journal and yes there are some differences some of which are highly significant to consider but at least at this time my suggestion is to save the supply we have the babies who will benefit the most.

  • Upvote 1

1 Comment


Recommended Comments

I def agree with you.

BTW - around here (Stockholm county) the threshold for steroid induction is ≤32+6 weeks, i.e. pregnancies at 33 completed weeks are not induced. Although there is some discussion to extend the steroid window to ≤33+6 weeks, I just feel that extending treatment to all preterm births <37 weeks would be just too much. The majority of births occuring at 35-36 weeks are only nursed at the regular maternity ward, induction of these births with a drug that we cannot be 100% certain has no side-effects and has rel small benefits, that's risky medicine to me.

Link to comment

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...