February 11, 2004

Valuing pioneering research

Recently, I was challenged about the relevance of referring to 25 year old research to support statements I was making in the Active Birth workshop - the implication being that anything that old was irrelevant and should not be used. This is an interesting topic to explore further.

The specific research being questioned was the work of Roberto Caldeyro-Barcia, who studied the effects on the fetus of prolonged breath-holding and closed glottis pushing during the second stage of labour (the so-called “cheer squad” pushing routine). He showed that this practice was dangerous because it had the potential to reduce blood flow to the placenta and to reduce the oxygen concentration of the blood that was available to the baby (both effects compounded if the woman is lying flat on her back to give birth). This pioneering work, done by an obstetrician who was, at that time, the President of the International College of Obstetricians and Gynaecologists, received widespread reporting 25 years ago, the result of his publishing in several journals and speaking at a number of Conferences. Sadly, his message does not seem to have penetrated some practitioners approach to birth, and this over zealous management of second stage still goes on.

Is a study, done so long ago, still relevant? Yes, of course it is. There seems to be a view, often drummed into midwifery students, that the only research that is relevant are studies that are less than three years old. Books and journals that are older than this are not considered appropriate and are discounted and taken off reading lists. This approach overlooks the huge body of work that was done many years ago and that does not need to be repeated: we know that it works/doesn’t work and we don’t need more funds spent on replicating this research. The Cochrane Library has a list of treatments or management strategies that are already proven beyond doubt to be either advantageous or dangerous. Interestingly, the placing of time limits on second stage (often the excuse for the “cheer squad” in the first place) is considered dangerous.

Michel Odent has written about “circular epidemiology” - the practice where the same studies keep being done because they give good results or are easy to undertake, even though the outcome is already proven. He also talks about “cul-de-sac” epidemiological studies - those that end up not being pursued further because the results might be unwelcome to practitioners. We’ve all come across yet another study on a topic that has been well proven in the past (the value of support during labour, for example). Doing further research on topics like this is a waste of precious resources and should be discouraged.

If academics and some practitioners maintain their stance that relevant evidence must be less than three years old, it leads to the conclusion that the entire body of research evidence needs to be replicated on a regular cycle - clearly impractical and wasteful. Many wonderful pioneering studies could be overlooked (the work of Caldeyro-Barcia falls into this category) and important research that need to be done could be quietly avoided (such as the effects of exposure of the unborn baby to nitrous oxide during labour - a topic that has never been investigated).

Keeping up with the research is hard work. It requires constant reading, dedication and an open mind. As we embrace the important work being published now, we must not overlook the valuable lessons from the past. Just because a reference has an “old” date on it, doesn’t mean it is worthless - many of them are in fact, priceless.

Calderyo-Barcia R. The influence of maternal bearing-down efforts during second stage on fetal well-being. Birth and the Family Journal, Vol 6:1, Spring, 1979.

Posted by andrea at February 11, 2004 10:48 AM

Comments

What a timely statement Andrea, good on you!!! I have been appalled to say the least at the adherence to active pushing in 2nd stage and the time line. To the extent of others coming in and instructing a women in active pushing when she has been doing a wonderful though slow job physiologically. Very wrong but authoritative statements about research often made to me later. It makes for a very difficult time in the labour ward.
mari

Posted by: Marilyn kleidon on February 15, 2004 08:26 AM

Comments

As a new graduate midwife in the country I have come across doctors and midwives encouraging women to push this way in second stage. At uni I was informed of the correct way a woman should push in second stage by a phsyiotharapist. When I encourage open epiglottis I have been challenged by doctors. It is good to see that this research has been around for years so that I can point it out to them.

Posted by: Julie Glass on April 16, 2004 10:46 PM