05 March 2010

Healthcare corner #9 - Research on pregnant women

went to an interesting talk at the dalhousie law school today.

again, i'll try to be brief. this was a talk by researcher françoise baylis called "pregnant women and the H1N1 vaccine." her general interest is in arguing for pregnant women to be included in clinical trials for drugs/interventions that could be needed or of use to women during their pregnancy. she chose the recent H1N1 vaccination situation as an example.

so, in this past flu season there were a number of strategies employed in different countries for getting the vaccine out. since it is known that the flu in general, and this H1N1 strain in particular, put pregnant women at increased risk of serious complications and death, it was important for them to be recommended for vaccination. unfortunately, there was a muddled message presented to the public due to the lack of "gold standard" information involving pregnancy and vaccines.

she mentioned that in the u.s. the vaccine strategy was to purchase enough vaccine for high risk groups only (which included pregnant women) and to buy the inactivated, unadjuvanted virus vaccine only. in the u.k. the vaccine strategy was again to purchase enough vaccine for high risk groups only (which included pregnant women) but they recommended the adjuvanted vaccine to pregnant women. in canada, the strategy was to purchase enough vaccine for everyone who wanted it to be injected (however, they would roll it out in waves to get the high risks groups taken care of first). originally, they only bought the adjuvanted type of vaccine and then later bought the unadjuvanted and told pregnant women that that was the one recommended for them because the adjuvanted type lacked safety information for pregnancy. the result was confusion and fear due to the governments own confusion and mixed messages (also seen in other countries this past flu season).

the major issue is that vaccines (in general, not just this past flu season) have not been tested on pregnant women in the traditional sense. normally before something is approved for use in a population, it is tested on a sample of people and the FDA approves it for specific uses (to paraphrase). pregnant women have always been a scary, taboo population to want to test anything on for obvious fear of harming the fetus. but this presents an interesting issue: are we actually doing more harm by not specifically testing on pregnant women in initial clinical trials?

to be more clear: for example, in the u.s. from 1941-1971 it was common for pregnant women to be given DES because it was a drug that was supposed to prevent miscarriages. it was originally approved for use in other populations of people (menopausal symptoms, vaginitis) but doctors found there was this added benefit of being able to prevent miscarriage so they started prescribing it in this new population (called "off label" use). some 5-10 million people were exposed (both in-utero and the pregnant women themselves) to DES which ended up causing major reproductive/fertility problems and an increased risk of cancer. these women were basically socially experimented on and it took 30 years to discover the link between the drug and these abnormalities and to stop its usage.

another example is the drug thalidomide. it was used in nations worldwide (including canada and the u.s.) from about 1957-1961, its effects were so severe that they were noticed much more quickly. the drug was given as a sedative and morning sickness aide to pregnant women (although, again, it was originally approved for use in other populations). the effects on the fetus were severe with more than a few dozen possible negative implications (cancers, digestive tract development problems, blood vessel problems, eye problems), not the least of which were malformed limbs.

anyway, this speaker then briefly mentioned the history that all our medication/intervention knowledge from experiments used to come from study populations involving only healthy, white males. in the 1980s, researchers and other advocates finally got children into experiments so that again the safety could be tested on them in a controlled environment and real, tested results could inform drug recommendations for kids. and in the 1990s, women were finally included in clinical trials. this may seem crazy, but thats the history. and this is why the speaker advocated for responsible, controlled testing of the drugs/vaccines/interventions that pregnant women are likely to need to use during pregnancy.

for example, a pregnant woman who is diabetic/epileptic/depressed, etc. is going to still need to take her medication while she is pregnant. the effects of diabetes or seizures would likely be more harmful to her and the fetus without the drugs. but, these drugs need to be tested in this population. currently they have not been. all the information we have on medications and vaccines for pregnant women is accumulated through historical information, which can definitely be used to define something as "safe" or not...the problem is that it takes years/decades to build up this information.

in the case of vaccines, they have been around long enough, and used on millions of pregnant women, so compiling that data and analyzing it does show that vaccines are safe and effective for use in pregnant women. but, it took this H1N1 situation to show us that there is still a widespread misunderstanding of the issues surrounding the information we have available and what kind of standards governments should require before they can be confident to recommend use in vulnerable populations. in the u.s., they were actually spurred on to begin a national study including pregnant women in trials of vaccines. it looks like they will be the front runners to getting this population much needed information in the more traditional "gold standard" type way. kudos.

and to end with something related, but not from the talk, i was really fascinated to have recently seen the news that the infamous 1998 study that suggested the link between vaccines and autism has been retracted. printed in one of the most famous and respected medical journals in the world, every single author involved in the "research" has denied the findings. apparently the lead author was paid by groups of concerned parents with autistic children to find a link between the two, and "find a link" he did. he freaked out millions of parents and changed the landscape of childrens health for who knows how many years into the future. numerous studies have come out since 1998 saying they could not find a link to autism, and now this retraction is added to the pile. however, it saddens me that it has probably irrevocably damaged vaccines in peoples minds. when it comes to medical things, nothing is 100% safe, so im not suggesting vaccines are perfect, but they have certainly been massively important for saving millions of lives over the decades with minimal negative effects.

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