Should I take clexane?

Dear Professor Winston,
I am a 45, in good health (non-smoker, exercise regularly, BMI ), and have been undergoing IVF for the last 18 months using donor eggs from a well-known fertility clinic in the UK. I have an anteverted uterus and multiple fibroids, the largest of which are 9.8 cm intramural and submucosal 7 cm; none in the uterus itself, I am told. I have had these as thoroughly investigated as possible (hysteroscope, MRI), and the result was that I was told to proceed without treatment of the fibroids.
I have had embryo transfer twice, both of which were unsuccessful (one miscarriage at 6 weeks and one chemical pregnancy). After the second I then followed the advice of the clinic and had Level 1 implantation screening blood tests done (general health, thyroid function, and full thrombophilia screen with autoantibodies). (They also advised Level 2 tests but I read up on these and saw that they seem to be controversial, not to mention extremely expensive, so I decided against them).
The results of the Level 1 tests were that I have heterozygous gene mutation MTHFR, and homozygous mutation (4G/4G) of PAI-1.
I was advised to take Pregnacare max for the folic acid deficiency, and aspirin and Clexane throughout any future IVF treatment and pregnancy (to 8 weeks after any delivery). The clinic also said that while this is their advice, it is not something that GPs/ obstetricians routinely prescribe, and that I might therefore have to fight to get it prescribed if I were to get to that stage in proceedings.
My question is this: would you advise Clexane in these circumstances, or would aspirin be enough? I am very concerned indeed about what I read about Clexane (the painfulness of injections of possibly 11 months; how it might affect me if I were in an accident; what the implications of taking it might be for delivery/ C-section); conversely, I’m also worried about a scenario where I do screw up my courage to take it, and then have to stop taking it because the NHS won’t prescribe it (what might the consequences of this be for me and for the baby?) I’m also pretty unclear about whether the clinic are saying I really should take this, and if so, on what grounds.
In short, I’m stuck. Would it be foolish to proceed without Clexane in my case? Or are there other factors I should be bearing in mind?
Thank you so much for any advice you can give. C.

Dear C,

I don’t think I fully understand your enquiry. I cannot help observing that it seems odd to look for rare conditions as a remotely possible cause of your infertility, or consider expensive and totally unproven treatments, when almost certainly the real cause of the problem seems (at least to me) to be staring us in the face. For example, submucosal fibroids are by definition in the uterus itself.

With regard to the mutations you describe (and by the way all of us have hundreds of mutations which are nearly always largely irrelevant to our health and well-being) the heterozygous one would seem irrelevant unless clearly you have some evidence of disturbance of amino acid metabolism. The other mutation might be relevant – but I think you will find that there are numerous people with disturbance of plasminogen activator or fibrin metabolism who conceive normally. It certainly is very unclear whether Clexane is truly effective.

There’s an old adage in medicine – common problems occur commonly. We should not be too easily seduced by the vague promise of high tech treatments or sophisticated therapies which have limited proved value except just possibly in a very few cases. People with the extremely common problem that you seem to describe – a uterus with an apparently anatomically disturbed as yours frequently have great difficulty with implantation for all sorts of reasons. Clearly on such limited information I cannot guess (and it is only a guess) more than this, but of course I would be happy to give you whatever advice I can.

For a start, I am happy to look at digital images of your MRI if you like.

Best wishes
Robert Winston