Dear Professor Winston
I am writing for your advice because I have suffered 5 early miscarriages: 1 in 2005 (an unplanned pregnancy with previous partner) and the 4 in the last 2 years. I am 32 and healthy, aside from mild eczema and asthma. Following the 3rd miscarriage, my husband and I had testing for common causes of miscarriage including Anticardiolipin, Factor V Leiden, MTHFR mutation, protein C and S, thyroid function, FSH, LH, Vitamin D and karyotype analysis. All results were normal. I also had a 3D scan which showed a uterine anomaly and a unicornuate uterus was confirmed by an HSG and MRI. I have been advised that my unicornuate uterus is not a contributing factor in the recurrent miscarriages. Do you think there are there any other tests it would be worthwhile undergoing to try and find a cause for the miscarriages? I am tempted to be tested for high NK cells but I am concerned about the lack of scientific evidence indicating a link with recurrent miscarriage. Assuming no cause is found, we will have to make a decision about whether to continue trying for a baby as the miscarriages are taking their toll. Are there any statistics you are aware of that would assist us with this decision, such as the likelihood of a successful pregnancy with a history of 5 early miscarriages? I’m not sure whether it is relevant but two of the miscarriages were very early (during the 4th week) and the rest were missed miscarriages diagnosed at around 8 weeks due to lack of a strong heartbeat and required ERPCs. Any advice you are able to give would be gratefully received. Yours sincerely L.
I would be extremely surprised if the unicornate uterus is not the cause of your miscarriages. Obviously I haven’t seen your X-rays or been given the dimensions of your uterine cavity but it seems improbable to me that there is any other likely cause. The only thing against this is that your pregnancy losses have all been very early in pregnancy but even so this must be the most likely reason.
The dimensions of your uterine cavity are important. Sadly, whilst I have operated successfully on many variations of uterine abnormality, I know of no surgical interventions which will improve this. But I must say to you after years of experience with a wide range of uterine malformations, occasionally recurrent pregnancies in people with a unicornuate uterus go a little further in successive conceptions. If this is true in your case it may be worth the severe psychological upset to keep trying. I don’t underestimate what this may mean to you but I have seen one delivery after 17 miscarriages with a single-horn (unicornuate uterus). But you may feel this is just too difficult to contemplate on the off-chance you succeed eventually. The other possibility, of course, is surrogacy but again, this is a massive step with all kinds of emotional, social, financial and legal issues. But it is legal in Britain providing the surrogate is not paid large sums of money.
Dear Professor Winston
Thank you very much for your speedy reply and the advice given.
I must say, I thought it was strange that the unicornuate uterus was not attributable to the miscarriages in some way.
I don’t wish to take up too much of your time but I would be extremely grateful if you could explain or direct me to some information about the underlying reasons behind a unicornuate uterus causing early miscarriages? Almost all the information and advice I’ve received so far has said that I should only be at risk of problems later in pregnancy and I would like to be able to discuss the unicornuate uterus’ role in my early miscarriages further with my doctor.
Many thanks again for your advice, L.
Of course a uterine malformation matters. With unicornuate uterus, pregnancy loss is most likely where the internal length of the uterine cavity is less than 6.0cm, but can occur at any length. It is also rather more likely if the cavity measures much over 8.0 cms. Also you may be getting pregnant in a rudimentary horn on the opposite side if the tube on that side is patent – in which case early miscarriage is probably inevitable. I repeat that in my view an x-ray (which is cheap) is essential.
I am sorry that you needed this extra information; your doctor can look it up in the research literature if needed.