Monday 5 August 2013

Miscarriage and infertility - why does it seem to go hand in hand?

Rates of miscarriage in infertile women are much higher than in the general population. So why is this? I have my theories and thought I would share them. These are only my thoughts, and I may be wrong, and happy to accept that too.

First thing to realise is that there are more than one type of loss.

The earliest loss is a chemical pregnancy. It normally happens before 6 weeks, and most women just assume they have had a late or heavy period, and never even know they were pregnant. That is, if you weren't trying. These pregnancy losses are also never recorded in the general population.

Chemical pregnancies happen more often in infertile couples because we look for them. We are trying to actively get pregnant and know when we do and we lose the baby. I actually think the rates are not much different - just not identified and documented like in the general population.

A miscarriage is before 20 weeks (to me that is crazy - stillbirth is very real before 20 weeks). If you have an early loss before about 14 weeks, chances are it is chromosomal. We see it more in infertile couples, because infertile couples can be older, have poor egg quality or low sperm counts. All these things can add to the chances of a chromosome mutation. Rates are higher, but from what I have read, a lot of the studies that are being done and quoted are either quite old studies or done in easy access populations like infertility groups. Again I think rates are higher due to a few factors, but also due to the way things are quoted.

I also think some of the technology is to blame. We are circumventing nature to some degree, through IVF, ICSI, IUI, drugs etc. We have no idea what all the crucial very early embryonic developmental stages are - we have a pretty good idea - but how do we know that by injecting sperm into the egg has not screwed up a development stage which has led to early embryos arresting in or out of the mother. We just don't know. But once again our miscarriage rates go up.

For late stillbirths after 20 weeks - these tend to be often due to a problem with the mother. I hate saying it - but it is important to understand. A shortening of the cervix, a badly placed fibroid, endometriosis causing havoc - there are lots of reasons, but I don't think it is any more common - unless the pregnancy problem is also related to the fertility problem.

At the end of the day, I think miscarriage rates are exaggerated in infertile couples due to risk factors (like age etc), monitoring of pregnancies from day dot (we know very early on if we are pregnant and lose it), and physical factors that may have affected the mother. With my first pregnancy I was so scared of miscarriage because I knew these factors. But at 34 I thought I had a great chance of coming out of it okay. I was a little bit more confident with my second at 35 - but I think age got me this time.

Not much I can do about my age - but I can try to improve my egg quality - so two days till detox time!

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