Tissue testing - 2nd miscarriage

[NphysT]

Hi all, little bit of background:

In December I had my 1st mmc 2 days after my 12 week scan, which showed a 1 in 2 chance of Down's syndrome. Had to wait 3 weeks for surgical management only to end up miscarrying the night before at home (January).

Got pregnant again in March only to have another mmc in April at 8 weeks (baby measuring 6 weeks). This was shown as a partial molar pregnancy so had surgery the next day. I also requested genetic testing and karyotyping because of my history which they did.

I got the results from the genetic testing yesterday and am hoping someone can help explain some parts to me. Will get a letter in the post which may offer some more information but this is all I have now:

Testing showed mosaic tetrasomy common in male pregnancy
Both me and my husband should get genetic testing done.

Can anyone tell me what exactly mosaic tetrasomy is? I've tried googling but am quite confused.
Does the male pregnancy mean our baby was a boy?
And has anyone had a positive result in genetic testing and gone on to have a healthy baby?

Thank you

Posting for traffic as my experience isn’t exactly the same, but I’ll share it anyway.

I had two consecutive MMC and had a few extra blood tests to look for antiphospholipid antibodies and anti-nuclear antibodies - but no genetic testing. Even though both were surgically managed, they only successfully collected tissue from one. Can I just add that it must have been torture waiting that long for management! My procedures were carried out within 48 hours on both occasions and I thought that was way too long as it was.

Did they really say mosaic tetrasomy?! Mosaic trisomy I know about (I’m a scientist by training). Healthy people have two chromosomes of each type (one from mum, one from dad) trisomy is where you have three instead of two of one of your chromosomes (usually two from mum, one from dad) with the most common trisomy where the child can survive to a fairly normal life expectancy being Downs.

Chromosomes are present in every single cell in your body. Mosaic trisomy is where some of your cells have three chromosomes and the rest have the normal two. If it’s a low proportion of cells that have three then you could go all through life without it ever having any effect at all and never even knowing.

Tetrasomy must have four chromosomes instead of two, and again “mosaic” means that only some cells have this problem.

They must be looking for whether either you or the father have any unusual numbers of chromosomes to see whether it’s likely to happen again or whether it just happened as a one off strange event in your pregnancy.

Hope that’s helpful? I’m happy to try to explain any technical terms if it helps.

Hi, thank you for your reply. Your explanation was really helpful.

Yes, I'm pretty sure they said mosaic tetrasomy. I'm assuming this is because it was already a partial molar so that's where 2 sperm fertilise with the egg so there were already 3 lots of chromosomes.

Hoping when I get the letter from the hospital it will shed some more light on it.

Thank you again.