Saturday, August 17, 2013

Unbalanced.

The next few weeks following the news that my recent pregnancy was lost due to a rare Trisomy were a fog.  As you've figured by now, reproduction for me is like an old movie set, in Victorian-era London, with the copious use of a smoke machine.  We learned that there would be one of two outcomes: a) this is a random "de novo" event, and my recent loss is the result of some more unfortunate luck, or b)  There is an "explanation" to my problems:  my husband is a carrier of an inherited chromosomal abnormality called a Balanced Translocation and I will continue to lose babies because of it.

So what does a girl facing a potentially rare chromosomal defect that causes miscarriages do?  Join a support group of course!

The Balanced Translocation (BT) support group is one smart group of ladies (and a few rare gents who like to discuss their feelings with the virtual world).  Some are women who have survived as many as 8 miscarriages.  Others are women who have discovered -  after having one completely normal pregnancy -  that they can't conceive a healthy baby the second time around. All of the group's participants have been through a special ring of hell called Repeat Pregnancy Loss (RPL). 

BT is a game-changer.  Some couples turn to IVF with genetic screening to try and cull out only healthy eggs - this may or may not be covered by insurance (more than likely not). Others stick it out and brace themselves for multiple miscarriages - three, four, five, ten(!) -  in pursuit of a healthy baby.  Because BT turns out to be a game of reproductive roulette. 

I learned a lot about statistics the next few weeks.  The best explanation of BT, and the potential translocation my husband carried, was found here:
http://www.rarechromo.org/information/Other/Balanced%20translocations%20FTNP.pdf

Another awesome attempt at genetics comes from this blogger, who helpfully uses playdough to illustrate her husband's BT.
http://julia.typepad.com/julia/2005/05/balanced_transl.html

The bottom line is that when you or your partner carry a genetic translocation, you have at least a 50% chance of conceiving a baby that is "unbalanced" - this means severe disability, often so severe that the baby won't survive the pregnancy, let alone the outside world.  This is what accounts for the high miscarriage rate in its carriers.  You then have something along the lines of a 25% chance of conceiving a baby who carries the chromosomal defect but is otherwise perfectly healthy (though prone to their own miscarriages when they later reproduce).  And then there's something like a 25% chance of having a baby that is "perfect" a non-carrier.  All of these numbers are rough estimates and the outcomes hinge on the specific kind of BT carried, along with too many other factors for me to wrap my humanities-driven brain around.

Carriers of BT have to face horrifying and calculating decisions on a daily basis.  Do I keep ttc naturally?    Do I turn to IVF to try to cull more healthy eggs?  Do I undergo CVS and amnio despite their miscarriage risks?  Do I terminate a baby who is unbalanced? What are my parameters for stress and grief?  At what physical and emotional price to I continue to push my body's limits?

These decisions consume me for the next few weeks as we wait for Husband's lab work to come in.  All I can do is hope that our baby's T-14 was "de novo" - a one-off defect that wasn't inherited.  I am no longer hoping for an explanation on my pregnancy loss because the explanation is terrifying.  Wow. I am actually hoping for more bad luck.

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