pat loughery

A human zygote

Part 2 of our little series.

I just spoke with the embryologist that will work with our case. His name is Doug, and he’s absolutely fantastic. He speaks plainly, clearly, but technically. He’s compassionate and reasonable.

During Shannon’s appointment with Dr. Kustin, she went upstairs to talk with Doug about the specifics of the process of freezing embryos.

Doug spoke with her and then on the phone with me. He cryogenically preserves pre-embryos, zygotes. The stage at which the freezing occurs is when the two nuclear envelopes containing chromosonal packages are not yet united, so they are pre-conceptive. Specifically, the chromosones have not united – and that is the moment of conception as defined technically by science.

That’s fascinating to me – and it also makes me comfortable to go ahead with the decision to freeze zygotes indefinitely – or, if need be, to discard unused ones. To me, that is analogous to discarding sperm and eggs.

An interesting side note in the process. I asked Doug why researchers were having problems freezing and recovering eggs. He described it this way: In the egg, each cell is in a different stage of maturity, so getting the precise timing is impossible. Specifically, there’s no good point at which they can stop the growth process, remove the water in the cell and replace it with an ‘antifreeze’ solution, and then restart the process later upon thawing.

However, in the zygote stage, both polar bodies enter a “rest phase”, gathering energy for the chromosonal mingling. The cells actually all shut down for a short while on day 1 – they pause. So there’s an agreeable stage to shut down and restart the process before/after cryopreservation.

So for now, the reason that cryopreservation of zygotes is much more successful than that of eggs is because the embryologists can take advantage of this specific moment in the process.

So I asked Doug to describe for me when he thinks life begins. He believes it begins at the moment of conception – that is, when the two nuclear envelopes combine chromosonal packages, which unite into a single new life form. That’s the technical definition of conception.

Our fertility specialist described that for him, life begins at the heartbeat – because a pregnancy is defined as beginning at the moment the heartbeat can be heard.

So… “Life Begins at Conception” – I’m more than ever convinced of that truth, after understanding much more about the cellular process involved.

And, I’m more than ever convinced of the greatness of God’s genetic engineering wisdom – imagine, a rest break that allows scientists to take advantage of the process in order to maximize the chances of fertility for a couple like us?