Well, my fantasy remains pretty outlandish, but it turns out that there is a way to look at the genetic make-up of the egg before it is fertilized. I just wanted to make sure it had the proper number and right kinds of chromosomes but it can also be used to look into more specific things. The main reason it is used is to make sure that the egg is viable before implantation. This can cut back on the number of embryos they have to implant after in vitro fertilization in the hopes of having a healthy baby and hopefully, reduce the number of women who go from not having any baby at all to having four all at once.
The way it is done is to take the polar body out of the egg and do genetic testing on it. You might remember that in the process of reducing the number of chromosomes to half that of a regular cell, the egg produces these little things called polar bodies. Normally they disintegrate after the egg is fertilized but they contain the mirror half of the chromosomes that are in the egg. If there are any chromosomal abnormalities, you'd be able to tell from the polar body.
Of course, not everybody can afford IVF in the first place, but for those that can this might be a way to ensure that a woman my age (36) has a healthy baby. Most of us will probably just have to muddle along with nature and hope for the best... at least for now.
Links:
An abstract from a study about a possible function of polar bodies.
All about meiosis: scroll all the way down to see oogenesis.
Word Of The Day
gemetogenesis: The making of gametes. Gametes are the sex cells, or eggs and sperm. Sometimes you hear this referred to as spermatogenesis or oogenesis, meaning egg or sperm production. They are not produced in exactly the same way, which makes sense if you think about it. Eggs are large and have lots of cytoplasm. For the first divisions after fertilization there is no time for growth, so you end up with lots of cells the same size as the original egg. Sperm are little and have flagella so they can swim and find the egg. They don't contribute much (just the chromosomes they carry) to the size of the fertilized egg.
2 comments:
It still kinda scares me to see all these multiple births that happen from fertility treatments.
From zero kids to 3, 4, 6, 8... in nine short months.
The poor, poor mom and dad will soon forget what peace and quiet sounded like.
As the mother of a single child I can hardly imagine it. Also, having more than two at a time puts all of the babies at a much greater risk of not making it to term. To spend all of that time and money in a desperate attempt to have a baby and then lose six babies all at once... That would be really heart breaking.
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