The Biology of Pregnancy with a Donated Embryo

I thought this was a beautiful read...and while it was written about using donated eggs, it totally applies to donated embryos. It was written by Cara Birrittieri and it is a list of myths she seeks to dispel...I'm listing the third one since that is the most powerful to me. Reading this made me feel even more excited about the prospect of using embryo donation for us. The booklet in it's entirety can be found here: http://www.fertilityneighborhood.com/bin_web/images/uploaded/DonorHandbook_ForWEB_v1.pdf

You probably learned the following in your high school biology class, but most of us need a review to dispel many of the myths around baby making and making a baby with a donated egg. To create an embryo that will grow into a healthy child, you need genetic material from two different gene pools. The combined genetic material instructs the developing fetus to become a boy or a girl, tall or short, have curly hair or straight, blue eyes or brown.
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Myth number 3: Perhaps the greatest myth surrounds pregnancy. Many believe the uterus is simply an incubator. Nothing could be further from the truth. The most important aspect of all pregnancies — including egg donation pregnancies — is that as the fetus grows, every cell in the developing body is built out of the pregnant mother’s body. Tissue from her uterine lining will contribute to the formation of the placenta, which will link her and her new child. The fetus will use her body’s protein, and then she will replace it. The fetus uses her sugars, calcium, nitrates, and fluids, and she will replace them. So, if you think of your dream child as your dream house, the genes provide merely a basic blueprint, the biological mother takes care of all the materials and construction, from the foundation right on up to the light fixtures. So, although her husband’s aunt Sara or the donor’s grandfather may have genetically programmed the shape of a new baby’s earlobe, the earlobe itself is the pregnant woman’s “flesh and blood.” That means the earlobe, along with the baby herself, grew from the recipient’s body. That is why she is the child’s biological mother. That is why this child is her biological child.

Many recipients ask, “Is the baby actually my flesh and blood?” Not literally. No baby is really its mother’s flesh and blood because the truth is that every fetus builds its own flesh and its own blood. Still you might wonder, “If it was my own egg, wouldn’t the baby then have my blood?” No. The baby might inherit your blood type, but would still be making its own blood, just as it makes its own skin and hair texture, and nails and teeth. Besides, with or without egg donation, the baby might have inherited his or her blood type from the father’s gene pool.

Think of it this way: every baby is a complete, self-contained, unique human being. You will meet this person when he or she is born. To try to sort out the genetic contributions at that point is like trying to break a cake down into flour, sugar, water, and yeast after it has been baked. It is now a cake, no longer separate ingredients.