The Baby Bean Blog

Friday, December 17, 2004

Week 5 Progress Report

You, my little bean, have been very busy, and what you have accomplished has been nothing short of a miracle considering that you have only been around for three weeks! According to traditional medicine, my pregnancy started when my last menstrual cycle started, so I think I'll start this post there as well.

People make a big deal about the amazing sperm race, and I have too. But there's also another race, another choosing process that begins beforehand, and that is for the lucky egg. The journey of the egg that helped create you began on November 11th. Many eggs volunteered themselves, but only the best one would beat out the others and get ovulated sixteen days later on November 26th, 2004, the day after Thanksgiving. That was the day that you were conceived, as tens of millions of sperm swam around looking for that egg. Eventually, a few hundred would find the egg, but only one would have the wherewithal to make it through the egg's shell and combine its 23 chromosomes with my egg's 23 chromosomes, and that combining looked something like this:



A fertilized egg (zygote) at high magnification. Male and female genetic material (DNA) is in the 2 pronuclei (circles) in the center.

From there, you divided into two cells.



Then four.



Then eight (only six cells can be seen from this angle).



Before becoming a "morula."


This is a compacting morula. There are many cells and the cell borders are becoming fuzzy as the embryo "compacts."

You kept dividing every 15 hours, becoming less and less solid and more filled with liquid until you became a blastocyst.


A high quality human blastocyst. The developing fetus itself is the area marked as "ICM" (inner cell mass). The blastocoel cavity in the center is marked as "C." The trophectoderm cells that will form the placenta surround the cavity - one is marked with a "T."

And all of that within 5-7 days!

But you weren't done. No, you are far from done. In the next fourteen days, you kept changing and evolving. Somewhere around the eighth day after conception, you were up to 100 cells, and you started to implant in my uterine lining. The outer wall of the blastocyst dug into my endometrium and started to receive nourishment from it, giving you the strength and energy to keep on your amazing journey. As soon as you set yourself in my lining, you let the rest of my body know you were there by releasing hCG (human chorionic gonadotrophin), the pregnancy hormone. My body reacted and took steps to ensure that I would not get my period...and you started making me feel a little nauseous.

Just like you did about 40 hours after the sperm fertilized the egg, you, the blastocyst, again divide in two. The outer layer, the one attached to my uterine lining, will become the placenta and the umbilical cord. The inner layer will become you.

After that was done, the inner layer, you, divided into three "germ" layers. The outer layer, understandably, will become your skin and hair, as well as your brain and nervous system. The middle layer will become your kidneys, bones, blood vessels and muscles. The inner layer will become your digestional tract, liver, bladder, etc. And you've done all that in just two weeks!

This last week, you've started even more changes. You are no longer a ball of cells, but you've started to elongate. You've got a big head and a tail. You're focusing on developing your nervous system, concentrating on your brain and spinal cord. Your eyes and ears are coming along, and some of your internal organs are starting to develop, including the liver and kidneys. And your heart is also getting started...and even beginning to beat.

You, my baby, are amazing. I can't believe how hard you've been working! Right now, your placenta is still too small and underformed to provide you with the nourishment you need to keep going at such a manic pace, so I am trying to be good and eat all the right foods so that my endomitrium will provide you with everything you need. I can't believe how much you've accomplished, and I can't wait to meet you in 35 weeks!


  • (All of the pictures and the hyperlinked descriptions of the pictures are taken from the website of the Advanced Fertilty Center of Chicago, which specializes in in vitro fertilization.)

  • Also, I learned all the facts about the development of the embryo from The Pregnancy Bible. (Link in sidebar.)
  • 2 Comments:

    • This site's gonna be one hell of a baby book. Make sure you've got it backed-up so that you're kid can look at it all one day and think...

      "Who the hell is Fyse?!"

      By Blogger Fyse, at 5:48 PM, December 17, 2004  

    • Thanks, Fyse. Kind of like you were saying on your blog, explaining things to others makes your own understanding more solid.

      And my kid won't be the only one wondering, "Who the hell is Fyse?!" I often wonder that myself. :)

      By Blogger Oz, at 9:44 AM, December 18, 2004  

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