Baby's 1st 10 weeks: A Prenatal Primer

Here's what we missed over the past 10 weeks (loosely based on information culled from the Mayo Clinic Guide):

Week 1-2: Fertilization and Conception

Approximately four months after going off the Pill, Anna's body begins producing follicle stimulating and luteinizing hormones. A small cavity in her ovary, the follicle, swells and bursts through the ovary wall, releasing an egg. The egg begins a slow journey into the fallopian tube, where it's captured by "finger-like structures" called fimbriae. There it lies in wait for one of a billion or so of my boys to show up and finish the job. They call this period "preconception." Think of it as the calm before the intrauterine storm.

In the interest of maintaining the family-friendly atmosphere of this blog, and since both our moms are probably reading this, I won't go into graphic detail about the process of insemination. Suffice to say my little swimmers find their way into Anna's reproductive tract and make a beeline for her awaiting egg: into the vagina, through the cervix, beyond the uterus to the fallopian tube. Hundreds of millions of brave little guys die before ever reaching this point, but a plucky few arrive at the egg, and one tenacious sucker penetrates the corona radiata and zona pellucida and voila! Fertilization! At this point, our baby is but a zygote, a one-celled bundle of 46 chromosomes containing the genetic material that will dictate everything from biological sex to eye color, and which have already pretty much determined he or she will never play professional basketball. Such is the miracle of conception.

Week 3-4: Implantation and Early Development

Within 12 hours of conception, the process of cell division begins. The zygote doubles in cellular mass every 12 hours thereafter as it moves from the fallopian tube into the uterus. After three days, our busy little zygote has become a morula, "a cluster of 13 to 32 cells resembling a tiny raspberry." In a few days more it will be a blastocyst, comfortably imbedded in the cozy endometrium of Anna's uterus. They grow up so fast, don't they? Before long, I'll be handing him or her the keys to the car and nervously contemplating the skyrocketing cost of college tuition.

Week 5: Hello, Embryo!

During the 5th week of pregnancy, our budding baby has put aside blastocystic things and developed an embryonic fascination with cell differentiation. Its ectoderm has begun to form a neural tube, which will eventually become our baby's nervous system. Its mesoderm is beginning to form a heart and circulatory system. Its endoderm, which will eventually become lungs, intestines, and a urinary bladder, is pretty much dormant at this point. What do you expect? It's a friggin' embryo. Cut it some slack.

Week 6: Slow down there, Tiger.

During this busy week, our baby triples in size, basic facial features are becoming visible, the neural tube has closed and a brain is beginning to form. A miraculous brain with a virtually infinite capacity for creativity and understanding of the complex universe into which our baby will be born. Or so we'd like to think.

Week 7: It's a boy! And he's hung like a bear!

During week 7, the umbilical cord becomes visible. One wonders if Robin Williams is the only expectant father to mistake the umbilical cord for another "vital organ."

Week 8: Now they tell us

Eight weeks into the pregnancy, our baby's development continues apace: tiny arms and legs are growing longer and more defined; eyelids are forming; ears, lips and a nose are almost recognizable. But that's not the important part. It's at this point in the Mayo Clinic Guide that they decide to tell us about the "Early Hazards to Your Baby's Health." Teratogens, infections, radiation, poor nutrition - these are but a few of the many hazards that threaten to derail the pregnancy. If the purpose of this little bit of information is to instill paranoia and irrational fear, mission accomplished. It doesn't help that they emphasize our baby "is most vulnerable during the period from three to eight weeks after conception." We didn't even know Anna was pregnant for another two weeks. Fantastic. I need a teratogen.

Week 9: Congratulations - It's a humanoid!

In week 9, our baby begins to look less like a tadpole and more like a human. The embryonic tail at the base of the spine is shrinking, hands and feet are sprouting fingers and toes, and the endoderm has finally gotten into the act: a pancreas, bile ducts, gall bladder and anus have formed. That is so gross. Miraculous, but gross.

Week 10: See Figure 1 - Baby's 1st Sonogram

It's at this point that we found out Anna is pregnant. Vital organs have formed, embryonic tail has disappeared, and fully separated fingers and toes are visible. The brain is growing quicker, at the astounding rate of 250,000 new neurons per minute. And if it's a boy, his testes will begin producing testosterone. This could explain why Anna has the distinct feeling it's a boy.


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