Week 8!

Our baby is now 5/8 of an inch long, about the size of a kidney bean. She's constantly moving and shifting, although I won't be able to feel these womb wiggles for several weeks yet. Her embryonic tail is disappearing, and her eyelids practically cover her eyes. Still slightly webbed, her fingers and toes are growing longer. Her arms have lengthened, too, and her hands are now flexed at the wrist and meet over her heart. Her knee joints have formed, and her feet may be long enough to meet in front of her body. With her trunk straightening out, her head is more erect. Breathing tubes extend from her throat to the branches of her developing lungs. The nerve cells in her brain are also branching out to connect with one another, forming primitive neural pathways. The external genitals still haven't developed enough to reveal whether you're having a boy or a girl.

Week 7!

Our baby still appears to have a small tail (actually, it's an extension of his tailbone), which will disappear in the next few weeks. But that's the only thing getting smaller. Now almost half an inch long — roughly the size of a raspberry — he has elbow joints and distinct, slightly webbed fingers and toes. In his oversized head, both hemispheres of his brain are developing. His teeth and the inside of his mouth are forming, and his ears continue to develop. Eyelid folds partially cover his tiny peepers, which already have some color, and the tip of that nose we'll be tweaking someday is emerging. His skin is paper-thin and his veins are clearly visible.

Our little one also has an appendix and a pancreas, which will eventually produce the hormone insulin to aid in digestion. His liver is busy producing red blood cells, and a loop of your baby's growing intestines is bulging into his umbilical cord, which now has distinct blood vessels to carry oxygen and nutrients to and from his tiny body. I can't feel his gyrations yet, but our baby is like a little jumping bean, moving in fits and starts around his watery home.

Week 6!

The cells that will make up all of our baby's body parts and systems are dividing furiously as her body begins to take shape. Right now she's about the size of a small lentil bean (4 to 5 millimeters across). If you could see through my uterine wall, you'd find an overlarge head and dark spots where her eyes and nostrils are beginning to take shape. Shallow pits on the sides of her head mark her developing ears, and her arms and legs appear as protruding buds. Her hands and feet look like paddles, with thick webbing between the developing digits, but her fingers and toes will soon become more distinct. Below the opening that will later be our baby's mouth, there are small folds where her neck and lower jaw will eventually develop. (Inside, her tongue and vocal cords are just beginning to form.)

Our baby's heart (which is starting to divide into the right and left chambers) is beating about 100 to 130 beats per minute — almost twice as fast as mine — and blood is beginning to circulate through her body. Her intestines are developing and tiny breathing passages are beginning to appear where her lungs will be. She's also starting to build muscle fibers and, halfway through this week, she'll likely start moving her tiny limbs. Unfortunately, I'll probably have to wait until I'm several weeks into my second trimester before I get to enjoy feeling our baby's calisthenics.

We Are Pregnant!

This was Dan's reaction the second we found out we were pregnant!

Week 5!

Deep in my uterus my embryo is growing at a furious pace. At this point he's about the size of a sesame seed, and he looks more like a tiny tadpole than a human. He's made up of three layers — the ectoderm, mesoderm, and endoderm — that will later form his organs and tissues. The cells are forming for his major organs, including his kidneys and liver, and his neural tube is beginning to develop. This neural tube — from which our baby's brain, spinal cord, nerves, and backbone will sprout — develops in the top layer, called the ectoderm. This layer will also give rise to his skin, hair, nails, mammary and sweat glands, and tooth enamel. His heart and circulatory system begin to form in the middle layer, or mesoderm. (This week, in fact, his tiny heart begins to divide into chambers and beat and pump blood.) The mesoderm will also form our baby's muscles, cartilage, bone, and subcutaneous (under skin) tissue. The third layer, or endoderm, will house his lungs, intestines, and rudimentary urinary system, as well as his thyroid, liver, and pancreas. In the meantime, the primitive placenta and umbilical cord, which deliver nourishment and oxygen to our baby, are already on the job.

Week 4!

This week marks the beginning of the embryonic period. From now until ten weeks, all of our baby's organs will begin to develop and function. As a result, this is the time when she'll be the most vulnerable to anything that might interfere with her development.

Right now your baby is an embryo consisting of two layers: the epiblast and the hypoblast, from which all her organs and body parts will develop. The primitive placenta is also made up of two layers at this point. Its cells are tunneling into the lining of my uterus, creating spaces for your blood to flow into so that the developed placenta can provide nutrients and oxygen to your growing baby when it starts to function at the end of this week. Also present now are the amniotic sac that will house our baby, the amniotic fluid that will cushion her as she grows, and the yolk sac that produces our baby's red blood cells and helps deliver nutrients to her until the placenta is ready to take over this duty.