Taking shape: The anatomy of your 9 months (Part 1)

By Published On: February 1st, 2011

In the 40 weeks of pregnancy, your body undergoes some serious changes—both inside and out. Before you even see those two little lines, your body is busy building the perfect environment for your budding baby. What exactly is going on in there? Here’s a breakdown of what you can expect, trimester by trimester.
First trimester (1 to 13 weeks)
While you might not be able to tell that you’re pregnant by looking in the mirror, your body will begin to undergo subtle changes during the first three months that will serve as daily reminders of your mommy-to-be status. Your waistline may remain as svelte as it was prepregnancy (you’ll probably only gain 2 to 5 pounds), but your first trimester welcomes growth in other areas as your breasts swell and uterus expands to accommodate your tiny peanut.
The weeks following conception can give way to a few less-than-fun side effects of pregnancy. Morning sickness—which, despite its title, doesn’t only occur in the morning—can result in nausea and vomiting. On top of feeling icky, most moms also report being abnormally tired. You can blame these problems (along with some serious mood swings) on your fluctuating hormones. The combination of hormones, fatigue and tummy-upset could also lead to a decreased sex drive. Once your body settles in and gets used to the changes it’s experiencing, most of these issues will likely dissipate.
What to expect: Morning sickness and mood swings
Your baby: The tiny embryo inside you is growing organs and tissues and will soon be recognizable as a human baby. His heart begins to beat, and his eyes, nose, ears and appendages start to form. He even has fingerprints!
(Click here to continue on to second trimester.)