All About the First Trimester of Pregnancy | Fit Pregnancy

All About the First Trimester

For most women, the first 12 or so weeks of pregnancy are the most consuming because everything is all so new, so exciting, even overwhelming. To satisfy the little voice inside your head that keeps asking questions, here's a primer. Keep it handy.


Telling People
Deciding when and with whom to share your news is a very personal decision, but there are a few things to consider. Keeping your pregnancy a secret for a while will give you and your partner some time to absorb the idea privately. While some women wait until the risk of miscarriage drops markedly (at 14 weeks), others spill the beans right away because they’d tell their friends anyway if they miscarried. Telling co-workers is trickier.

You may find that your employer expects the news to be followed by the details of your maternity leave, but you may not have decided yet when to return to work—if ever.

Most obstetricians will perform an ultrasound at your first prenatal visit to confirm your pregnancy and to date it if you don’t know when you conceived. Later on, you’ll probably have a transabdominal ultrasound (like the ones you see on TV), but the early exam may be performed by inserting a plastic wand into your vagina. (Don’t worry—it doesn’t hurt.)

Weight Gain
While the average weight gain during the first trimester is about 5 pounds, some women actually lose weight because of morning sickness and food aversions. If it happens to you, don’t panic: You’ll soon see the numbers on the scale climb.

Just remember that pregnancy is not the time to go on a diet, but rather to eat as healthfully as you can (some women prefer eating six small meals throughout the day). “Anytime you deprive your body of the nutrients it needs, it has to rob them from someplace else,” explains Low. That means invading emergency stores of calcium or iron, for example.

X and Y Chromosomes
The sperm determines the baby’s sex. Here’s how it works: The egg and sperm each contribute one chromosome. The egg always carries an X; the sperm, either an X or a Y. If the fertilizing sperm contains an X chromosome, you will have a girl. If it contains a Y, you’re having a boy.

The fertilized egg, also known as a zygote, is the size of an apple seed when you can confirm that you’re pregnant—about two weeks after conception. By week five, it’s known as an embryo, and the placenta and umbilical cord are functioning. At eight or nine weeks, it’s officially a fetus and all its organs have been formed.

By the end of the first trimester, it’ll be almost 3 inches long and the face will look recognizably human. No wonder you’re tired!


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