pregnancy | week by week

Fertilization

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Week 3: Fertilization

A little zygote forms.

Although you don’t know it yet, you might have conceived already. Fertilization occurs when an egg and sperm connect and form a single cell, called a zygote.

Here’s what’s happening during your third week of pregnancy:

•  The microscopic-sized zygote divides again and again, growing at an astounding pace.
• Your baby already has all of the genetic material she needs for life -- half of the 23 pairs of chromosomes from you, and half from your partner.
• Your baby’s gender is already determined!

Tips for a Possible Mom-to-be

Learn what nutrients you need.

How well you eat and care for yourself makes a big difference in the quality of nutrition your baby receives.

What do the nutrients in your food and prenatal vitamins do?

• Calories provide energy to help your baby grow.
• Iron helps make the extra blood needed during pregnancy.
• Folic acid is critical during the first few weeks of pregnancy to ensure proper neurological development and to prevent neural tube defects.
• Protein helps produce blood and builds your baby’s tissues and muscles.
• Calcium and vitamin D work together to build your baby’s bones and teeth.