After your partner ejaculates, millions of sperm will travel from the vagina to the fallopian tube where your egg is waiting. An enzyme is released that allows one sperm to penetrate the egg and fertilization then takes place.
During fertilization, the genetic material of the sperm and egg are combined. You are now pregnant - although your body is not yet letting you know that just yet. Fertilization has just occurred so by the end of this week, your baby’s sex will be determined. Depending on whether the father’s sex chromosome is an X or Y, your child will be a girl or a boy respectively.
During this week, the fertilized egg goes through a process of division from one cell to two cells to four cells and more. By the time it gets to the uterus, this group of cells numbers 32 and is called a morula. And at just one week after fertilization, there are already 250 cells! Read up on the fascinating suject of the reproductive process.
Your baby has not been conceived yet and you are still having your menstrual period. However, this week is still acknowledged as the first week of a forty-week pregnancy even though you’re not one week pregnant!
If you are trying to conceive, this is a perfect time to get your body ready for becoming pregnant. Remember to avoid alcohol, smoking and drugs as they can lead to birth defects as well as respiratory problems, low birth rate, fetal alcohol syndrome and other health problems.
What is considered to be your first week of pregnancy is actually your menstrual period. This week counts as part of your 40-week pregnancy even though your baby hasn’t been conceived yet. At this time you should take the time to prepare your body for motherhood. Before becoming pregnant, you should:
- Avoid alcohol, drugs, and tobacco products. These substances can cause birth defects, fetal alcohol syndrome, respiratory problems, low birth weight, and other health problems.
- Talk to your doctor about any prescription drugs you are taking. You’ll need to take special precautions with medication because many prescription and over-the-counter medications can adversely affect the fetus. However, you shouldn’t stop taking prescription drugs without consulting your health care provider - he or she will help you weigh potential benefits and risks to discontinuing your prescription.
- Maintain a diet that contains an adequate amount of vitamins, especially folic acid. Women who are attempting to become pregnant should take at least 0.4 to 0.8 milligrams of folic acid a day. Adequate folic acid intake reduces the risk of neural tube defects (birth defects caused by incomplete development of the brain or spinal cord), such as spina bifida. Be sure to talk to your health care provider about taking a folic acid supplement while you are trying to conceive.
Revision date: June 18, 2011
Last revised: by Janet A. Staessen, MD, PhD