Your Pregnancy - A Week by Week Look

Pregnancy can be the best time in a woman's life. The first time you are pregnant can prove to be a scary time. The fear of the unknown may take over. A lot is happening during the typical 40 weeks gestation for not only the baby, but also the mother. Here is a guide of some of the things that happen during pregnancy as well as a time line of some other important things, such as tests that may be done.

Weeks 1-3

Some signs and symptoms of pregnancy can include: missed menstrual period, nausea, vomiting, fatigue, urinating more often and breast changes.
At this point, you will not have any signs or symptoms since it fertilization just occurred. The embryo is very small at this point, only the size of a pin's head. The group of cells that make up the embryo are constantly multiplying and growing.

Week 4

The still developing baby is very small. It can be about 0.014 inch to about 0.04 inch in length. This is the time you would be expecting your period so now is when the possibility of being pregnant may enter your mind for the first time.

Week 5

The baby is now about 0.05 inch long. There are no big noticeable changes in you at this point except for the fact that your period is late and you either suspect that you are pregnant or you just found out. You may go to the doctor at this point to have a blood test done to confirm pregnancy. This test is called HCG, or human chorionic gonadotripin. This test will detect the presence of the hormone HCG which is present during pregnancy. You could begin to have morning sickness at this point. Nausea and/or vomiting may start now. Morning sickness usually ends by the end of the first trimester. Some women experience morning sickness to some degree for more than just the first trimester. Your breasts may be sore now and the frequent urination may have also started. This is a good time to call your ob/gyn and schedule that first prenatal appointment.

Week 6

The crown to rump length of the baby is about 0.08 to 0.16 inch. This is how they measure the baby, crown to rump. It is the height or distance from the top of the baby's head to its buttocks. If an ultrasound is done, a heartbeat can be detected at this point. Some women start to gain weight now and some lose some weight. On pelvic exam, the physician can tell that you are indeed pregnant by the size and changes in your cervix and uterus. This is the beginning of the embryonic stage which lasts to 10 weeks gestation. This is an important time in the developing baby. Most malformations happen during this time. The heart tubes fuse and the heart begins to contract. Limb buds are seen now and the early brain chambers are forming. You may have some food cravings start now as well as constipation and heartburn, which can continue throughout your pregnancy.

Weeks 7-8

The crown to rump length is about 0.16 to 0.2 inch. This is the size of a BB pellet. During this week, there is a definitive growth spurt. You are still not showing yet and yet you may be feeling pregnant at this point. This is a good time to make sure that you are eating properly and taking your prenatal vitamin. Prenatal vitamins should be started before trying to conceive if possible. If not, at least when you first suspect or find out that you are pregnant. Eating a nutritional diet and exercising are both good ways to help the developing baby to be a healthy one. You should increase your caloric intake by about 500 extra calories a day while pregnant. The crown to rump length is about 0.56 to 0.8 inch at 8 weeks. This is the size of a larger bean. You will probably have your first prenatal check up around week 8. You will have an array of blood tests done as well as a pelvic exam. Some doctors order an ultrasound just to make sure that all is going according to schedule.

Weeks 9-12

At week 9, the crown to rump length is about 0.9 to 1.2 inches. By week 12, it is about 2.5 inches. The baby weighs about 0.5 ounces at 12 weeks. At the end of week 10, the embryonic period is ending. The fetal period is beginning. By the end of week 10, development of organ systems and the body are well under way. The baby is now beginning to look more human. Your doctor may offer you a test called a chorionic villus sampling, or CVS, if you have certain risk factors. This test is used to detect genetic abnormalities. It is similar to an amniocentesis. A CVS is done between weeks 9 and 11. It can detect genetic defects, such as Down syndrome. This test is done earlier than an amniocentesis so if termination is desired, it is still done at this point. CVS is done by removing fetal tissue from the placenta. The risk of miscarriage is between 1 and 2%. Many doctors do an ultrasound around week 12 if one wasn't done earlier. This will detect fetal movement as well as a heartbeat. This ultrasound can detect if there are more than one baby in the uterus as well. Some fetal abnormalities can be detected by ultrasound at this point. Location of the placenta will also be seen. Around your 12th week visit, you will be able to hear the heartbeat with a fetal doppler. There are many companies out there that even allow you to rent a doppler for the duration of your pregnancy for a small fee so that you can hear the baby's heartbeat whenever you like. You may begin to show a little now.

Weeks 13-16

The crown to rump length at week 13 is about 2.6 to 3.1 inches and by week 16, it is around 4.6 inches long. Your clothes may be a little tight around now and you are probably showing by this point. Now the world will know that you are expecting. Around week 15, your doctor will offer you a blood test called an alpha-fetoprotein test, or AFP, which is a test to determine if you might be having a child with Down syndrome. If the test comes back abnormal, your doctor may suggest an amniocentesis to be sure. The risk of Down syndrome is about 1 in 964 births for a 30 year old and 1 in 109 births in a 40 year old. By the age of 49, the risk is about 1 in every 12 births. Family history is also taken into consideration. Around week 16, an amniocentesis can be done. This is another genetic test. This is done by inserting a long needle in to the abdomen to collect a sample of amniotic fluid. An ultrasound is done to guide the needle in so that it doesn't touch the baby. If the mother is RH negative, which is something they should have tested you for in that first series of blood tests, you will need a Rhogam shot around week 28 but you will also need one if you have an amniocentesis done. You will also have a Rhogam shot when the baby delivers and if you miscarriage.

Weeks 17-20

At week 17, the crown to rump length is about 4.8 inches and by week 20 it is about 6.4 inches. By week 20, your baby weighs about 9 ounces. You are probably showing now and the world knows you are expecting a little bundle of joy. You will start to feel that little bundle moving somewhere around 17-20 weeks for your first pregnancy and a little earlier with subsequent pregnancies. Your back may start hurting now and if you had morning sickness, that should be a thing of the past. You may experience nasal symptoms during pregnancy. They will go away when the baby is born, if not sooner. Some things to keep in mind are some warning signs that require a doctors visit. Any vaginal bleeding, severe swelling of the face, severe pain, gush of fluid from the vagina, lack of movement in the fetus, blurring of your vision, severe vomiting, a severe headache and any injury or accident should be checked out by your doctor immediately. Around weeks 18-20, an ultrasound is done and this is the ultrasound that can detect the sex of the baby. How exciting!!!

Weeks 21-28

By week 28, the crown to rump length is about 10-11 inches and the baby weighs about 2.4 pounds. Hemorrhoids may hit you at this point. Some women never experience them at all. Around week 24, your doctor will check you for gestational diabetes. Gestational diabetes affects about 10% of all pregnant women. Once pregnancy is over, it goes away. It does, however, increase your chances of having it in subsequent pregnancies as well as becoming diabetic in later years.

Weeks 29-36

At week 29, the crown to rump length is about 10.4 inches and the baby weighs about 2.7 pounds. By week 36, the crown to rump length is about 13-14 inches and the baby weighs about 6 pounds. What a big increase in the past 7 to 8 weeks!!! During this period of your pregnancy, your doctor may do a non stress test, or NST to check how your baby relates to contraction. The monitor is strapped to your belly and it watches how your baby's heart rate reacts to contractions. A BPP,biophysical profile, may also be done. This is an ultrasound that gives you a score based on a few things. It evaluates fetal breathing, fetal body movements, fetal tone, the amount of amniotic fluid and the reactive fetal heart rate.

Week 37-40

You can give birth at any time during these last few weeks. Week 37 is considered to be full term. Labor can begin at any time now. By this point, almost all pregnant women are ready to meet their baby and face labor and delivey with a smile. Some women deliver after week 40 so don't be surprised if your due date comes and goes. This is very common among first time moms. You many lose your mucous plug sometime around this point. This is a ball of blood tinged mucous that occurs as the cervix begins to dilate. This means that labor is beginning. You can go into active labor within hours of losing your mucous plug or days. Any day now, you will be a mother!!!

Labor and delivery is the big finale to your 40 weeks or so of pregnancy. The moment you see the baby for the first time will make the whole pregnancy experience, no matter how bad it was, seem like it was worth wild. Many women can't wait to do it again too!! Enjoy your baby as time goes too fast!!!