There are various stages of pregnancy, usually referred to as trimesters. The changes in the fetus, and the mother can basically be broken up into these three stages. Let's take a look at the various stages of pregnancy, and what those mean for mom and baby:

First Trimester

The first trimester is the first 12 weeks, or 3 months of pregnancy. This is when your body starts to really change, it experiences things like increased blood volume, extra hormones, and more. So, typically, a mother's body has to adjust to this baby growing inside her, and thus experiences nausea, fatigue, backaches, mood swings, stress, etc. as the body gears up to have a baby. Each pregnancy and each person is going to be different, so even if you experienced one set of discomforts during a previous pregnancy does not mean you will experience them in the next.

During the first trimester, you will likely want to take some common tests. These tests usually indicate if your fetus is at risk for birth defects. It is not for determining what defects they have, just if they are at risk. The following are some of the tests that if taken should be done in the first trimester:

Nuchal translucency screening (NTS): This is a test that measures risk of some specific birth defects. It is administered with an ultrasound and blood test. The doctor checks the thickness of the back of the fetus' neck, and tests the blood for levels of a protein called pregnancy-associated plasma protein and a hormone called human chorionic gonadotropin (hCG). It is performed at 11 weeks typically.

Chorionic villus sampling (CVS): CVS is performed between 10 and 12 weeks of pregnancy. If you opt for this test your doctor will use a hollow needle, inserted through the abdomen to take a sample of the placenta. It is then tested to see if your baby has neural tube disorders.

Because the first stage of pregnancy means a lot of internal body changes, it can be difficult to deal with. The following are some tips for dealing with the first stage of pregnancy:

Tiredness: Because your body is working to get ready to grow this baby, you can be too tired. To fight this, get some sleep, try for eight hours, and get naps in if you need it. Also, sleep on your left side in order to relieve pressure on major blood vessels that supply oxygen and nutrients to the fetus. It is also smart to not get stressed as it can add to fatigue.

Nausea and Vomiting: This is called "morning sickness," but it can occur anytime. It usually goes away after this first stage of pregnancy. To help soothe nausea so you vomit less, eat frequent, small meals; avoid fatty and spicy foods as they are harder for the digestive tract; eat starchy foods, especially when nauseated; avoid fluids at meals; eat before you get out of bed.

Frequency of Urination: During early pregnancy your uterus grows, and this puts pressure on the bladder, which causes more frequent urination. The only thing you can do is go when you feel the need, and try to drink less at night so you can sleep without interruption.

Weight gain: This is usually not an issue for women during the first trimester. You will probably only gain a pound a month.

So you feel awful, but what is going on with your baby? Basically, your baby is still like a "gummy bear" it is only about three inches long and weighs about half an ounce. At this point the eyes are in position, and their ears are also in position. At this point the liver is making bile, and kidneys secrete urine. The baby is also able to move, but you won't be feeling it yet.

What role does your doctor play during this stage of pregnancy? Well, basically your doctor is going to ensure you are healthy, that you or your family do not have a history that indicates potential problems for the fetus, they do lab tests and a pelvic exam. They will also watch your weight gain and blood pressure during this stage. They also use this stage to determine your due date.

Second Trimester

The second trimester is from week 13-24. This is considered the easiest of the trimesters, or at least the least uncomfortable. However, despite the fact that it is less uncomfortable, it is still important that you see your doctor.

Typically the nausea and vomiting go away, but there are still going to be changes in your body. For example, your breasts get larger, your back might start to hurt, you might get hemorrhoids, spider veins, etc. This is the stage when your abdomen starts to expand, and you actually start gaining weight. Before the second trimester ends you should be able to feel the baby move.

The second trimester is when a lot of tests are performed, most of which are optional. The following are some of the common tests taken during the second trimester.

Ultrasound: This is not a test, but during the ultrasound your doctor will check to see if your baby is developing properly, and can determine the baby's sex as well. Most major problems with the way your baby is formed can be seen at this time. Your doctor can also use the ultrasound to see if your baby has any neural tube defects.

Amniocentesis: This test is performed no sooner than 16 weeks. Your doctor will use a needle to get a sample of amniotic fluid from the amniotic sac for testing. The fluid is tested for AFP, and other birth defects.

Chorionic villus sampling (CVS): Explained above, usually performed in first trimester, but can be done at start of second trimester.

Maternal serum screening test: This is a blood test. It is usually given between weeks 15 and 20. It checks for birth defects such as Down syndrome, trisomy 18, or open neural tube defects. It tests for 3 chemicals: alpha-fetoprotein (AFP), and two pregnancy hormones: estriol and human chorionic gonadotropin (hCG). Sometimes, doctors test for inhibin-A.

Because many of the aches and pains you had in the first trimester continue, but there are also some new ones, let's look at some of the things you can do ease the pain.

Backaches: You have excess weight, so other than supporting your back when you sit and sleep there is not a lot you can do.

Shortness of breath: Your body has to process excess oxygen for the placenta, and this can lead to shortness of breath. Just do not overeat, etc. or there might be less room for your to breathe as well.

Stretch Marks: The skin is stretching, so the best thing you can do is get plenty of fluid so that the skin elasticity is good, and you can reduce the chances of stretch marks.

Weight Gain: Everyone gains weight at different rates. On average, it is normal to gain about one pound per week, or about three to four pounds per month during this trimester.

Itchiness: the skin itches, and the fact is that the best way you can help it is to use moisturizer.

So, what is going on with baby during this stage? Well, at this point your baby will weigh close to two pounds and be 13 inches long or so. It will now have fingers, toes, eyelashes, eyebrows, etc. You will start feeling the baby move at week 20 or so. Near the end of this pregnancy stage your baby's organs like their heart and lungs are formed.

During your doctor visits you will most likely have routine tests such as urine tests and blood pressure. You will be weighed, and your doctor will measure your stomach to ensure your baby is growing properly. The doctor will also listen for the heartbeat each visit to check that the baby is growing properly.

Third Trimester

This is one of the most difficult trimesters as your weight is far heavier, and you get all the same symptoms you had before and more. Breathing becomes more difficult, and you once again have to urinate a lot. You may also start to experience heartburn, constipation, etc. This is because the baby is getting bigger and it is putting more pressure on your organs, but don't worry, you will be fine.

Usually the only test you have during the third trimester is a glucose screening test, and a strep B test.

To help make the third trimester lass uncomfortable, try the following:

Trouble sleeping: Sleeping in the third trimester can be very difficult, you have less energy, and because you are big it is hard to get comfortable, plus you have to go to the bathroom a lot, and your body's metabolism goes up making it harder to sleep. To make sleep easier, do not eat too large of meals, exercise during the day (though not too intensely), try not to nap much during the day, do things to relieve stress, and stick with a schedule.

Heartburn: if you want to avoid it, eat smaller meals and enjoy anti-acids if your suffering gets too intense.
 
Swelling: The uterus puts pressure on veins that return blood from the ankles and feet, but you can reduce it by drinking plenty of water, and by elevating your feet during the day.

Hemorrhoids: get a butt pillow, and if you can take it, massage the hemorrhoids while you take a warm shower.

Tender breasts: Wear a supportive bra, and take your boobs off limits for a while.

Weight gain: Everyone gains weight at different rates, but by the end of the pregnancy you should have gained 25-35 pounds.

Your body has changed, what about your baby? Basically, your baby is still growing and moving, but it has less room now, so you feel it more. Your baby is going to finish development of all organs, and body parts during this trimester. It will be able to suck its thumb, and close its eyes. It will start to get in the birth position during this trimester.

Doctors visits will not change much from the second trimester except that you go more often, and in the last 8-10 weeks your doctor will start to watch for signs of labor. Your doctor will also check you to see if your cervix has started to dilate and efface in preparation for labor.