It may surprise you to learn that when you find out you're pregnant, you're already at least one-third of the way through your first trimester of pregnancy. The first trimester is weeks 0-13.
Your Baby in the First Trimester of Pregnancy
The Mayo Clinic outlines much of what happens with your baby's development in the first trimester--most of it happening even before you realize you're pregnant. Your baby's heart starts beating by the twenty-fifth day, which means that your baby actually has blood moving through a basic circulatory system by 25 days after conception.
By your seventh week, your baby's sex glands are forming. They will be discernable by the beginning of your second trimester.
After eight weeks, your baby has simple kidneys, a liver, and a digestive tract. He is now moving his arms and legs and his brain is sending out simple impulses to organs. Your baby even has a basic spinal cord.
By the end of week twelve of your pregnancy, your baby has fingers and toes complete with fingernails and toenails. Your baby even has fingerprints! Via ultrasound, you may be able to see that your baby has ears, eyes, and a mouth. We can even see your baby practicing breathing movements. Your baby is not breathing air, but amniotic fluid.
By the end of the first trimester, your baby is three inches long and weighs about one ounce.
Your Body in the First Trimester
The first trimester of pregnancy is the worst for many women. Your body is going through a lot of hormonal changes and you may start experiencing pregnancy symptoms, although some women have a difficult time with pregnancy symptoms all the way through their pregnancy. Other women don't experience any symptoms at all. But, for most women, any symptoms will lift in the second trimester.
The pregnancy symptoms you might experience include nausea, vomiting, exhaustion, shortness of breath, more urination, dizziness, and moodiness. On the plus side, you don't even realize you're pregnant until week four or five -- when you're a third of way through your first trimester! As uncomfortable as you may be with your symptoms, some of which are outlined at the Mayo Clinic site, you don't need to worry that they are hurting your baby.
Unless you're pregnant with multiples, you probably won't notice much of change in your body. At the end of the first trimester, you might have a little bit of a belly and slightly larger breasts.
Things to do in the First Trimester
- Because of the risk of miscarriage, you may not want to tell the world you're pregnant yet, though that decision is up to you and your partner.
- You should be looking into choosing a care provider for your pregnancy and birth. You can hire a midwife or ob-gyn.
- At this point, though your body is going through many changes, you probably won't need to buy maternity clothing. However, it may not hurt to decide how much you want to spend on new clothing.
- If you and your partner are working, you will want to check with your HR departments to learn about maternity/paternity leave or how much paid time you can take off work and how much unpaid time you can take off work. You should also check to see if your health care benefits will change after the baby is born.
- You will want to increase your calorie intake slightly, but most medical professionals, as well as guidelines offered by Mayo Clinic, will remind you that you're not eating for two. You should try to cut back on junk food, fast food, and sugary foods while replacing these calories with fruits and vegetables. You should be avoiding cigarettes, alcohol, and recreational drugs. If you're having problems quitting alcohol or recreational drugs, you should talk to your care provider as soon as you can.
- You may want to take a prenatal vitamin. Some women feel the pills make their morning sickness worse, but prenatal vitamins are still important in the first trimester.
- If you were exercising before you got pregnant, you can still continue your regimen for as long as you feel comfortable. However, you should watch for overheating and dehydration.
Just the Beginning
The first trimester of pregnancy can be difficult as you adjust to your pregnancy. Not only is your body making some major changes, but your baby is going through amazing growth and development. Remember that by the second trimester you will probably feel better and have more energy.