What are the Stages of Pregnancy?
The stages of pregnancy are typically divided into three stages, or trimesters, based on the gestational age of your unborn child. Since the exact date of conception is seldom known, the gestational age is usually calculated from the date of your last period. Forty weeks after the first day of your last menstrual period is the initial estimated due date, but this is just an estimate since most babies are born between 38-42 weeks from the first day of your last menstrual period. For more information visit estimating due date on the website PregnancyAndChildren.com.
The first stage, or first trimester, is based on the baby's gestational age from weeks 0-12; the 2nd trimester is from weeks 13-26; and the 3rd trimester is from week 27 until the end of the pregnancy (approximately 40 weeks). Sometimes a pregnancy calendar is used to track the changes taking place in you and the baby. Below, we provide a rough guide of what to expect in each of the stages of pregnancy.
What is the First Stage of Pregnancy?
During the first stage of pregnancy, the first 3 months or the first trimester, your body undergoes many changes and you can experience a variety of pregnancy symptoms. As your body adjusts to the growing baby, you may experience many of the early symptoms of pregnancy including nausea, vomiting, mood swings, irritability, swollen and tender breasts, unusual responses to food, weight gain, and the need to urinate frequently. Many women find they are very easily fatigued and exhausted in this first stage of pregnancy. Some of these discomforts will go away as your pregnancy progresses and a few women might not feel any discomfort at all. If you have been pregnant before, you might feel differently during this pregnancy. Just as each woman is different, so is each pregnancy.
By the end of the 1st trimester, your baby is about 3 inches long and weighs less than an ounce. The eyes move closer together into their positions and the ears also are in position. The liver is making bile, and the kidneys are secreting urine into the bladder.
What is the Second Stage of Pregnancy?
Most women find the second stage of pregnancy easier than the first. You may find that morning sickness and fatigue are going away, but other changes to your body are now occurring. Your abdomen will expand as you gain weight as the baby continues to grow. Before this trimester is over, you probably will feel your baby beginning to move. Some of the following changes may make their first appearance during the second trimester.
It is normal to gain about one pound per week, or about 3-4 pounds per month during this 2nd stage of pregnancy (from 4-6 months or 13-26 weeks). Many of the aches and pains you had in the 1st trimester may continue and you are likely to have pain in your abdomen, groin, and thighs, experience backaches, shortness of breath, skin changes, and itching on your abdomen, palms, and soles of the feet.
By the end of this 2nd stage of pregnancy your baby will weigh about 1 1/2 to 2 pounds and be about 12-14 inches long. With this growth comes the development of fingers, toes, eyelashes, and eyebrows and by the end of the 26th week your baby's essential organs like the heart, lungs, and kidneys are formed.
What is the Third Stage of Pregnancy?
Many of the symptoms you had in your 2nd stage of pregnancy will continue into this 3rd stage (from 7-9 months or 27-40 weeks). Since the baby has continued to grow, you will continue to gain weight. While everyone gains weight at different rates, on average it is normal to gain about one pound per week, or 3-4 pounds per month, during the 3rd trimester. By the end of your pregnancy you should have gained, on average, about 25 to 35 pounds of which approximately 7-8 pounds of that weight will be the baby. Due to the weight gain and growth of the baby, you may find it more difficult to breathe and you may become fatigued much more easily. You may develop heartburn, become constipated, have trouble sleeping, and may experience swelling of your breasts, ankles, fingers, and face.
Your baby is still growing and moving and all of the baby's limbs and organs are maturing and getting ready for birth. Even before your baby is born he/she will be able to open and close their eyes and might even suck their thumb. As your body prepares for birth, the baby will start to move into a normal position for a vaginal birth. You might notice the baby "dropping," or moving down lower in your abdomen.
Where Can I Find Additional Sources of Information?
Do not ignore the early symptoms of pregnancy by just wishing or hoping that they will go away. You should contact your health care provider or take a home pregnancy test. If you have these symptoms and are not pregnant, you should contact your health care provider to find the cause of the problem. If you are pregnant, it is important for you and your baby to start prenatal care as soon as possible. Your health provider can also help you to develop a realistic birth plan so that your pregnancy, labor and delivery, and the after-birth care of you and your baby can proceed as you wish. For additional information on pregnancy, labor, delivery, and a whole range of pregnancy related issues visit the National Women's Health Information Center.