Pregnancy definition and facts

A normal pregnancy lasts about 40 weeks and is grouped into three stages, or trimesters.

Symptoms and early signs of pregnancy include

the absence of menstrual periods,

breast changes,

tiredness,

nausea,

mood swings, or

other symptoms.

A pregnancy test measures the level of hormone human chorionic gonadotropin (HCG) in the urine or blood. The test may be positive before the first signs of pregnancy develop in some women.

Symptoms of late pregnancy can include

heartburn,

difficulty sleeping,

swelling of the ankles or fingers,

hemorrhoids, and

mild contractions.

Many of these symptoms result from the weight gain and enlarging uterus in late pregnancy.

By the end of 37 weeks, a baby is considered full term and its organs are ready to function on their own.

As you near your due date, your baby may turn into a head-down position for birth. Most babies "present" head down.

Babies at birth typically weigh between 6 pounds 2 ounces and 9 pounds 2 ounces and are 19 to 21 inches long. Most full-term babies fall within these ranges.

How many weeks is a normal term pregnancy?

Pregnancy lasts about 40 weeks, counting from the first day of your last normal period. The weeks are grouped into three trimesters (TREYE-mess-turs). Find out what's happening with you and your baby in these three stages.

What is the first trimester of pregnancy (week 1-week 12)?

During the first trimester your body undergoes many changes. Hormonal changes affect almost every organ system in your body. These changes can trigger symptoms even in the very first weeks of pregnancy. Your period stopping is a clear sign that you are pregnant. Other changes may include:

Extreme tiredness

Tender, swollen breasts. Your nipples might also stick out.

Upset stomach with or without throwing up (morning sickness)

Cravings or distaste for certain foods

Mood swings

Constipation (trouble having bowel movements)

Need to pass urine more often

Headache

Heartburn

Weight gain or loss

As your body changes, you might need to make changes to your daily routine, such as going to bed earlier or eating frequent, small meals. Fortunately, most of these discomforts will go away as your pregnancy progresses. And some women might not feel any discomfort at all! If you have been pregnant before, you might feel differently this time around. Just as each woman is different, so is each pregnancy.

What is the second trimester of pregnancy (week 13-week 28)?

Most women find the second trimester of pregnancy easier than the first. But it is just as important to stay informed about your pregnancy during these months.

You might notice that symptoms like nausea and fatigue are going away. But other new, more noticeable changes to your body are now happening. Your abdomen will expand as the baby continues to grow. And before this trimester is over, you will feel your baby beginning to move!

As your body changes to make room for your growing baby, you may have:

Body aches, such as back, abdomen, groin, or thigh pain

Stretch marks on your abdomen, breasts, thighs, or buttocks

Darkening of the skin around your nipples

A line on the skin running from belly button to pubic hairline

Patches of darker skin, usually over the cheeks, forehead, nose, or upper lip. Patches often match on both sides of the face. This is sometimes called the mask of pregnancy

Numb or tingling hands, called carpal tunnel syndrome

Itching on the abdomen, palms, and soles of the feet. (Call your doctor if you have nausea, loss of appetite, vomiting, jaundice or fatigue combined with itching. These can be signs of a serious liver problem.)

Swelling of the ankles, fingers, and face. (If you notice any sudden or extreme swelling or if you gain a lot of weight really quickly, call your doctor right away. This could be a sign of preeclampsia.)

What is the third trimester trimester of pregnancy (week 29-week 40)?

You're in the home stretch! Some of the same discomforts you had in your second trimester will continue. Plus, many women find breathing difficult and notice they have to go to the bathroom even more often. This is because the baby is getting bigger and it is putting more pressure on your organs. Don't worry, your baby is fine and these problems will lessen once you give birth.

Some new body changes you might notice in the third trimester include:

Shortness of breath

Heartburn

Swelling of the ankles, fingers, and face. (If you notice any sudden or extreme swelling or if you gain a lot of weight really quickly, call your doctor right away. This could be a sign of preeclampsia.)

Hemorrhoids

Tender breasts, which may leak a watery pre-milk called colostrum (kuh-LOSS-struhm)

Your belly button may stick out

Trouble sleeping

The baby "dropping," or moving lower in your abdomen

Contractions, which can be a sign of real or false labor

As you near your due date, your cervix becomes thinner and softer (called effacing). This is a normal, natural process that helps the birth canal to open during the birthing process. Your doctor will check your progress with a vaginal exam as you near your due date. Get excited - the final countdown has begun!