Labor is a three-stage process leading up to birth. The first stage begins when a pregnant woman's uterus contracts and her cervix dilates. The uterine contractions that occur with labor are caused by the hormones oxytocin and prostaglandin. During the second stage of labor, the baby is pushed through the vagina. The third stage of labor is the delivery of the placenta and fetal membranes, which happens just a few minutes after the baby is born. The length and experience of labor varies considerably among women.

Your doctor uses certain guidelines to determine if your labor is progressing normally. Occasionally, labor does not progress normally, and medical assistance or a cesarean section may be needed. If labor begins before the 37th week of pregnancy, it is considered preterm. If you have any symptoms of labor before the 37th week, you should call your doctor immediately.

There are many different aspects to labor. Here is some information on signs, stages, and what you can expect.

Your due date is only an estimate of when labor will begin. It is normal for labor to begin anytime within two weeks before or after your due date. Labor will begin with regular contractions of the uterus and the opening and thinning of the cervix. When your body is preparing for labor, you may experience the following signs:

Baby Dropping

It will feel as if your baby has dropped lower in your abdomen. This happens when your baby's head settles deeper into your pelvis. This occurs a few weeks to a few hours before labor begins.

Mucus Plug or "Show"

You may pass a thick plug of cervical mucus or have an increase of vaginal discharge that may look clear, slightly bloody, or pink. The mucus plug is pushed into the vagina when the cervix begins to open. This may occur several days before labor begins or during the onset of labor.

Water "Breaks"

You may feel a continuous trickle or a gush of fluid from your vagina. This is caused when the amniotic sac breaks, releasing the fluid that surrounded your baby during pregnancy. The water may break before labor starts, or it may not break until after labor has begun.

Regular Contractions

When regular contractions occur, you may actually be going into labor. Effective labor contractions (as opposed to false labor contractions) are usually felt in the abdomen, but with a heavy sense of low-back pressure or discomfort.

When you actually go into labor, you will experience the following signs:

  • Contractions that come at regular intervals and last about 30-40 seconds. The contractions will get closer and closer together.
  • Contractions that do not go away when you move around.
  • Pain from the contractions that may be felt in the back and the front of your abdomen.