Recognizing Premature Labor

What is Premature Labor?

A term pregnancy takes about 40 weeks to complete. Babies born before 37 weeks may have problems breathing, eating and keeping warm. Premature labor occurs between the 20th and 37th week of pregnancy, when uterine contractions cause the cervix, the mouth of the uterus or womb, to open earlier than normal. This can result in premature birth.

Certain factors may increase a woman's chances of having premature labor, such as carrying twins. However, the specific cause or causes of premature labor are not known. Sometimes a woman may have premature labor for no apparent reason.

Warning Signs of Premature Labor

It may be possible to prevent a premature birth by knowing the warning signs of premature labor and by seeking care early if these signs occur. Warning signs and symptoms for premature labor include:

  • Uterine contractions that happen six or more times in an hour, with or without any other warning signs.
  • Menstrual-like cramps felt in the lower abdomen that may come and go or be constant.
  • Low dull backache felt below the waistline that may come and go or be constant.
  • Pelvic pressure that feels like your baby is pushing down. This pressure comes and goes.
  • Abdominal cramping with or without diarrhea.
  • Increase or change in vaginal discharge such as change into a mucousy, watery or bloody discharge.

Uterine Contractions: How to Tell What's Normal

It is normal to have some uterine contractions throughout the day. They often occur when you change positions, such as from sitting to lying down. It is not normal to have frequent uterine contractions, such as six or more in one hour. Frequent uterine contractions or tightenings may cause your cervix to begin to open.

Since the onset of premature labor is very subtle and often hard to recognize, it is important to know how to feel your abdomen for uterine contractions. You can feel for contractions in this way:

  • While lying down, place your fingertips on the top of your uterus
  • A contraction is a periodic tightening or hardening of your uterus. If your uterus is contracting, you will actually feel your abdomen get tight or hard, and then feel it relax or soften when the contraction is over.

What To Do If You Think You May Have Symptoms of Premature Labor

If you think you are having uterine contractions or any other signs and symptoms of premature labor:

  1. Lie down tilted towards your side. Place a pillow at your back for support.
    • Sometimes lying down for an hour may slow down or stop the signs and symptoms.
    • Do not lie flat on your back, because lying flat may cause the contractions to occur more often.
    • Do not turn completely on your side, because you may not be able to feel the contractions.
    • Hydrate yourself by drinking several large glasses of water. Sometimes being dehydrated can cause contractions.
  2. Check for contractions for one hour.
    • To tell how often contractions are occurring, check the minutes that elapse from the beginning of one contraction to the beginning of the next.
  3. Call your provider or the UCSF Birth Center at (415) 353-1787 or go to the hospital if you experience any of the following:
    • You have six or more uterine contractions in one hour
    • You have any of the other signs and symptoms for one hour
    • You have any spotting or leaking of fluid from your vagina

With acknowledgement to Dr. Robert K. Creasy for his assistance and to the March of Dimes Birth Defects Foundation for their support.


Reviewed by health care specialists at UCSF Medical Center.

This information is for educational purposes only and is not intended to replace the advice of your doctor or health care provider. We encourage you to discuss with your doctor any questions or concerns you may have.