A term pregnancy is defined as one in which birth occurs between 37 weeks and 42 weeks pregnant.
If birth occurs before the end of the 37th week of pregnancy, it is considered preterm. Babies who are born this early often have low birth weight — they weigh less than 5 1/2 pounds (2,500 grams) at birth. Their low weight, along with various other problems related to early birth, puts these infants at risk for numerous health problems.
The exact causes are unknown. Often it occurs in the absence of known risk factors. Still, factors that seem to increase a woman's risk of early labor have been identified.
Factors thatt increase the risk of preterm labor:
* Previous preterm birth
* Pregnancy with twins, triplets, or more
* More than one previous miscarriages or abortion
* Infection of the fetal membranes or the amniotic fluid
* Hydramnios (which is an excess of amniotic fluid)
* Problems with the placenta
* If the mother has a serious illness
The signs that labor is beginning too early in pregnancy may be subtle or severe. Preterm labor is usually, but not always, signaled by contractions of the uterus. If you notice more than five contractions during an hour, it is time to contact your doctor or your hospital. Contractions at first may consist of a tightening feeling in your abdomen, which you may be able to feel with your fingertips.
Uterine contractions may be accompanied by lower back pain and a feeling of heaviness in the lower pelvis and upper thighs.
Changes in vaginal discharge are also typical. There may be light spotting or bleeding along with the contractions. Or you may notice a watery fluid leaking from your vagina.
This may be amniotic fluid, a sign that the membranes surrounding the fetus have ruptured. If you pass the mucus plug — the mucus that accumulates in the cervix during pregnancy — you may notice this as a thick discharge tinged with blood.
For some women, the changes described above may occur without any sensation of uterine contractions. If you have doubts about what you're feeling — and especially if you have vaginal bleeding along with abdominal cramps or pain — call your doctor. Don't be embarrassed about mistaking false labor for the real thing.
If your doctor suspects that you maybe having early labor, you will need to be examined. Two of the first questions to be answered will be whether your cervix has begun to dilate and whether the fetal membranes have broken. A cervical examination will be necessary to answer these questions. A special monitor may be used to measure the length and spacing of your contractions.
With this information, your doctor will determine whether you are actually in labor.
When preterm labor is diagnosed, a decision must be made as to whether to try stopping labor or allow it to continue. Both your baby's and your own well-being must be weighed against the benefits and risks of delivery versus stopping labor.