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Next Chapter: How the Uterus Contracts
Starting labor is a little like starting your car on a cold January morning; sometimes it takes a few tries before it "turns over." A few women start true labor abruptly, but many experience one or two episodes of false labor before the real thing begins. Since that's the case, you might worry about whether you are really in labor. There is no reason to worry, though, because nobody ever missed her own labor. If you are not sure you're in labor, you probably aren't. And even if you are, you'll most likely have plenty of time to get to the hospital.
How can you tell the difference between false labor and true labor? In true labor, you will feel regular uterine contractions, every 5 minutes or even more frequently. Each contraction will last at least 45 seconds. These regular contractions must continue for at least an hour before you should consider it to be labor; even then, you may be wrong. In true labor, the contractions become increasingly longer, stronger, and more frequent. In response to these contractions, the cervix thins out and begins to dilate (open).
Many women who have already delivered one baby find that their next labor is considerably shorter; it's like getting extra credit for having been through it once before. These women are advised to call their doctor when they have had regular contractions for an hour-even if the contractions are further apart than every five minutes.
The average first labor lasts for 12-18 hours before the cervix dilates to 10 cm., and it usually takes an additional 1-2 hours to push the baby out. Therefore, not much is likely to happen in the first hour. In false labor, the contractions weaken or occur less frequently. In this case, the contractions will eventually stop, only to start again hours (or even days) later.
Progress is usually very slow during the early phase of labor, which is also called the latent phase. Many contractions and a lot of time are required to make the cervix dilate the first few centimeters. However, each subsequent centimeter of dilatation takes less time to occur than the previous dilations. Stronger contractions facilitate increased dilation as they intensify during the course of labor.
You probably will be relatively comfortable during the early part of the latent phase of labor. Walking around is strongly encouraged, because it naturally stimulates labor. As the hours pass, though, you may become frustrated by the slow progress and the increasing discomfort. You may become so tired and fed up to the point where that pain medication seems very appealing. Unfortunately, pain medication or an epidural given in the latent phase is likely to slow down your labor, possibly so much so that medical intervention (such as administering Pitocin to induce labor) may be required to get it back on track again. (For more on epidural anesthesia, see Chapter 24.) This is why it's important to try to hang on until the active phase of labor begins. At that point, pain medication or an epidural cannot slow down or stop your labor.