Physiological Labor


The process of childbirth, for all practical purposes, starts weeks before you feel your first contraction. Your body will be preparing for the upcoming event in several ways you may or may not notice. Even if you do not recognize these events, they are happening. Although these events may alert you that your labor will be starting soon, the definition of soon can be anywhere from a few hours to a few weeks. There is no time-table your body has to follow.

The first of these events may be an increase of circulating blood volume, which can be recognized by mild or moderate swelling. Your body is designed to prepare for the blood loss after birth by providing you with more blood before labor begins. Because the blood must be held somewhere, the body will increase the capacity of the circulatory system by swelling tissues.

Another event you may notice is the increase of irregular rhythmic contractions known as Braxton-Hicks. These contractions are important for preparing your uterine muscle for the upcoming labor and birth. Muscle is strengthened by use, and these irregular contractions are effectively bicep curls for your uterus. Although some women are troubled by Braxton-Hicks contractions, most find them painless.

Sometimes the Braxton-Hicks come at regular intervals for a few hours. That is ok. In the past this was called false labor, but that term is misleading because although it will not end with your baby in your arms, your body is doing real work during this time. A better term is pre-labor, which refers to the work your body does to prepare for labor. You will know when it becomes real labor because the contractions will be less than 10 minutes apart, getting progressively closer together and progressively stronger. If you are unsure, change your activity or eat to see if that has an effect on the contractions. If by changing your activity level or eating a small snack you find your contractions slow down or spread out, you will know that this is pre-labor.

You may also notice that your breasts begin to secrete a thick yellow fluid known as colostrum. This will be your baby's first food. Although it is low in calories compared to mature milk, it is packed with value. Colostrum has a very high concentration of protein and antibodies from your immune system, which protect your baby from illness for the first few days. It also acts as a laxative to help move the meconium out of your baby's digestive system. High levels of some vitamins and minerals may further protect your baby and may be important in the continued development of the heart, brain and central nervous system.

Some women recognize when they have lost their mucus plug, others have no idea when or if it happened. The mucus plug is a grey "blob" of mucus (similar in texture to nasal mucus) that closes your cervix to protect the uterus during pregnancy. Seeing the plug in the toilet or in your underwear is an indication that your cervix has begun to dilate. But don't rush to your doctor yet. You could lose your mucus plug and still have a few weeks to wait for labor to begin.

Another signal of impending labor is what is termed "bloody show." This is blood-tinged mucus from your cervix as it thins and dilates. You may find it in the toilet or in your underwear. Do not be concerned abut confusing this with vaginal bleeding which may indicate there is a problem. In general, the bloody show is a small amount of bright red blood and may contain a few small clumps.

You may begin to notice that over the last few hours your Braxton-Hicks contractions are getting closer together and lasting a little longer. You may also find that your body is clearing itself with a mild diarrhea. These should be indications to you that you are probably moving into true labor, but again, only time will tell. It can be very normal to start early labor, have it stop, and then have it start again in about 48 hours.

Ideally, your contractions will get progressively longer, stronger and closer together. These contractions will help align the baby properly and push the baby and the bag of waters against the cervix to stretch it around the baby's head. Your caregiver may be interested in the progress of this cervical dilation, but history has shown it is not very reliable for determining how long you will be in labor. Women have a habit of achieving several centimeters of dilation over very few contractions, and then waiting a few hours for the next change of dilation.

At home, as your contractions get progressively stronger and longer you may begin to wonder just where you are in labor and how much longer you have to go. No one can say for sure, but there are some clues you can use to make educated guesses. For example, if your contractions started at less than eight minutes apart, you might expect your labor will be shorter than the average (but remember the average is 15 hours, and shorter may mean 12 or 13 hours, or it could mean 4 or 5 hours). If your contracts started at 12 minutes apart or more, you may want to plan that your labor will be longer than average.