Doctor's Notes on Pregnancy Labor Signs and Symptoms
Labor, used as a medical term, means the process of childbirth, from the start of regular uterine contractions to delivery. Labor is a sign and symptom of delivery. Some physicians include lightening, which involves the baby dropping down into the pelvis (short of breath, feel heavy or pressure, increased urination) that occur before normal uterine contractions begin. Bloody show, a brownish vaginal discharge and/or blood tinged mucus plug, may be discharged along with irregular false labor pains can occur before labor and “water breaks” refers to the leaking or disruption of amniotic membranes causing fluid to leak from the vagina, usually a sign that labor time is near. Some consider these as pre-labor signs. Signs and symptoms of labor are dilation of the cervix opening and increasing shortening of times between painful uterine contractions that continue until the baby is expelled from the vagina (delivery).
The exact cause or trigger of labor is not exactly known; however, researchers consider that hormone changes in the baby and the mother likely interact to trigger labor. For example, oxytocin from the fetus and mother may stimulate the uterus to contract and trigger prostaglandins which, in turn, open the cervix and also facilitate uterine contractions.
Pregnancy Labor Signs and Symptoms Symptoms
- Also referred to as the baby "dropping", the term "lightening" refers to the descent of the baby downward into the pelvis.
- Often, women experience less shortness of breath, as the diaphragm extends downward and the lungs have more room to expand.
- A feeling of heaviness or pressure may be felt in the pelvis, and the frequency of urination may increase.
- With the first term pregnancy, lightening usually occurs several weeks prior to the onset of labor.
- As the cervix thins and begins to dilate in preparation for delivery, small capillaries burst and cause a pink or brown vaginal discharge. The cervix begins to soften in anticipation of labor ("ripening").
- Cervical mucus, produced by glands lining the cervix, is expressed as the descending fetal head exerts pressure on the cervix. Blood-tinged mucus (i.e. the "mucus plug" or "bloody show") may be discharged from the vagina due to pressure from the fetal head on the cervical glands.
- Bloody show can occur anywhere from hours to several weeks prior to the onset of labor.
- If bleeding from the vagina is profuse, there may be a problem with the placenta, and the provider of obstetrical care should be notified immediately.
- Some women notice a burst of energy a few days prior to going into labor.
Nausea and diarrhea
Braxton Hicks contractions
- Several weeks prior to the onset of actual labor, the woman may develop irregular contractions of mild intensity. They tend to increase in strength and frequency as the onset true labor approaches.
- Braxton-Hicks contractions are also called "false labor pains," as they do not cause any change in cervical dilatation or effacement (i.e. thinning).
Rupture of the membranes ("water breaks")
- Rupture of the membranes refers to disruption of the amniotic sac that surrounds the baby, usually resulting in leakage of the amniotic fluid from the vagina. This fluid may be expelled as a sudden gush or as a slow trickle. Although most women will be contracting when the membranes rupture, in some cases it may occur prior to the onset of labor. In these latter cases, labor usually ensues shortly after the membranes rupture. If spontaneous leakage of fluid from the vagina occurs, the designated obstetrical care provider should be notified immediately.
Pregnancy Labor Signs and Symptoms Causes
No one knows exactly what triggers the onset of labor. Some researchers think that hormonal changes within the fetus cause the placenta to produce increased levels of a substance known as corticotrophin-releasing hormone. This changes the balance of the mother's hormones, which have kept the uterus in a relaxed state. Once the process is triggered, the cervix begins to soften and thin out. In most cases, contractions signal the initiation of labor.
Regular exercise during pregnancy is important for your health and well-being. It can improve posture, prevent backaches, decrease fatigue, relieve stress, and build stamina you will need for labor and delivery. It may also help prevent a type of diabetes that develops during pregnancy (gestational diabetes).
Most aerobic, resistance, and flexibility exercises are safe during pregnancy, but because each woman and each pregnancy is different it's important to consult your doctor before starting any exercise program while pregnant.
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.