Theories of Labor Onset & Signs of Labor PDF

THEORIES OF LABOR ONSET & SIGNS OF LABOR  THEORIES OF LABOR ONSET It is believed that labor is influenced by a combination of factors originating from the mother and the fetus. These factors include the following: 1. Uterine muscle stretching, which results in release of protagland...

THEORIES OF LABOR ONSET & SIGNS OF LABOR  THEORIES OF LABOR ONSET It is believed that labor is influenced by a combination of factors originating from the mother and the fetus. These factors include the following: 1. Uterine muscle stretching, which results in release of protaglandins. 2. Pressure on the cervix, which stimulates the release of oxytocin from the posterior pituitary. 3. Oxytocin stimulation, which works together with prostaglandins to initiate contractions. 4. Change in the ratio of estrogen to progesterone (increasing estrogen in relation to progesterone stimulates uterine contractions) 5. Placental age, which triggers contractions at a set point 6. Rising fetal cortisol levels, which reduce progesterone formation and increase prostaglandin formation. 7. Fetal membrane production of prostaglandin, which stimulates contractions.  Signs of Labor Preliminary Signs of Labor  All pregnant women should be taught these signs so that they can recognize when labor is beginning. 1. Lightening  descent of the fetal presenting part into the pelvis  in primiparas, it occurs approximately 10 to 14 days before labor begins  As the fetus sinks lower in the pelvis, the mother may experience shooting leg pains from the increased pressure on the sciatic nerve, increased amounts of vaginal discharge, and urinary from pressure on the bladder  this changes a woman’s abdominal contour as the uterus becomes lower and more anterior.  gives a woman relief from the diaphragmatic pressure and shortness of breath.  In multiparas, it usually occurs on the day of labor or even after labor has begun 2. Increase in Level of Activity  a woman may awaken on the morning of labor full of energy  this is related to an increase in epinephrine release that is initiated by a decrease in progesterone produced by the placenta  additional epinephrine prepares a woman’s body for the work of labor ahead 3. Braxton Hicks Contractions  In the last week or days before labor begins, a woman usually notices extremely strong Braxton Hicks contractions which she may interpret as true labor contractions  Remind her that if false contractions have become strong enough to be mistaken for true labor, true labor must not be far away 4. Ripening of the Cervix  is an integral sign seen only on pelvic examination  throughout pregnancy, the cervix feels softer than normal, similar to the consistency of an earlobe (Goodell’s sign)  at term, the cervix becomes still softer (described as “butter-soft”)  Ripening is an integral announcement that labor is very close at hand SIGNS OF TRUE LABOR  Signs of true labor involve uterine and cervical changes 1. Uterine Contractions The surest signs that labor has begun is productive uterine contractions Because contractions are involuntary and come without warning, their intensity can be frightening in early labor Helping a woman appreciate that she can predict can control the degree of discomfort she feels by using breathing exercises offers her a sense of control 2. Show As the cervix softens and ripens, the mucus plug that filled the cervical canal during pregnancy(operculum) is expelled The exposed cervical capillaries seep blood as a result of pressure exerted by the fetus The blood mixed with mucus, takes on a pink tinge and is referred to as “show” or “bloody show” Women need to be aware of this event so that they do not think they are bleeding abnormally 3. Rupture of Membranes Labor may begin with rupture of the membranes, experienced either as a sudden gush or as scanty, slow seeping of clear fluid from the vagina Two risks associated with ruptured membranes are: 1. intrauterine infection 2. prolapse of the cord which can cut off the oxygen supply to the fetus In most instances, if labor has not spontaneously occurred by 24 hours after membrane rupture and the pregnancy is at term, labor is induced to help reduce these risks Differentiation Between True and False Labor Contractions False Contractions True Contractions  Begin and remain irregular  Begin irregularly but become regular and predictable  Felt first abdominally and remain  Felt first in lower back and sweep confined to the abdomen and around to the abdomen in a wave groin  Often disappear with ambulation  Continue no matter what the and sleep woman’s level of activity.  Do not increase in duration,  Increase in duration, frequency, frequency or intensity and intensity  Do not achieve cervical  Achieve cervical dilatation dilatation