COMPONENTS OF LABOR:1]. BIRTH PASSAGE:

a). Size of pelvis

b). Type of pelvis

c). Ability of the cervix to dilate and efface.

d). Ability of Vaginal canal and external opening to distend.

PELVIC TYPE CHARACTERISTICS IMPLICATIONS FOR BIRTH

GYNECOID Inlet and midpelvis diameters adequate. Inlet is rounded.Outlet adequate.

Favorable for vaginal birth.

ANDROID Inlet: heart-shaped w/ posterior sagittal diameter.Midpelvis and oulet reduced.

Not favorable. Descent into pelvis is slow. Fetal head enters w/ arrest of labor frequent.

ANTHROPOID Inlet: oval; long-anteroposterior.Midpelvis and outlet adequate.

Favorable.

PLATYPELLOID Inlet: oval, long transverse.Midpelvis reduced.Outlet capacity inadequate.

Not favorable. Fetal head engages in transverse. Difficult descent. Frequent delay of progress at outlet.

TYPE

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BONES

2]. THE FETUS:

a). Fetal head

-size and molding(overlapping of cranial bones due to pressure).

b). Fetal attitude

-vertex (hyperflexion of the fetal head in engagement).

-brow (extension of the fetal head in engagement).

-chin (hyperextension of the fetal head in engagement).

c). Fetal lie

-longitudinal lie- head of fetus is parallel to mother’s spine.

-transverse lie- fetus is at a right angle to the mother’s spine.

d). Fetal presentation

-cephalic- when head of fetus is pointing at the outlet.

-breech- when fetal head is in the fundus area.

-shoulder-the shoulder is the engaged part.

e). Placenta

-Schultze mechanism: when placenta is expelled with the fetal(shiny) part presents.

-Duncan mechanism: or dirty duncan because maternal(rough) part is presenting.

3]. RELATIONSHIP BETWEEN THE PASSAGE AND THE FETUS:

a). Engagement of fetal presenting part.

- occurs when the largest diameter of the presenting part reaches or passes through the pelvic inlet.

b). Station.

- Refers to the relationship of the presenting part to an imaginary line drawn between the ischial spines of the maternal pelvis.

c). Fetal position

-Refers to the relationship of a designated landmark on the presenting fetal to the front, sides, or back of the maternal pelvis.

4]. PRIMARY SOURCES OF LABOR:

a). Frequency: time between beginning of one contraction to the next.

b). Duration: beginning of one contraction to the end of the same.

c). Intensity: strength of contraction during acme.

d). Effectiveness of the maternal pushing effort

e). Duration of labor

5]. PSYCHOSOCIAL CONSIDERATIONS:

a). Physical preparation for childbirth

b). Sociocultural values and beliefs

c). Previous childbirth experience

d). Support from significant others

e). Emotional status

PHYSIOLOGY OF LABOR ONSET:

THEORIES ON LABOR ONSET …

Process of labor usually begins between the 38th and 42nd week of gestation, when fetus is mature and ready for birth. Important aspects were identified:

- Progesterone relaxes smooth muscle tissue

- Estrogen stimulates uterine muscle contractions

-Connective tissue loosens to permit the softening, thinning and opening of cervix.

*Progesterone Withdrawal Hypothesis:

Progesterone produced by the placenta relaxes the uterine smooth muscles by interfering with the conduction of one cell to the next. During pregnancy, quieting of progesterone permits estrogen to better stimulate contractions. Toward end of gestation, biochemical changes decrease the availability of progesterone to myometrial cells and associated with antiprogestin that inhibits the relaxing effect.

*Prostaglandin Hypothesis:

Once prostaglandin is produced, stimuli for its synthesis may include rising levels of estrogen, decreased progesterone and increased levels of oxytocin, platelet-activating factor and endothelin-1.

*Corticotropin-releasing Hormone:

CRH increases during pregnancy. Plasma CRH increases prior to preterm labor and CRH levels are elevated in multiple gestation. Also known to stimulate the synthesis of prostaglandin F and E by amnion cells.

SIGNS OF LABOR:

PREMONITORY SIGNS OF LABOR:

a). Lightening – fetus begins to settle into pelvic inlet (engagement).-leg cramps or pain (due to pressure on nerves)- increased pelvic pressure- increased venous stasis leading to edema- increased vaginal secretions

b). Braxton Hicks contractions – irregular and intermittent contractions.

c). Cervical Changes – ripening or softening of the cervix to allow flexible passage.

d). Bloody show – pink tinged secretions.

e). Rupture of membranes – amniotic fluid may be expelled in large amounts, if fetal head isn’t engaged, there is probability of prolapsed cord.

f). Weight loss of 1 to 3lb resulting from fluid loss and electrolyte

g). Diarrhea, indigestion or nausea

DIFFERENCE BETWEEN TRUE AND FALSE LABOR:

-TRUE LABOR:

Produce progressive dilation and effacement of the cervix.

Occur regularly with increase in frequency, duration and intensity.

Discomfort starts at the back and radiates around the abdomen.

Pain is not relieved by ambulation.

-FALSE LABOR:

Irregular.

Do not increase in frequency, duration and intensity.

Discomfort occur mainly in the lower abdomen or groin.

Vice versa of the above statements in true labor.

STAGES OF LABOR AND BIRTH: 1ST STAGE:PHASES: CHARACTERISTICS:

LATENT PHASE Uterine contractions occur and increase in frequency, intensity, duration.Amniotic membranes bulge through the cervix in the shape of a cone.Spontaneous rupture of membranes (SROM) occur intensely.Artificial rupture of membranes (AROM) or amniotomy occur when certified health officials rupture the membrane using a amnihook.

ACTIVE PHASE Anxiety and intensities increase. During this phase, the cervix dilates from about 3 to 4 cm, to 8cm. Fetal descent is progressive. Cervical dilatation averages 1.2 cm per hour (nulliparas) and 1.5 cm per hour in multiparas.

TRANSITION PHASE

Entering this phase, the mother will already be tired. Contractions frequently occur every 2mins. Duration of 60-90 sec. and very strong intensity. Fetal descent dramatically increases. Other characteristics:-Increasing bloody show -difficulty in understanding directions-Hyperventilation -bewilderment-Generalized discomfort -request for medications-Increased need for partner - nausea-Restlessness -beads of perspiration-Increased irritability -increasing rectal pressure

2nd STAGE:

begins with complete cervical dilatation.

descent of the fetal presenting part continues until it reaches the perineal floor.

3RD STAGE:

placental delivery.

appear about 5mins after birth.

signs include:

- globular-shaped uterus

- rise of fundus in the abdomen

- sudden gush or trickle of blood

- further protrusion of the umbilical cord out of the vagina.

4TH STAGE:

mother’s time. From 1-4 hours after birth.

monitoring maternal state.

ANALGESIC AND ANESTHESIA:ANALGESICS:

a). Narcotic agents are injected into the circulation have their primary action at sites in the brain, activating the neurons to the spinal cord.

ex: Butorphanol Tartrate (stadol)

Nalbuphine Hydrochloride (nubain)

b). Analgesic Potentiators aka ataractics, can decrease anxiety and increase effectiveness.

ANESTHESIA:

Regional Anesthesia: temporary loss of sensations.

Esters, Amides and Opiates – local anesthetic agents.

Spinal Block: local anesthetic agents is injected directly into the spinal fluid in the spinal canal. Immediate onset of anesthesia. Need for smaller drug volume.

DANGER SIGNS DURING LABOR AND DELIVERY:

a). Hypertonic labor patterns:

-Increased discomfort due to uterine muscle cell anoxia.

-Fatigue as the pattern continues and no labor progress results.

-Stress on coping abilities.

-Dehydration and increased incidence of infection.

-Non-reassuring fetal status with uteroplacental exchange.

-Prolonged pressure on fetal head.

b). Precipitous Labor:

-Loss of coping abilities.

-Lacerations of the cervix, vagina and perineum due to rapid descent of fetus.

-hypoxia

-Cerebral trauma

-Pneumothorax

c). Post term pregnancy:

-Probable labor induction.

-Increased risk for LGA infant.

-Increased incidence for forceps-assisted.

-Increased psychologic stress

-Decreased perfusion from the placenta.

-Meconium aspiration.

d). Fetal malposition:

-Risk for third or fourth degree perineal lacerations

-Risk for extension of a midline episiotomy.

e). Macrosomia:

-CPD

-Dysfunctional labor

-Soft-tissue laceration

-meconium aspiration

-asphyxia

NURSING DIAGNOSIS AND CARE DURING LABOR:

1st STAGE:

‘ Emotional support‘ comfort measures‘ info and advice‘ advocacy‘ support from the partner

2nd STAGE:

‘ promotion of comfort‘ assisting during birth‘ position teachings‘ cleansing the perineum‘ continued labor support

3rd AND 4TH STAGE:

‘ initial care of the newborn‘ care of umbilical cord‘ blood collection‘ inspection‘ stable vital signs‘ no bleeding‘ undistended bladder‘ firm fundus‘ sensations fully recovered