Labor and Delivery Flashcards
Theories about what causes labor
- Progesterone withdrawal (estrogen-progesterone ratio changes)
- Increased release of prostaglandins
- Increased oxytocin sensitivity
Premonitory Signs of Labor
- Lightening
- Braxton-Hicks contractions
- Cervical ripening
- Bloody show
- Sudden burst of energy
- 1-3 pound weight loss
- Diarrhea, indigestion, or nausea and vomiting
- Rupture of membranes
Describe True Labor Contractions
- At regular intervals
- Intervals between contractions gradually shorten
- Increase in duration and intensity
- Discomfort begins in back and radiates around to abdomen
- Intensity increases with walking
- Do not decrease with rest
Factors Affecting Labor
- Birth passage
- Fetus
- Relationship between the passage and the fetus
- Physiological forces of labor
- Psychological considerations
Factors Affecting the Birth Passage
- Size of the maternal pelvis
- Type of maternal pelvis
- Ability of the cervix to dilate and efface
- Ability of the vaginal canal and the external opening of the vagina (introitus) to distend
What is the best and most common type of pelvis?
Gynecoid
What is presentation?
The body part of the fetus that enters the pelvic passage first (referred to as the presenting part)
What are the different types of presentation?
- Cephalic (also called vertex)
- Breech (buttocks and/or feet)
- Shoulder (transverse lie)
What is position?
Refers to the relationship between a designated landmark on the presenting part and the front, sides, or back of the maternal pelvis
What are the position landmarks?
- Occipital bone (vertex)
- Breech (sacrum)
- Shoulder (scapula)
Positions of fetal occiput in relation to Mom’s pelvis
- Anterior
- Posterior
- Transverse
What is station?
Refers to the relationship of the presenting part to an imaginary line drawn between the ischial spines of the maternal pelvis
-Measures the degree of descent of the presenting part of the fetus (in cm) through the birth canal
Degrees of station
- (-) above spines
- (0) station = engaged; at level of spines
- (+) below spines
What is engagement?
Occurs when the largest diameter of the presenting part reaches or passes through the pelvic inlet
- When engagement occurs, the presenting part is at the level of the ischial spines
What are primary physiologic forces of labor?
Uterine muscular contractions which cause CERVICAL CHANGES during the firs stage of labor
What are secondary physiologic forces of labor?
Use of abdominal muscles to push during the second stage of labor (helps the baby come out)
What are the cervical changes in the first stage of labor?
- Effacement
2. Dilation
What is effacement?
The shortening and thinning of the cervix
- Described in percentages
What is dilation?
- Opening of the cervix
- Described in cm
- When the cervix widens to a diameter of 10 cm, it is considered completely dilated
Physiologic Responses to Labor (Maternal)
- WBC increases
- Temp increases
- HR, CO, RR, BMR increase
- GI motility decreases
- Glucose decreases
Physiologic Responses to Labor (Fetal)
- Periodic HR changes
- Decreased fetal movement
- Decreased circulation and perfusion
First Stage of Labor
- Begins with the onset of true labor (regular contractions)
- Ends when the cervix is completely dilated at 10 cm
- Divided into 3 phases
What are the three phases in the first stage of labor?
- Latent (early) 0-3 cm dilated
- Active 4-7 cm dilated
- Transition 8-10 cm dilated
Describe the contractions in the latent phase
- Frequency - widely spaced
- Duration - short
- Intensity - begin as mild and progress to moderate
Appearance/Behavior of the mother during the latent phase
- Relieved that the labor has started
- Excited
- Anxious
- Eager to talk about herself and answer questions
- Feels able to cope with discomfort
Describe the contractions during the active phase of labor
- Frequency - regular pattern
- Duration - increasing
- Intensity - begin as moderate and progress to strong
Appearance/Behavior of the mother during the active phase of labor
- Anxiety tends to increase as contractions and pain increase
- Begins to fear a loss of control
- May use a variety of coping mechanisms or exhibit decreased ability to cope and a sense of helplessness
Describe the contractions during the transition phase
- Frequency - definite pattern (2-3)
- Duration - (60-90 seconds)
- Intensity - strong by palpation
Appearance/Behavior of mother during the transition phase of labor
- Severe pain
- Increased apprehension and irritability
- Sense of powerlessness or loss of control
- Intense physical sensations: increasing rectal pressure and feeling the urge to bear down, nausea/vomiting, shaking
Second Stage of Labor
- Begins when the cervix is completely dilated and effaced
- Ends with the birth of the baby
- Length:
- Primigravida: up to 3 hours
- Multiparas: less than 1 hour; averages 15 minutes - Early in this stage the fetus descends passively through the birth canal as the uterus contracts
- Have patient rest and begin pushing only after she feels the urge to push
- Use gravity to help with fetal descent
Mechanisms of Labor
- Engagement
- Descent
- Flexion
- Internal rotation
- Extension
- External rotation
- Expulsion
Third Stage of Labor
- Begins with birth of baby
- Ends with delivery of the placenta
- Stage 3 should last a maximum of 30 minutes
Signs of placental separation
- Globular-shaped uterus
- Fundus rises in the abdomen
- Sudden gush or trickle of blood
- Further protrusion of the umbilical cord out of the vagina
Fourth Stage of Labor
- First 1-4 hours after birth
- Physiologic recovery
- Family formation
Causes of pain during first stage of labor
- Dilation of the cervix
- Stretching of the lower uterine segment
- Pressure on adjacent structures
- Hypoxia of the uterine muscle cells during contractions
Causes of pain during the second stage of labor
- Hypoxia of the contracting uterine muscle cells
- Distention of the vagina and perineum
- Pressure on adjacent structures
Causes of pain during the third stage of labor
- Uterine contractions and cervical dilation as the placenta is expelled
Factors affecting responses to pain
- Preparation for childbirth
- Culture
- Fatigue/sleep deprivation
- Previous experiences with pain
- Anxiety level
What is the goal for pain relief during labor?
To provide maximum analgesia with minimal risk for the mother and fetus
Opioids that can be given during labor
- Butorphanol
- Nalbuphine
- Meperidine
- Fentanyl
Antiemetics that can be given during labor
- Hydroxyzine
2. Promethazine
Benzodiazepines that can be given during labor
- Diazepam
2. Midazolam
Butorphanol
- Is both a narcotic agonist and antagonist
- May cause withdrawal in narcotic-dependent patients
- May be reversed with Narcan (Nalaxone)
Maternal side effects of butorphanol
- “Floating” feeling
- Sedation
- Respiratory depression
- Hallucinations
- Urinary retention
Butorphanol dosage, onset, peak, and duration
- Usual dose is 1-2 mg slow IVP q 3-4 hours
- Onset of action occurs in 1-2 minutes
- Peak analgesia occurs in 30-60 minutes
- Duration is 3-4 hours