Final Flashcards
Labor - Definition (long)
- Sequential, integrated set of changes with the myometrium, decidua, and uterine cervix that occur gradually over a period of days to weeks
- Change in myometrial contractility pattern from “contractures,” a pattern of long-lasting low-frequency activity, to “contractions,” high-intensity high-frequency activity resulting in effacement and dilation of the uterine cervix
Labor - Definition (short)
- Clinical diagnosis
- Regular uterine contractions
- Progressive cervical effacement
- Progressive uterine dilation
“False” Labor - Definition
- Regular uterine contractions
- No change in cervical dilation
Term Pregnancy - Definition
- 37 - 42 weeks
Onset of Labor - Hormones/factors Involved in Parturitional Cascade
- Prostaglandins
> Increased prostaglandins, especially PGE2 and PGF2, near initiation of labor soften cervix and can help cause contractions - Progesterone
> Progesterone withdrawal does not occur in all women before labor - Estrogen
> Up-regulates receptors on uterus, increasing contractility
Onset of Labor - Oxytocin
- Synthesized in the hypothalamus and released from the posterior pituitary
- Stimulates uterine contractions
- Circulating levels of oxytocin do not change significantly during pregnancy or prior to the onset of labor
- Uterine myometrial receptors become increasingly sensitized to oxytocin during the second half of pregnancy
- Unlikely to stimulate labor, but definitely makes stronger uterine contractions
Onset of Labor - Role of the Fetus
- Not well understood
- Potentially controls the timing and onset of labor, possibly due to increased fetal pituitary-adrenal activity
First Stage of Labor - Definition
- Interval between the onset of labor and full cervical dilation (10cm)
First Stage of Labor - Latent Phase
- Characterized by slow dilation
- Period between onset of labor and point at which the rate of cervical dilation increases **(up to 4cm dilation)
- *- Contractions often 5-10 minutes apart, lasting 30-45 seconds
- AKA: “early labor” or “prodromal labor”
First Stage of Labor - Active Phase
- Characterized by a faster rate of dilation
- *- Usually begins by 4cm dilation
- *- Contractions often 2-4 minutes apart, lasting 60 seconds, more intense
- “active labor”
First Stage of Labor - Transition
- Characterized by a mix of cervical dilation and descent of fetus
- *- 7-10cm
Second Stage of Labor - Definition
- Characterized by the descent of the fetus through the maternal pelvis
- *- Interval between full cervical dilation (10cm) and delivery of infant
- There is usually a maternal desire to bear down with contractions and a sensation of pressure on the rectum
Management of Normal L&D - Onset of Labor
- Regular firm contractions
- Bloody show
- Spontaneous rupture of membranes
First Stage Initial Evaluation
- Establish baseline cervical status
- Review prenatal record for medical conditions
- Check for development for new disorders
- Evaluate fetal status
- Vitals
> BP
> Pulse
> Temperature - Fetal heart rate
- Frequency, duration, and strength of contractions
- Cervical examination (may defer if the membranes are ruptured)
> Dilation of cervix (0-10cm)
> Effacement of cervix (0-100%)
> Status of fetal head (-5cm - +5cm)
> Status of amniotic membranes/presence of meconium
> Presentation and position of fetus
Monitoring During Labor
- Vitals every 4 hours (1-2 hours if abnormal)
- Assessment of uterine contractions
- Cervical examinations
> On admission
> 1-4 hour intervals during first stage
> 1 hour intervals during second stage
> When patient feels urge to push
> With any fetal heart rate abnormalities - Fetal heart rate
> Not mandatory for low-risk
> Every 15 - 60 minutes during first stage
> Every 5 minutes during second stage
> Listen during and after contractions
> Normal range is 110 - 160bpm
Activities During Labor
- Food and drink should not be limited during labor for low-risk patients
> Suggest juices, popsicles, broth, yogurt, crackers, fruit - Encourage patient to empty their bladder frequently
- Give patient information
- Give patient privacy
- Factors associated with a satisfactory birth
> Personal expectations met
> Caregiver support
> Participation in decision making - Coaching
> Involve partner
> Soothing, calm tone of voice
> Give her visual images
> Acknowledge what she is experiencing
> Remind her that it will end and there will be breaks
> Give her positive feedback - Encourage patient to change positions fequently
> Standing, sitting, side-lying, squatting, hands-and-knees, kneeling - Pain relief/comfort measures
> Position changes
> Massage
> Counter-pressure
> Warm water
> Encouragement
> Homeopathy
> Emotional support
Labor Augmentation
- Hydration (oral or IV)
- Calories
- Position changes
- Acupuncture
- Homeopathy
- Herbs
- Breast pump
- Amniotomy
Second Stage of Labor - Details
- Push at either 10cm or when patient has urge to push
- Can use valsalva or physiologic (however patient wants) positions to push
- Length of second stage
> Primiparous average around 2 hours, but can push longer if there’s progress and no distress
> Multiparous average 1 hour or less - Episiotomy (unnecessary in normal births) indications:
> Fetal distress at +4 station
> Prolonged crowning
> Need for instrumentation
Delivery - Steps in Assisting Birth
- Patient pushes to crowning
- Encourage patient to pant or give little pushes at crowning to stretch the perineum
- One hand on vertex of fetal head to keep head flexed
> Possibly apply counter-pressure - Other hand supports the perineum
- After head is delivered, allow for spontaneous restitution
> Restitution = baby’s rotational position changing to help deliver shoulders AP in pelvis
**- Reduce nuchal cord (cord around baby’s neck), if present - With next contraction, apply gentle downward traction toward the maternal sacrum to deliver the anterior shoulder
- As soon as the anterior shoulder becomes visible, deliver the posterior shoulder with upward traction
Third Stage of Labor - Definition
- Interval between fetal delivery and complete expulsion of the placenta
Third Stage of Labor - Length
- Risk of postpartum hemorrhage (PPH) increases with length of third stage
- Lengths
> Average length is 5-6 minutes
> 90% by 15 minutes
> 97% within 30 minutes - Gestational age is the major factor influencing the length of the third stage
> Pre-term deliveries are associated with a longer third stage
Third Stage of Labor - Cord Clamping
- Often done by a family member
- 75% of placental blood is transferred to infant in the first minute
- Benefits of delayed cord clamping
> Higher hemoglobin levels
> Lower rates of anemia in ages 2-6 months
> Important for babies whose mothers have low ferritin
> Important for babies who will be breastfed without iron supplementation
> Important for low birth weight babies
> Lower risk for necrotizing enterocolitis
> Less intraventricular hemorrhage - Disadvantages of delayed cord clamping
> Higher rate of polycythemia
> Greater need for phototherapy for term infants with jaundice
Third Stage of Labor - Cord Milking
- Alternative to delayed clamping
- Might help stabilize BP and increase urinary output in preemies
- Milking the cord 4x roughly equals 30 seconds of delayed clamping
> Similar benefits and disadvantages - Should not delay delivery or treatment in order to milk the cord
- Should not milk the cord if planning to collect cord blood
Third Stage of Labor - Cord Blood
- For diagnostic purposes
> Allow blood to drain from the cut end into a glass tube prior to delivery of the placenta
> May be screened for type and Rh, as well as any necessary newborn conditions
> Not used for pH testing (collect for that using needle into umbilical artery) - For banking purposes
> Can be done with placenta in utero or ex utero
Third Stage of Labor - Placental Delivery
**- Signs of placental shearing
**> Gush of blood
**> Umbilical cord lengthening
**> Uterus becomes firmer and globular
**> Uterus moves upward
- Placental expulsion
> Spontaneous uterine contractions and patient bearing down
> Expectant management
^ Follows natural physiology
^ Usually involves delayed cord clamping
^ Monitor patient’s vitals, bleeding, and for signs of placental shearing
^ Placenta will be expelled naturally
> Active management
^ Typically does not shorten third stage, but does lessen blood loss
^ Early cord clamping, cord traction, and prophylactic oxytocics
- Technique
> When tractioning the cord, prevent uterine prolapse by guarding the uterus
> Immediate nursing and/or nipple stimulation does not prevent PPH or significantly decrease blood loss
> Excessively massaging the uterus could negatively impact placental shearing and contribute to PPH
> Patient in upright position will help placental expulsion
**- Retained placenta
**> Herbal angelica
**> Homeopathic pulsatilla or sabina
- After normal delivery of placenta
> Check for firm uterus every 5-10 minutes to control bleeding
> Fundus should feel hard and be near the level of the umbilicus
> 1 cup of fluids every hour patient is awake
> Stay in bed for 2 days minimum except to use the bathroom
> Can shower after 12 hours if no dizziness or hemorrhaging