Labor and Birth Flashcards
Process of Labor - 4Ps
- Labor: coordinated sequence of involuntary, intermittent uterine contractions.
- Birth: the actual event.
- Four major factors (4Ps) interact during normal childbirth:
= Powers (uterine contractions, includes effacement and dilation)
= Passageway (mother’s rigid bony pelvis and the soft tissues of the cervix, pelvic floor, vagina, and introitus)
= Passenger (fetus, membranes, and placenta)
= Psyche (woman’s emotional structure)
Attitude
- is the relationship of the fetal body parts to one another.
- Normal intrauterine attitude is flexion (fetal back is rounded, head is forward on the chest, and arms and legs are folded in against the body.
Lie
- Relationship of the spine of the fetus to the spine of the mother.
- Longitudinal or vertical: fetal spine is parallel to the mother’s
- Transverse or horizontal: fetal spine is at a right angle, or perpendicular, to the mother’s spine.
Presentation
- Portion of fetus that enters the pelvic inlet first.
- Cephalic: head first (has 4 variations - vertex, military, brow, and face).
- Breech: buttocks present first (has 3 variations - frank, full or complete, and footling).
- Shoulder: fetus is in a transverse lie, or the arm, back abdomen, or side could present.
Position
Relationship of assigned area of the presenting part or landmark to the maternal pelvis.
- vertex, face, breech, brow and shoulder presentations.
Station
- the measurement of the progress of descent in cm above or below the midplane from the presenting part to the ischial spine.
- Station 0: at ischial spine.
- Minus station: above ischial spine.
- Plus station: below ischial spine.
- Engagement: when the widest diameter of the presenting part has passed the inlet; corresponds to a ) station.
Mechanisms of Labor: Assessment
- Lightening or dropping: also known as engagement and occurs when the fetus descends in the pelvis about two weeks before birth (most noticeable in first pregnancies).
- Braxton Hicks contractions increase.
- Vaginal mucosa is congested, and discharge increases.
- Brownish or blood-tinged cervical mucus is passed.
- cervix ripens, becomes soft and partly effaced, and may begin to dilate.
- mother has a sudden burst of energy (nesting), often 24 to 48h before onset of labor.
- weight loss of 1-3lb results from fluid shifts produced by changes in progesterone and estrogen levels 24-48h before the onset of labor.
- spontaneous rupture of membranes occurs.
Mechanism of Labor: process
- Engagement: fetus nestles in the pelvis, occurs when presenting part reaches the level of the ischial spines.
- Descent: process that the fetal head undergoes through the pelvis. Continuous process from prior to engagement until birth and is assessed by station.
- Flexion: process of nodding of the fetal head forward toward the chest.
- Internal rotation: assumed at engagement into the pelvis while descending.
- Extension: enables the head to emerge when the fetus is in cephalic position. Begins after the head crowns and is complete when the head passes under the symphysis pubis and occiput.
- Restitution: realignment of the fetal head with the body after the head emerges.
- External rotation: shoulder externally rotate after the head emerges and restitution occurs.
- Expulsion: birth of the entire body.
Leopold’s Maneuvers
- methods of palpation to determine presentation and position of the fetus and aid in location of fetal of fetal heart sounds.
- buttocks feel soft and have an irregular shape.
- fetus’s back is a smooth, hard surface.
- Irregular knobs and lumps, may be the hands, feet, and knees (felt on the opposite side of the abdomen).
Breathing Techniques
- Provide a focus during contractions, interfering with pain sensory transmission.
- promote relaxation and oxygenation.
- divided in first-stage breathing and second-stage.
Fetal Monitoring
- displays the fetal heart rate
- monitors uterine activity
- assesses frequency, duration, and intensity of contractions
- assesses FHR in relation to maternal contractions
- FHR baseline is measured between contractions
- normal at term is 110 to 160 bpm (FHR)
External Fetal Monitoring
- noninvasive
- performed with a tocotransducer or doppler ultrasonic transducer
- ultrasound transducer is placed over the location of the fetal’s back.
- the tocotransducer is placed over the fundus of the uterus.
- position client at comfortable position, avoiding vena cava compression.
Internal Fetal Monitoring
- invasive and requires rupturing of the membranes and attaching an electrode to the presenting part of the fetus.
- client must be dilated 2-3 cm.
Fetal bradycardia or tachycardia
< 110 or > 160 bpm for more than 10 min.
- if either occurs, change the mother’s position, adm oxygen, and assess mother’s VS. Notify PHCP ASAP.
Variability in Fetal Heart Rate
- Fluctuations in baseline FHR
- absent or undetected is considered nonreassuring
- decreased can result in from fetal hypoxemia, acidosis, or certain medications.
- a temporary decrease can occur when fetus is sleeping (do not usually lasts longer than 30 min).
= absent: undetected variability.
= minimal: not more than 5 bpm.
= moderate: fluctuations are 6 to 25 bpm.
= marked: fluctuations are greater than 25 bpm
Accelerations in FHR
- brief, temporary increases of at least 15 bpm and lasting at least 15 seconds.
- usually are a reassuring sign, reflecting a responsive, nonacidotic fetus.
- usually occurs with fetal movement
- may be nonperiodic (no relation to contraction) or periodic (with contractions).
- may occur with uterine contractions, vaginal examinations, or mild cord compression, or when the fetus is in a breech presentation.
Early decelerations
- decreases in FHR (usually remains greater than 100)
- occur during contractions as the fetal head is pressed against the mother’s pelvis or soft tissues, and return to baseline by the end of contraction.
- tracing shows a uniform shape and mirror image of uterine contractions.
- early decelerations are not associated with fetal compromise and require no intervention.
Late decelerations
- are nonreassuring patterns that reflect impaired placental exchange or uteroplacental insufficiency.
- begins well after the contraction and return to baseline after the contraction ends.
- interventions include immediately improving placental blood flow and fetal oxygenation.
Variable decelerations
- caused by conditions that restrict flow through the umbilical cord.
- shape, duration and degree are variable; these fall and rise abruptly with the onset and relief of cord compression.
- also may be nonperiodic, occurring at times unrelated to contractions.
- if occurs, discontinue oxytocin if infusing, change the position of mother, adm oxygen, assess mother’s VS, and notify PHCP.
- assist with amnioinfusion (intrauterine instillation of warmed saline to decrease compression on the umbilical cord) if prescribed.
Hypertonic uterine activity
- assessment includes frequency, duration, intensity of contractions, and resting tone.
- performed either by palpating by hand or with an internal uterine pressure catheter (IUPC).
- uterus should relax between contractions for 60 seconds or longer.
- uterine contraction intensity is about 50 to 75 mmHg (with IUPC) during labor and may reach 110 mmHg with pushing during the second stage.
- average resting tone is 5 to 15 mmHg.
- in hypertonic uterine activity, the resting tone between contractions is high, reducing blood flow and decreasing fetal oxygen supply.
Nonreassuring FHR patterns
- bradycardia
- tachycardia
- late decelerations
- prolonged decelerations
- hypertonic uterine activity
- decreased or absent variability
- variable decelerations falling to less than 70 bpm for longer than 60 seconds.
Priority Nursing Actions for Nonreassuring FHR patterns
- identify the cause
- discontinue oxytocin infusion
- change the mother’s position
- adm oxygen by face mask at 8-10L/min and infuse IV fluids as prescribed
- prepare to initiate continuous electronic fetal monitoring with internal devices if not contraindicated
- prepare for cesarean delivery if necessary
- document the event, actions taken, and the mother’s response.
Four Stages of Labor: Stage 1 (Latent phase)
- the longest
- cervical dilation is 1 to 4 cm
- contractions occur every 15 to 30 min, are 15 to 30 seconds, and mild intensity.
- assist with comfort measures, keep mother and partner informed, offer fluids and ice chips, encourage voiding every 1 to 2 hours.
Four Stages of Labor: Stage 1 (Active phase)
- dilation is 4 to 7 cm
- contractions occur every 3 to 5 min, are 30 to 60 seconds, and moderate intensity
- encourage effective breathing, provide quite environment, keep mother and partner informed, promote comfort with back rubs, sacral pressure, pillow support, and position changes. Instruct partner in effleurage (light stroking of abdomen). Offer fluids and ice chips, encourage voiding every 1 to 2 hours.