1st Stage of Labor Flashcards
1
Q
1st stage of labor
A
- Begins with true labor contraction, as evidenced by progressive cervical change, and ends when the cervix is completely dilated (approximated at 10 centimeters) and ready for passage of the fetal presenting part
- Stage of cervical dilatation
2
Q
Identify the two phases of the 1st stage of labor, and the three parts of the active phase according to Friedman
A
- 2 phases:
- Latent phase begins with the onset of regular uterine labor contractions until cervical dilation progresses rapidly
- end of the latent phase for multiparous women ~ 6 cm (no marker for nulliparous)
- contractions start to increases in intensity and frequency
- usually little to no decent of presenting part
- Active phase begins when the rate of cervical dilation increases
- typically see decent of fetal presenting part in latter part of active stage
- 3 parts of active phase per Dr. Friedman:
- Acceleration phase,
- Phase of maximum slope
- Deceleration phase
- Labor progress slows between 8 and 10 centimeters of cervical dilation but is controversial
- Latent phase begins with the onset of regular uterine labor contractions until cervical dilation progresses rapidly
3
Q
Define true versus false labor
A
- “False labor”- historically used to describe uterine contractions of varying intensity that are not associated with progressive cervical change over time.
- Intensification of the usually painless Braxton Hicks contractions
- “Prelabor contractions” more accurate, body-affirming term
- do not intensify over time and may be relieved by walking or position changes vs. true labor contractions intensify over time, becoming longer, stronger, and closer together.
- May occur for days or intermittently for weeks before the onset of true labor → may fatigue over time and have difficulty coping, as these contractions can be painful and distressing.
- True labor contractions sometimes intensify with walking and are not relieved by position changes.
- Associated with progressive cervical change.
4
Q
Define bloody show and differentiate it from frank bleeding
A
- Mucus plug created by cervical secretions from proliferation of the glands of the cervical mucosa early in pregnancy → seals the cervical canal throughout pregnancy → protective barrier.
- Cervix ripens → small capillaries may break → blood mixes with mucus → bloody show is the expulsion of this blood-tinged mucus.
- The mucus associated with bloody show is thick and tenacious.
- Both history and examination can help differentiate benign bloody show from frank bleeding.
- Usually expelled over the course of several days, and noticed by the patient as mild irregular spotting when wiping after urination or defecation.
- Usually signals the onset of labor within the next few days.
- Not accurate if recent vaginal examination or sexual intercourse due to minor trauma to the ripening cervix or disruption of the mucus plug.
5
Q
Identify signs of impending labor
A
- Descent of the fetus - lightening
- more common in nulliparous women
- Cervical changes
- Reassuring suggestive of progress toward true labor but not a reliable predictor of actual labor onset.
- Relative to the individual patient and their parity
- Increase in uncoordinated uterine contractions
- Rupture of membranes
- Prelabor ROM occurs in ~ 8% - 10% of term pregnancies, 95% of whom will begin labor spontaneously within 33 to 107 hours after rupture, if given this time.
- Bloody show or increased mucus discharge from the vagina
- Maternal perception of increased energy
- Gastrointestinal distress
- Increased production of prostaglandins and estrogen and the decrease in progesterone levels that occur with the approach of labor
6
Q
Discuss the advantages and disadvantages of various maternal positions and activities during the first stage of labor
A
- Patients in upright positions have shorter labor durations by ~1 hour and are less likely to have an epidural or cesarean birth, compared to patients who maintain recumbent positions.
- Creative use can be made of furniture, pillows, birthing balls, or an adjustable bed to support a laboring person in a variety of upright positions, including hands and knees, sitting, standing, and squatting.
- If resting in bed is necessary or desired - lateral recumbent positions are preferred to supine positions (reduce the potential for aortic/venae cavae compression → maternal hypotension and potential fetal compromise).
- facilitate kidney function and don’t interfere with coordination and efficiency of uterine contractions
7
Q
Describe the needs of the laboring woman pertaining to rest/activity and measures to meet these needs
A
- Level of physical activity and positions used during labor are ideally those chosen by the laboring person
- People with medical or obstetric conditions (severe PEC, placental abruption, or acute infections) need activity restriction due to their physiologic instability, the effect of medications, or increased fetal risk requiring continuous electronic fetal monitoring.
- People with physical mobility disabilities may require additional modifications to facilitate comfort and labor progression.
- People w/hx of sexual/physical abuse may find any position such as lithotomy, or having providers stand over her, a trigger of previous trauma
8
Q
Indications for IV access
A
- Not needed routinely
- Decision to initiate/maintain IV access based on actual or potential risk factors for each patient:
- Cannot tolerate oral fluid intake
- Administration of some medications, such as antibiotic prophylaxis for GBS
- Pain medications
- Oxytocin augmentation
- Prior to initiation of epidural anesthesia
9
Q
Discuss advantages, disadvantages and expected results of amniotomy based upon current evidence
A
- Amniotomy in conjunction with oxytocin for induction or to prevent dystocia in patients with mild labor delays - decrease in labor duration associated with amniotomy may be statistically significant but not clinically relevant.
- Reduced risk of cesarean birth is significant but modest.
- Amniotomy alone does not appear to be a beneficial treatment for people with active-phase arrest.
- AROM in patients who do not have dystocia was associated with a trend toward an increased risk for cesarean birth
10
Q
Discuss releasing/rupturing the membranes
A
- Before performing AROM, carefully reassesses the fetal station and ensures the fetal head is well applied to the cervix.
- Keeping the fingers in the cervix, the membranes can be gently disrupted with the Amniohook.
- Avoid scratching the fetal head and the clinician’s fingers should be left in place during the initial gush of fluid to ensure a prolapsed cord does not occur.
- Assessed FHR during the procedure and monitor frequently for a short time afterward.
11
Q
Identify rationale and criteria for safe elective amniotomy
A
- Treatment of dystocia
- Adjunct intervention for patients who have a clear indication for induction of labor
- When internal monitoring is required
12
Q
Discuss factors, which influence time interval for checking maternal vital signs, and determine appropriate intervals
A
- Frequency varies among settings - typically detailed in an institutional policy to ensure adherence to a minimum standard.
- Common schedule for patient (without epidural anesthesia) during the 1st stage of labor who does not have a specific condition that would require more frequent monitoring:
- BP, HR, and RR: q hour
- Temperature:
- q 2 to 4 hours when normal and the membranes are intact
- q 1 to 2 hours if abnormal and/or after the membranes have ruptured
13
Q
Describe appearance of distended bladder during labor and its effect on uterine action
A
- A distended bladder may appear as a bulge above the symphysis pubis
- in severe cases may extend as high as the umbilicus.
- When the fetus is in a posterior position, the contour of the patient’s abdomen may look as though she has a full bladder (must then ruled it out)
- A distended bladder can impede the progress of labor by preventing fetal descent as well as increasing the discomfort and pain in the lower abdomen that patients frequently experience during labor.
- In the 3rd stage of labor can inhibit the ability of the uterus to contract effectively → risk of PPH 2° to uterine atony.
- Bladder hypotonicity, urine stasis, and infection during the postpartum period can result from traumatic pressure exerted on a distended bladder during labor.
14
Q
Identify and discuss factors which determine appropriate times for checking progress of normal labor by internal exam
A
Indications during normal 1st stage labor:
- Establish an informational baseline - can be used for appropriately timing further examinations to establish labor status prior to admission or labor interventions (prelabor, latent, or active labor)
- As an appropriately timed 2nd examination to determine the woman’s labor state prior to labor admission (prelabor, latent, or active labor)
- Inform management decisions related to management of labor pain
- Verify complete dilation
- Check for a prolapsed cord after SROM if a prolapsed cord is a suspected risk (e.g., ballottable presenting part or fetal heart rate decelerations that do not resolve with usual maneuvers)
Appropriate to wait several hours prior to doing a cervical examination as the cervix changes in early active labor (e.g., from 4 cm to 5 cm), but not later in labor (e.g., between 8 cm and 9 cm).
15
Q
Identify and discuss signs and symptoms indicative of labor progress other than cervical exam findings
A
Astute observation of the patient:
- Behavior
- Contraction pattern
- Signs and symptoms of transition into 2nd-stage labor
- Change of location of back pain
- Change in location of maximum intensity of fetal heart tones
- Change in position of fetal heart tones
18
Q
Identify the average length of the phases of first stage labor in a nullipara and multipara according to current evidence
A
- Latent (according to Gabbe)
- Nullipara - 7.6 - 8.3 hours
- Multipara - 4.1 - 5.3 hours
- Active (according to Varney)
- Starts at ~6 cm
- Nullipara - 2.2 hours
- Multipara - 1.3-1.6 hours
Dystocia limits:
- Nulliparas: less than 0.5 to 0.7 cm/hr dilation
- Multiparas: 0.5–1.3 cm/hr dilation, with faster dilation as labor progresses
