PANCE Prep- GYN Flashcards
Uteroplacental insufficiency occurs when the uteroplacental unit is compromised. Initial fetal responses include:
- fetal hypoxia,
- shunting of blood flow to the fetal brain, heart, and adrenal glands, and
- transient repetitive late decelerations of the fetal heart rate
*If hypoxia continues the fetus will eventually switch over to anaerobic glycolysis and develop metabolic acidosis –> lactic acid accumulates and progressive damage to vital organs occurs
A normal fetal HR is ___ and it Usually ___ w/ contractions
110-160bpm
increases w/ contractions
<110= bradycardia >160= tachycardia
___ after contractions are abnormal and can indicate stress
____ to baseline is particular omnious
Decelerations
*indication for “operative intervention” if persistent
Slow recovery to baseline
The most common cause of fetal tachycardia is
- chorioamnionitis
- (aka intra-amniotic infection (IAI)– inflammation of the fetal membranes (amnion and chorion) due to a bacterial infection- E. coli, GBS)
Other causes:
- Maternal fever
- Thyrotoxicosis
- Medication
- Fetal cardiac arrhythmias
Moderate variability in FHR is a reassuring sign that reflects adequate fetal oxygenation and normal brain function
Decreased variability associated with:
- Cardiac or CNS anomalies
- Hypoxia (fetal)
- Acidemia
- Tachycardia (fetal)
- Prematurity
- Depressed CNS (meds)
- Fetal sleep
- Prolonged uterine contraction
(CHATPDFP)
At 32 weeks and beyond, an acceleration has a peak of __bpm or more above baseline, with a duration of __ seconds or more but less than __minutes
Before 32 weeks, an acceleration has a peak of __ bpm or more above baseline, with a duration of __ seconds or more but less than __ minutes
15bpm– 15sec but less than 2 min
10bpm– 10 sec but less than 2 min
Prolonged acceleration lasts __ minutes or more but less than __ minutes
2 min but less than 10 min
*If longer than 10 minutes, it is a baseline change
What are early decelerations
-Associated with uterine contractions –> nadir of the deceleration occurs at the SAME TIME as the peak of the uterine contraction (“Mirror image” of the contraction)
- Usually symmetrical gradual decrease and return
- Result of pressure on the fetal head from the birth canal, digital exam, or forceps application that causes a reflex response through the vagus nerve with acetylcholine release at the fetal SA node
**Physiologic, not a cause of concern
Late decelerations are associated w/
uteroplacental insufficiency, as a result of either decreased uterine perfusion or decreased placental function –> decreased intervillous exchange of oxygen and CO2 and progressive fetal hypoxia and acidemia
What is the most common period fetal HR pattern
variable decelerations
*usually associated w/ umbilical cord compression– often correctable by changes in maternal position to relieve pressure on the umbilical cord
How often do you evaluate a continuous electric monitoring tracing during the active phase of 1st stage labor?
low risk: at least every 30 min
high risk: at least every 15 min
How often do you evaluate a continuous electric monitoring tracing during the 2nd stage labor?
low risk: at least every 15 min
high risk: at least every 5 min
A good reassuring fetal HR strip is indicated by
- long term variability w/ baseline HR 120-160
- accelerations (increase in 15bpm) for at least 15 sec above baseline
- no decelerations
Causes of increase in fetal HR
- fetal movement
- contractions
- sounds or other stimuli like scalp stimulation
*accelerations= good fetal well being
tx of late decelerations
- reposition mom on left (off VC)
- maternal fluid bolus (increase BP) and O2
- decrease pitocin (decrease contractions)
- administer terbutaline to decrease contractions frequency
- C-section
Nonstress test evaluates the fetal heart rate response to fetal activity. It measures the fetal heart rate, patterns, and accelerations, which are monitored with an external transducer for at least 20 minutes. The tracing is observed for fetal heart rate accelerations. Patient asked to note fetal movement by pressing a button on the monitor which causes a notation on the monitor strip
- Results are considered reactive (reassuring) if: ___
- Nonreactive (nonreassuring) tracing is: __
- Reassuring: if 2 or more FHR accelerations occur in a 20 minute period
- Nonreactive: one without sufficient heart rate accelerations in a 40 minute period –> should be followed with further fetal assessment
Define the parts of a cervical exam:
- Dilation
- Effacement
- Station
- Dilation= estimation of the diameter of the cervical opening at the level of the internal os
- Effacement = thinning of the cervix expressed as a percentage of thinning from the perceived uneffaced state
- Station = the level of the fetal presenting part in the birth canal in relation to the ischial spines
*only do every 4 hours
Describe the different stations of a cervical exam
-3 = 3 cm above the ischial spines 0 = at the ischial spines, engaged \+3 = 3 cm below the ischial spines
Reasons for C-section
- Multiple pregnancy (too early, not in good position)
- failure of labor to progress
- concern for baby
- problems w/ placenta
- large baby
- breech presentation
- maternal infection or condition
- prior C section or uterine scar (trail of labor after C section (TOLAC) for women only w/ 1 prior low transverse c section)
- labor dystocia
Absolute contraindications to vaginal delivery
- complete placenta previa
- HSV w/ active genital lesions or prodromal symptoms
- untreated HIV
- previous classic uterine incision or extensive transfundal uterine surgery
Opioid SE when used during labor
- M- myosis
- O- out of it/ drowsy (mom and baby- hard to BF hours after birth)
- Resp. depression (mom and baby)
- P- pneumonia/ aspiration
- H- hypotension
- I- infreq. constipation/urinary retention OR ITCHY
- N- nausea
- E- emesis
What are Braxton-Hicks contractions
spontaneous/irregular uterine contractions late in pregnancy NOT ASSSOCIATED w/ cervical dilation (do not get closer together)
-false labor
Differences between false and true labor
False: irregular contractions that don’t get closer together, contrations stop w/ position change or walking, contractions sometimes get weaker, pain felt only in front usually
True: contractions at regular intervals lasting 30-70 sec, contractions continue despite movement, increase in strength steadily, pain starts in back and moves to front
What is considered premature labor
regular uterine contractions (>4-6/hrs) w/ progressive cervical changes (effacement 2-3cm and dilation 80%+) BEFORE 37 WEEKS GESTATION
*MC cause of perinatal mortality (70%)