Obstetrics Flashcards
(100 cards)
0
Q
What is the linea nigra?
A
a hyperpigmented streak appearing below the umbilicus
1
Q
What is chloasma?
A
reddish hyperpigmentation over the bridge of the nose and cheeks during pregnancy
2
Q
Chadwick’s sign?
A
bluish discoloration of vulva and vagina. Sign of pregnancy.
3
Q
Hegar’s sign?
A
softening of the cervix. Sign of pregnancy.
4
Q
Premature menopause?
A
Before age 40
5
Q
True labor and its parts
A
True labor is defined as progressive cervical dilation with uterine contractions. Effacement, the process of thinning of the cervix, occurs before and during labor. Traditionally, labor has been defined as occurring in three stages:
First stage is divided into latent (1–20 hours) characterized by milder and less frequent contractions and active (averaging 5 hours in multiparas and 8 hours in primaparas), where the cervix dilates from 4 cm to complete (10 cm) characterized by stronger, regular contractions lasting 60 seconds or more.
Second stage begins when dilation is complete and ends with the birth of the baby and averaging 20 minutes in multiparas and 50 minutes in primaparas.
Third stage is from the delivery of the baby to delivery of the placenta (up to 30 minutes is considered normal).
6
Q
At what hCG level do you expect to see a gestational sac on TVUS?
A
1500mIU/ml
7
Q
Timeline for trimesters?
A
First - 1-13 weeks
Second - 14 - 27
Third 28-term
Term- 37-42
8
Q
Factors that lead to transverse lie?
A
Predisposing factors for transverse lies include multiparity, placenta previa, hydramnios, and uterine anomalies.
9
Q
Tests to order if APH?
A
Baseline laboratory tests
include hematocrit, platelet count, fibrino
gen level, coagulation studies, blood type,
and antibody screen. Women who are Rh
negative should receive Rho(D) immune
globulin (Rhogam); a KleihauerBetke test
should be performed to determine the appro
priate dose.
10
Q
Placenta previa
- Def’n
A
-Placenta previa is a placental implantation that
overlies or is within 2 cm (0.8 inches) of the internal cervical os.
- The placenta is described as a complete previa when it covers the os and as a marginal previa when the edge lies within 2 cm of the os. When the edge is 2 to 3.5 cm (1.4 inches) from the os, the placenta may be described as low lying
11
Q
Placenta previa
- Risk factors
A
Chronic hypertension Multiparity Multiple gestations Older age Previous cesarean delivery Tobacco use Uterine curettage
12
Q
Placenta previa
-presentation
A
-Placenta previa is a common incidental
finding on second trimester ultrasonogra
phy. It is evident on approximately 4 percent
of ultrasound studies performed at 20 to
24 weeks’ gestation12 but is present at term in
only 0.4 percent of pregnancies.
- Symptomatic placenta previa usually man
ifests as vaginal bleeding in the late second or
third trimester, often after sexual intercourse.
The bleeding typically is painless unless labor
or placental abruption occurs. This initial
sentinel bleed usually is not sufficient to pro
duce hemodynamic instability or to threaten
the fetus in the absence of cervical instru
mentation or cervical digital examination
13
Q
Placenta previa
- management
A
-Women with bleeding from placenta previa
generally are admitted to the hospital for an
initial assessment.15 Because most neonatal
morbidity and mortality associated with pla
centa previa results from complications of
prematurity, the main therapeutic strategy is
to prolong pregnancy until fetal lung maturity
is achieved16 (Figure 3). Tocolytic agents may
be used safely to prolong gestation if vaginal
bleeding occurs with preterm contractions.
Corticosteroids should be administered to
women who have bleeding from placenta pre
via at 24 to 34 weeks’ estimated gestation
-Because placenta previa may resolve close
to term, it is recommended that no decision
on mode of delivery be made until after ultra
sonography at 36 weeks.25 Women whose
placental edge is 2 cm or more from the
internal os at term can expect to deliver vagi
nally unless heavy bleeding ensues.4
Women whose placenta is located 1 to 2 cm (0.4 to 0.8 inches) from the os may attempt vagi
nal delivery in a facility capable of moving
rapidly to cesarean delivery if necessary.4
Women with a nonbleeding placenta previa
may have amniocentesis at 36 to 37 weeks
to document pulmonary maturity before a
scheduled cesarean delivery
If over cesarean scar should be evaluated for accreta (U/S)
14
Q
Risk factors for placental abruption?
A
Chronic hypertension Multiparity Preeclampsia Previous abruption Short umbilical cord Sudden decompression of an overdistended uterus Thrombophilias Tobacco, cocaine, or methamphetamine use Trauma: blunt abdominal or sudden deceleration Unexplained elevated maternal alpha fetoprotein level Uterine fibroids cocaine smoking
15
Q
Placental abruption
- definition
A
Placental abruption is the separation of
the placenta from the uterine wall before
delivery. Abruption is the most common
cause of serious vaginal bleeding, occur
ring in 1 percent of pregnancies. Neonatal
death occurs in 10 to 30 percent of cases.
16
Q
Presentation of placental abruption
A
Placental abruption typically manifests as
vaginal bleeding, uterine tenderness or back
pain, and evidence of fetal distress. Preterm
labor, growth restriction, and intrauterine
fetal death also may occur. The fundus
often is tender to palpation, and pain occurs
between contractions. Bleeding may be com
pletely or partially concealed or may be
bright, dark, or intermixed with amniotic
fluid. Disseminated intravascular coagulation
may result from the release of thromboplastin
into the maternal circulation with placental
separation. This occurs in about 10 percent
of abruptions and is more common with fetal
death. A chronic form of abruption may
manifest as recurrent vaginal bleeding with
episodic pain and contractions.
17
Q
Management of abruption
A
Initial management
includes rapid stabilization of maternal car
diopulmonary status and assessment of fetal
wellbeing.
- Do not wait to get fetus out
- If fetal demise then goal is vaginal delivery
18
Q
Vasa previa - definition
A
Vasa previa is the velamentous insertion of
the umbilical cord into the membranes in
the lower uterine segment resulting in the
presence of fetal vessels between the cervix
and presenting part.
19
Q
Risk factors for vasa previa
A
In vitro fertilization Low-lying and second trimester placenta previa Marginal cord insertion Multiple gestation Succenturiate-lobed and bilobed placentas
20
Q
Presentation of vasa previa
A
Vasa previa typically manifests as onset
of hemorrhage at the time of amniotomy
or spontaneous rupture of membranes. The
hemorrhage is fetal blood, and exsanguina
tion can occur rapidly because the average
blood volume of a term fetus is approxi
mately 250 mL. Rarely, vessels are palpated
in the presenting membranes, prohibiting
artificial rupture and vaginal delivery
21
Q
Risk factors for preterm delivery?
A
Maternal characteristics Black race Interpregnancy interval of less than six months Physically strenuous or stressful work Prepregnancy body mass index ≤ 19 kg per m2 Pregnancy history Previous preterm delivery Pregnancy characteristics Bacterial vaginosis, Chlamydia infection Cocaine or heroin use History of cervical cone biopsy or loop electrosurgical excision procedure Intrauterine infection Maternal abdominal surgery Maternal medical disorders such as thyroid disease, diabetes mellitus, or hypertension Multiple gestation Nongenital tract infection (asymptomatic bacteriuria, pneumonia, appendicitis) Periodontal disease Polyhydramnios or oligohydramnios Shortened cervix (< 3.0 cm) Tobacco use Uterine anomalies Vaginal bleeding caused by placental abruption or placenta previa
22
Q
Prevention of preterm birth
A
Smoking cessation, progesterone, screening and treatment of BV in high risk women
23
Q
Effective interventions for preterm birth?
A
The three antenatal interventions that have been proven effective in premature labor are transfer to a facility with a NICU, maternal corticosteroid administration, and antibiotic
prophylaxis for group B streptococcus (GBS)
24
Assessing for true labour in preterm patients
1. Assess for rupture of membranes - sterile spec, pooling, ferning, nitrazine test, Ultrasound for oligohydramnios ,Amnioinfusion of indigo carmine (if above tests are nondiagnostic)
2. fetal fibronectin - high NPV for delivery in 14 days. The test should not be done if the patient had a vaginal examination, sexual intercourse, or endovaginal ultrasonography within the previous 24 hours.40 Other confounders to fetal fibronectin testing include vaginal bleeding, rupture of membranes, abnormal vaginal flora, and use
of vaginal lubricants or disinfectants
3. Cervical U/S - Patients with a cervical length of
at least 3.0 cm are unlikely to deliver within seven days
4. Abolishment of contractions with a single subcutaneous 0.25 mg dose of terbutaline decreased time to discharge from five to four hours when compared to observation alone
25
Management of preterm labour
Management of preterm labor consists of corticosteroids to improve fetal outcomes, antibiotics for prophylaxis of GBS infection, and limited tocolysis.
The use of tocolytics decreases the odds of delivery within 48 hours, but has not consistently been shown to improve neonatal and perinatal outcomes. Basically use for time to administer steroids and/or transfer mom. General contraindications to tocolysis include fetal distress, chorioamnionitis, and maternal instability
26
Dose of steroids for preterm birth?
betamethasone (two 12-mg intramuscular doses 24 hours apart) or dexamethasone (6 mg intramuscularly every 12 hours for four doses)
27
When to treat GBS?
For those at less than 37 weeks’ gestation who
have not yet been screened, a rectovaginal culture or rapid streptococcal test should be obtained, and prophylaxis should be started. Full antibiotic prophylaxis is indicated in patients who are culture-positive for GBS, who had GBS bacteriuria prenatally, or who had a prior newborn infected
with GBS
If GBS status is unknown at time of presentation, intrapartum chemoprophylaxis should be administered to women with duration of membrane rupture > 18 hours, or temperature > 100.4ºF (> 38ºC).
28
Treatment options for GBS?
Recommended prophylaxis
Penicillin G: initial dose of 5 million units IV, then
2.5 million units IV every four hours until delivery
-Alternative prophylaxis Ampicillin: initial dose of 2 g IV, then 1 g IV every four hours until delivery
For patients who are allergic to penicillin
Not at high risk of anaphylaxis
Cefazolin: initial dose of 2 g IV, then 1 g IV every eight hours until delivery
```
At high risk of anaphylaxis and GBS susceptible to
clindamycin (Cleocin) and erythromycin
Clindamycin: 900 mg IV every
eight hours until delivery
or
Erythromycin: 500 mg IV every
six hours until delivery
```
At high risk of anaphylaxis and GBS resistant to clindamycin or erythromycin, or GBS susceptibility unknown Vancomycin: 1 g every 12 hours until delivery
29
Indocid
| - dose, when to use, contraindications, side effects (maternal and fetal)
Indomethacin (Indocin; class: NSAIDs)
Loading dose: 50 mg rectally or 50 to 100 mg orally
Maintenance dosage: 25 to 50 mg orally every four hours for 48 hours. Total 24-hour dose should not be greater than 200 mg
NSAIDs theoretically intervene more proximally in the labor cascade than other agents; effectiveness similar to other agents
Maternal adverse effect profile is favorable
```
Other NSAIDs (sulindac [Clinoril],
ketorolac [formerly Toradol]) may be used
```
May be optimal choice for tocolysis before 32 weeks’ gestation
Contraindications: maternal renal or hepatic impairment, active peptic ulcer disease, oligohydramnios
Maternal adverse effects: nausea, heartburn
Fetal adverse effects: constriction of the ductus arteriosus (not recommended after 32 weeks’ gestation), pulmonary hypertension, reversible decrease in renal function with oligohydramnios, intraventricular hemorrhage, hyperbilirubinemia, necrotizing enterocolitis
30
MgSO4
| - dose, when to use, contraindications, side effects (maternal and fetal)
Magnesium sulfate
4- to 6-g bolus intravenously over 20 minutes, then
1 to 2 g per hour (3 g per hour
maximum)
In widespread use in the United States, although metaanalysis fails to demonstrate improvement in outcomes; comparison studies demonstrate similar effectiveness to other agents in delay of delivery
Contraindication: myasthenia gravis
Maternal adverse effects: flushing, lethargy, headache, muscle weakness, diplopia, dry mouth, pulmonary edema,cardiac arrest
Newborn adverse effects: lethargy, hypotonia, respiratory depression,demineralization with prolonged use
31
Nifedipine
| - dose, when to use, contraindications, side effects (maternal and fetal)
Nifedipine (Procardia; class: calcium channel blockers)
30-mg loading dose orally, then 10 to 20 mg every four to six hours
May offer the best outcomes of the tocolytic agents
May prolong pregnancy for seven days; delivery after 34 weeks’ gestation is also increased
Decreased incidence of neonatal respiratory distress syndrome, necrotizing enterocolitis, intraventricular hemorrhage,
and jaundice
Neonatal mortality not affected
Contraindication: maternal hypotension
Maternal adverse effects: flushing, headache, dizziness, nausea, transient hypotension
No fetal adverse effects noted
32
Terbutaline
| - dose, when to use, contraindications, side effects (maternal and fetal)
Terbutaline (formerly Brethine; class: beta mimetics)
0.25 mg subcutaneously every 20 to 30
minutes for four to six doses
Appropriate as the first-line agent
Beta mimetics may delay delivery for 48 hours, but neonatal outcomes are variable and maternal adverse effects common
Maternal contraindications: heart disease, poorly controlled diabetes mellitus, thyrotoxicosis
Maternal adverse effects: cardiac arrhythmias, pulmonary edema, myocardial ischemia, hypotension, tachycardia, hyperglycemia,
hyperinsulinemia, hypokalemia, antidiuresis, altered thyroid function, physiologic tremor, palpitations,
nervousness, nausea, vomiting, fever, hallucinations
Fetal and newborn adverse effects: tachycardia, hypoglycemia, hypocalcemia, hyperbilirubinemia, hypotension, intraventricular hemorrhage
33
What is most important risk factor for preterm labour?
Previous preterm labour. In general the risk is increased by a factor of 2.5.
34
How does progesterone prevent PTL?
The mechanisms by which progesterone prevents PTL include reduction of gap junction formation,
oxytocin antagonism, maintenance of cervical integrity and anti-inflammation.
35
When to use progesterone to prevent PTL?
The American College of Obstetricians and Gynecologists recommends that progesterone supplementation be offered to patients with a history of PTD as well as for those with serendipitously noted ultrasonic cervical length < 15 mm.
36
How to diagnose BV clincally
Amsel’s Criteria for Diagnosis of Bacterial Vaginosis
Diagnosis requires three of four findings
Homogenous, white, non-inflammatory discharge that smoothly coats the vaginal walls
Presence of clue cells on microscopic examination
pH of vaginal fluid > 4.5
Fishy odor of vaginal discharge before or after addition of 10 percent KOH
37
Treatment of BV
CDC Recommendations for Treatment of Bacterial Vaginosis in Pregnancy
Metronidazole 500 mg orally twice a day for seven days
Metronidazole 250 mg orally three times a day for seven days
Clindamycin 300 mg orally twice a day for seven days
38
Initial evaluation for patients with suspected PPROM?
Accurate dating is critical: Review dating criteria as management choices are determined by
gestational age.
• Sterile speculum examination: If rupture of membranes is suspected, digital examination should be avoided as it shortens the latency period before onset of labor and increases the risk of infection.
A sample of amniotic fluid may be obtained for fetal lung maturity evaluation if between 32 and 34 weeks
• Ultrasound evaluation: Oligohydramnios supports the diagnosis of membrane rupture. Oligohydramnios will also decrease the accuracy of fetal weight and gestational assessment. Low amniotic volume increases the likelihood of cord compression and other complications.
• Assessment of fetal lung maturity: Vaginal amniotic fluid may be tested for phosphatidyl glycerol, the presence of which indicates fetal lung maturity between 32 and 34 weeks’ gestation,
although this is not commonly done. Amniocentesis allows collection of fluid for fetal pulmonary maturity testing as well as for evaluation of infection.
• Screen for infection: Cervical cultures for sexually transmitted infections or vaginal/rectal culture for group B streptococcus may be obtained.
• Fetal monitoring: Electronic fetal heart rate and uterine contraction monitoring during initial
assessment may identify cord compression and asymptomatic contractions.
39
Antibiotic therapy for PPROM?
- advantages
- doses
At gestations between 24 and 32 weeks, treatment with antibiotics prolongs pregnancy, decreases fetal morbidity, decreases chorioamnionitis and maternal infection
Initial therapy:
Ampicillin 2 grams intravneously every six hours for 48 hours or
Erythromycin 250 mg intravenously every six hours for 48 hours
Followed by:
Amoxicillin 250 mg orally every eight hours for five days
Erythromycin base 333 mg orally every eight hours for five days
40
Gestational age and management of PPROM
->= 34
- 32-34
<32
Greater than or equal to 34 - electively induce. At 34 weeks, elective induction of labor with PPROM reduces the incidence of chorioamnionitis and neonatal sepsis.
32-34 - Thirty-two to 33 weeks, induce if fetal lungs mature based on amniocentesis or vaginal pool sample
Less than 32 - Twenty-four to 32 weeks, administer antibiotics and corticosteroids, monitor for infection and other intrauterine fetal complications. Manage expectantly till 34 if no infections or fetal compromise.
41
Problems faced by preterm fetus?
The preterm fetus is more susceptible to injury from acidosis and anoxia and therefore should be
monitored continuously. Neurologic immaturity of the fetus and effects of medications such as
betamimetics complicate fetal heart rate monitoring. Malpresentations are more common at earlier
gestations and should be anticipated.
42
Complication of third stage and preterm?
The third stage of labor may be prolonged. Retained placenta is more common than with
term pregnancies and is best managed with uterine stimulants.
43
Frequency of intermittent auscultation?
Every 15 to 30 minutes in active phase of first stage of labor; every 5 minutes in second stage of labor with pushing
44
Indications for continuous EFM?
```
Antepartum
Fetal
Abnormal umbilical artery Doppler velocimetry
Breech presentation
Intrauterine growth restriction
Multiple pregnancies
Oligohydramnios
Rh isoimmunization
```
```
Maternal
Anemia
Antepartum hemorrhage
Cardiac disease
Diabetes
Hypertension (preeclampsia or eclampsia)
Hyperthyroidism
Maternal motor vehicle collision or trauma
Morbid obesity
Renal disease
Vascular disease
```
Intrapartum
Fetal
Abnormal fetal heart rate on auscultation or admission tracing (20-minute strip)*
Meconium-stained amniotic fluid
Maternal
Hypertonic uterus
Induced or augmented labor
Intrauterine infection or chorioamnionitis
Post-term pregnancy (> 42 weeks’ gestation)
Preterm labor (< 32 weeks’ gestation)
Previous cesarean delivery
Prolonged membrane rupture > 24 hours at term
Regional analgesia, particularly after initial bolus and after top-ups (continuous electronic fetal monitoring is not required with mobile or continuous-infusion epidurals)
Vaginal bleeding in labor
45
Causes of tachyarrhythmia on EFM?
This is associated with certain maternal and fetal
| conditions, such as chorioamnionitis, fever, dehydration, and tachyarrhythmias.
46
How to classify contractions?
Contractions are classified as normal (no more than five contractions in a 10-minute period) or tachysystole (more than five contractions in a 10-minute period, averaged over a 30-minute window).
Tachysystole is qualified by the presence or
absence of decelerations, and it applies to
spontaneous and stimulated labor. The term “hyperstimulation” is no longer accepted,
and this terminology should be abandoned.
47
Causes of bradycardia on EFM?
```
Mild bradycardia (100 to 110 bpm) is associated
with post-term infants and occipitoposterior position. Rates of less than 100 bpm may be seen in fetuses with congenital heart disease or myocardial conduction defects.
```
48
What is normal variability on EFM and what is it linked too?
The FHR normally exhibits variability, with an average change of 6 to 25 bpm of the baseline
rate, and is linked to the fetal central nervous
system.
49
How do you classify variability?
absent
| minimal 25
50
Causes of decreased variability?
Sleep cycles of 20 to 40 minutes or longer
may cause a normal decrease in FHR variability,
as can certain medications, including analgesics, anesthetics, barbiturates, and magnesium sulfate. Loss of variability, accompanied by late or variable decelerations, increases the possibility of fetal acidosis if uncorrected.
51
What is the sinusoidal pattern on EFM associated with?
Sinusoidal pattern is a smooth, undulating
sine wave pattern defined by an amplitude of
10 bpm with three to five cycles per minute,
lasting at least 20 minutes. This uncommon
pattern is associated with severe fetal
anemia and hydrops, and it usually requires
rapid intervention in these settings. Similar
appearing benign tracings occasionally
occur because of “fetal thumb sucking”
or maternal narcotic administration, and
generally these will persist for less than
10 minutes.
52
What to acceleations represent?
Abrupt increases in the FHR are associated with fetal movement or stimulation and are indicative of fetal wellbeing.
53
How do you differentiate recurrent versus intermittent decels?
Periodic changes in FHR, as they relate to uterine contractions, are decelerations that are classified as recurrent if they occur with 50 percent or more
of contractions in a 20-minute period, and
intermittent if they occur with less than 50 percent of contractions.
54
Early decels
- appearance
- cause
- mirror contractions
- seldom go below 100 bpm
- benign
- head compression - normal part of labour
55
Variable decels
- appearance
- meaning.cause
Variable decelerations, as the name implies, vary in terms of shape, depth, and timing in relationship
to uterine contractions, but they are visually
apparent, abrupt decreases in FHR. The decrease in FHR is at least 15 bpm and has a duration of at least 15 seconds to less than two minutes.
Characteristics of variable
decelerations include rapid descent and
recovery, good baseline variability, and accelerations at the onset and at the end of the
contraction (i.e., “shoulders”).
When they are associated with uterine contractions, their onset, depth, and duration commonly vary with successive uterine contractions. Overall, variable decelerations are usually benign, and their physiologic basis is usually related to cord compression, with subsequent changes in peripheral vascular resistance or oxygenation. They occur especially in the second stage of labor, when cord compression
is most common.
Atypical variable decelerations may indicate fetal hypoxemia, with characteristic features that include late onset (in relation to contractions), loss of
shoulders, and slow recovery.
56
Late decel
- appearance
- meaning
Late decelerations are visually apparent, usually symmetric, and have the characteristic feature of onset of the deceleration after the onset of the uterine contraction.
The physiology behind late deceleration is uteroplacental insufficiency.
Transient late deceleration patterns may be seen with maternal hypotension or uterine hyperstimulation.
57
Prolonged decel
- timing
- causes
Prolonged decelerations last longer than two minutes, but less than 10 minutes. They may
be caused by a number of factors, including
head compression (rapid fetal descent), cord
compression, or uteroplacental insufficiency.
Management depends on the clinical picture
and presence of other FHR characteristics.
58
If there is absent variability how can you check fetal well being?
A meta-analysis showed that if there is absent or minimal variability without spontaneous accelerations, the presence of an acceleration after scalp stimulation or fetal acoustic stimulation indicates that the fetal pH is at least 7.20.
59
Areas for future fetal monitoring?
FECG analysis, Fetal pulse oximetry, The STsegment automated analysis (STAN
60
Mnemonic for interpreting FHR?
DR: Determine risk High, medium, or low risk (i.e., risk in terms of the clinical situation)
C: Contractions Rate, rhythm, frequency, duration, intensity, and resting tone
BRA: Baseline rate Bradycardia (< 110 bpm), normal (110 to 160 bpm), or tachycardia (> 160 bpm); rising baseline
V: Variability Reflects central nervous system activity: absent, minimal, moderate, or marked
A: Accelerations Spontaneous; stimulated; none
Rises from the baseline of ≥ 15 bpm, lasting ≥ 15 seconds
Preterm: ≥ 10 bpm, lasting ≥ 10 seconds
D: Decelerations Absent, early, variable, late, or prolonged
O: Overall assessment and written plan
Stoplight algorithm or National
Institute of Child Health and Human
Development categorization. Assessment includes implementing an appropriate management plan.
61
NICHD Category I: Normal
- classification
- significance
- management
Moderate baseline FHR variability, late or variable decelerations absent, accelerations present or absent, and normal baseline FHR (110 to 160 bpm)
Normal pH and fetal well-being
Continue current monitoring method (SIA or continuous EFM)
62
NICHD Category II: Indeterminate
- classification
- significance
- management
Baseline FHR changes (bradycardia [< 110 bpm] not accompanied by absent baseline variability, or
tachycardia [> 160 bpm]). Tachycardia: medication, maternal anxiety, infection, fever
Bradycardia: rupture of membranes, occipitoposterior position, post-term pregnancy, congenital anomalies
General measures
Consider expedited delivery if abnormalities persist
Change in FHR variability (absent and not accompanied by decelerations; minimal; or marked)
Medications; sleep cycle; change in monitoring technique; possible fetal hypoxia or acidemia
General measures
Change monitoring method (internal monitoring if doing continuous EFM, or EFM if doing SIA)
Consider expedited delivery if
abnormalities persist
No FHR accelerations after fetal stimulation
Possible fetal hypoxia or acidemia
General measures
Discontinue oxytocin (Pitocin)
Consider expedited delivery if
abnormalities persist
FHR decelerations without absent variability
Variable: cord entrapment or prolapse
General measures
Amnioinfusion (for recurrent decelerations)
FHR decelerations without absent variability
Late: possible uteroplacental insufficiency; epidural hypotension; tachysystole
General measures
Discontinue oxytocin
Consider expedited delivery if abnormalities persist
63
NICHD Category III: Abnormal
- classification
- significance
- management
Absent baseline FHR variability with recurrent decelerations (variable or late) and/or bradycardia
OR
Sinusoidal FHR pattern
Uteroplacental insufficiency; fetal hypoxia or acidemia
General measures
Discontinue oxytocin
Expedite delivery
64
General measures for abnormal EFM?
1. Change maternal position
2. Assess maternal vital signs (temperature,
blood pressure, pulse)
3. Discontinue oxytocin (Pitocin) infusion, if in use
4. Initiate oxygen at 6 to 10 L per minute
5. Perform a vaginal examination (check for cord prolapse, rapid descent of the head, or vaginal bleeding suggestive of placental abruption)
6. Give intravenous fluids if not already administered; consider bolus
7. Assess fetal pH (fetal scalp stimulation, scalp pH, or acoustic stimulation)
8. Give amnioinfusion for recurrent, moderate to severe variable decelerations
9. Consider need for expedited delivery (operative vaginal delivery or cesarean delivery)
65
Reasons for labour dystocia
Power - contractions are inadequate
Passage - abnormal pelvic anatomy, cephalopelvic disprotion
Passenger - fetal malposition, macrosomia, fetal anomalies
66
Definitions of Labour dystocia by state
Traditional Definitions of A bnormal L abor
Stage of labor
Latent
Nulliparous > 20 hours NA -protracted
Multiparous > 14 hours NA
```
First stage
Nulliparous < 1 cm per hour dilation ≥ 2 hours of active labor
without cervical change
Multiparous < 1.2 to 1.5 cm per hour
dilation - protracted
≥ 2 hours of active labor - arrested
without cervical change
```
```
Second stage
Nulliparous or multiparous
With no regional anesthesia:
> 2 hours duration
or
< 1 cm per hour descent
With regional anesthesia:
> 3 hours duration
```
Arrested - No descent after 1 hour of pushing
67
How to prevent labour dystocia in nullip?
The incidence of dysfunctional labor in
nulliparous women may be decreased by four methods: (1) provision of labor support; (2) avoidance of hospital admission in latent stage of labor; (3) avoidance of elective induction with an unripe cervix; and (4) cautious use of epidural analgesia.
68
Recommendations regarding labour dystocia?
Amniotomy in the first stage of labor results in shorter labor, but it also may be associated with variable fetal heart rate decelerations; therefore, it should be reserved for slowly progressing labors. A
High-dose oxytocin regimens result in shorter labors than low-dose regimens without adverse effects for the fetus. A
Women who receive continuous labor support from a labor support companion use less analgesia, have lower rates of operative vaginal and cesarean delivery, and are less likely to report dissatisfaction with their childbirth experiences.
A
Epidural analgesia is associated with a prolongation of the second stage of labor and an increase in oxytocin use and operative vaginal delivery.
A
It is important to follow systematic protocols for diagnosing labor, assessing its progress, and using oxytocin. Audit and feedback regarding operative deliveries has been associated with lower institutional cesarean delivery rates. C
69
Contraindications for vacuum assisted delivery
Cephalopelvic disproportion
Fetal head not engaged
Gestational age less than 34 weeks
Known fetal conditions that affect bone mineralization or bleeding disorder
Noncephalic or facial presentation
70
Indications for vacuum assisted delivery?
Prolonged second stage of labor, defined as:
A lack of continuing progress for two hours without regional anesthetic, or three hours with regional anesthetic in nulliparous women
or
A lack of continuing progress for one hour without regional anesthetic, or two hours with regional anesthetic in multiparous women
Nonreassuring fetal heart tones or other suspicion of immediate or potential fetal compromise
Shortening of the second stage of labor for maternal benefit (e.g., maternal exhaustion)
71
Risks of using vacuum?
Maternal - increased fourth and third degree tears, less than forceps though
Fetal - cephalohematoma, retinal hemmorrhage, subgaleal hematoma, intracranial hemmorrhage
72
ABCDEFGHIJ of vaccuum assisted delivery?
A - Address patient, analgesia, ask for help
B - empty bladder to prevent injury
C - Cervical dilatation
D - determine position of fetal head, think shoulder dystocia
E - check equipment
F - Apply 3cm in front of posterior Fontanelle over sagittal suture
Applied at Flexion point
G - gentle traction with contractions at right angles to plane of cup
H - Halt if:
- 3 pop offs
- 3 pulls with no descent
- 20 minutes with no delivery
- do not pull between contractions
I - evaluate need for Incision (episiotomy)
J - remove when Jaw reachable
73
ABCDEFGHIJ for forceps delivery?
A - Address patient, analgesia, ask for help
B - empty bladder to prevent injury
C - Cervical dilatation
D - determine position of fetal head, think shoulder dystocia
E - check equipment
F - Forceps ready
Position for safety
P - posterior fontanelle midway between shanks, 1cm above plane of shanks
F- fenestrations admit no more than one fingertip
S - sutures - lamboidal above, and equidistant from upper surface of each blade, sagittal midline
G - gentle traction - Pajot's manuveur - following plane of pelvis
H - Handle elevated vertically, to follow J-shaped pelvic curve
I - evaluate need for Incision (episiotomy)
J - remove when Jaw reachable
74
Factors associated with third and fourth degree tears
Anesthesia, episiotomy (midline>mediolaeral), nulliparous, increased birth weight, stirrups, increased second stage of labour, OT or OP, operative vaginal delivery, patient age <21 years, oxytocin use
75
Preventative strategies for lacerations?
Warm packs during second stage, lateral position, avoid episiotomy, allow time for perineal thinning, avoid operative delivery, perineal massage in nulliparous starting at 36 weeks
76
```
Definitions:
Miscarriage or spontaneous abortion
Threatened abortion
Inevitable abortion
Incomplete
```
Spontaneous abortion - involuntary loss during the first 20 weeks
Threatened - uterine bleeding closed cervix; no products have passed
Inevitable - cervix dilated, products not passed
Incomplete - some but not all products have passed
77
Discriminatory criteria when viewing embryo on us for a normal pregnancy?
(vaginal us)
1. Seeing a gestational sac when bHCG is between 1500-2000mIU per ml
2. Yolk sac present when gestational sac greater than 10mm in diameter
3. Cardiac activity when the embryo exceeds 5mm of length.
78
When to use medical vs surgical vs expectant management for ectopic pregnancy?
Expectant
Minimal pain or bleeding.
No embryonic heartbeat.
Patient reliable for follow up.
Declining bHCG and starting bHCG of less than 1000.
No embryonic heartbeat.
Ectopic or adnexal mass less than 3cm or not detected.
Medical management with methotrexate
Stabe vitals and few sypmtoms
Unruptured ectopic pregnancy
No contraindications to methotrexate (e.g. normal liver enzymes, complete blood count and platelet count)
Absence of embryonic cardiac activity
Ectopic mass of 3.5 cm or less
Starting bHCG of 5000 or less
Dosage: Single intramuscular dose of 1mg per kg or 50 mg per m2.
Follow up: Repeat bHCG of fourth and seventh days and weekly until undetectable - usually requires several weeks.
Expected bHCG changes: Initial slight increase, then 15% decrease between days 4 and 7; if not, repeat dose or move to surgery.
Special consideration: Prompt surgical intervention if patient does not respond to treatment
Surgical
Tubal rupture or hemoperitoneum
Unstable vital signs
Uncertain diagnosis
Advanced ectopic pregnancy (e.g. high bHCG, large mass, cardiac activity)
Unreliable patient or unavailable for follow up
Contraindications to observation or methotrexate
79
Differential for first trimester bleeding?
```
Pregnancy related
Ectopic
Spontaneous abortion
Threatened abortion
Subchorionic hemorrhage
```
```
Non-obstetric
Trauma - tears (vaginal, cervical)
Cervical ectropion
Cervical polyp
Cervisitis
Cervical cancer
vaginitis
```
hemmorrhoids
80
Name and define the four categories of hypertension disorders in pregnancy
1. Chronic hypertension is defined as a blood
pressure measurement of 140/90 mm Hg or
more on two occasions before 20 weeks of gestationor persisting beyond 12 weeks postpartum.
2. Gestational hypertension has replaced the
term pregnancy-induced hypertension to
describe women who develop hypertension
without proteinuria after 20 weeks of
gestation. 50% diagnosed between 24-35 weeks go on to develop preeclampsia.
3. Preeclampsia is a multiorgan disease process
of unknown etiology characterized by the
development of hypertension and proteinuria
after 20 weeks of gestation.
4. Preeclampsia superimposed on chronic hypertension
81
Risk factors for preeclampsia?
```
Antiphospholipid antibody syndrome
Chronic hypertension
Chronic renal disease
Elevated body mass index
Maternal age older than 40 years
Multiple gestation
Nulliparity
Preeclampsia in a previous pregnancy
(particularly if severe or before
32 weeks of gestation)
Pregestational diabetes mellitus
```
82
Prevention of preeclampsia?
Prevention through routine supplementation with calcium,magnesium, omega-3 fatty acids, or antioxidantvitamins is ineffective. Calcium supplementation reduces the risk of developing preeclampsia in high-risk women and those with low dietary calcium.
Low-dose aspirin (75 to 81 mg per day) is effective
for women at increased risk of preeclampsia. Treating 69 women prevents one case of preeclampsia; treating 227 women prevents one fetal death. For women at highest risk fromprevious severe preeclampsia, diabetes, chronic hypertension, or renal or autoimmune disease, only 18 need to be treated with low-dose aspirin to prevent one case of preeclampsia
83
Diagnostic criteria for preeclamsia?
Diagnostic criteria for preeclampsia
are systolic blood pressure of 140 mm Hg or more or a diastolic blood pressure of 90 mm Hg or more on two occasions at least six hours apart.
The diagnostic threshold for proteinuria is 300 mg in
a 24-hour urine specimen. A 24-hour determination is most accurate because urine dipsticks can be affected by variable excretion, maternal dehydration, and bacteriuria.
A random urine protein/creatinine ratio of less
than 0.21 indicates that significant proteinuria is unlikely with a negative predictive value of 83 percent; however, confirmatory 24-hour urine protein determination is recommended.
84
Diagnostic criteria for severe preeclampsia?
Blood pressure ≥ 160 mm Hg systolic or 110 mm Hg diastolic on two occasions at least six hours apart during bed rest
Proteinuria ≥ 5 g in a 24-hour urine specimen or 3+ or greater on two random urine specimens collected at least four hours apart
```
Any of the following associated signs and symptoms:
Cerebral or visual disturbances -scotoma, severe headache, scotomas
Epigastric or right upper quadrant pain
Fetal growth restriction
Impaired liver function
Oliguria < 500 mL in 24 hours
Pulmonary edema
Thrombocytopenia
```
A creatinine greater than 80 in a pregnant woman is abnormal secondary their increased GFR.
85
What is the definition of birth?
The complete expulsion or extraction from the mother of a fetus after 20 weeks' gestation. As described above, in the absence of accurate dating criteria, fetuses weighing <500 g are usually not considered as births, but rather are termed abortuses for purposes of vital statistics.
86
What is the defination of birth rate?
The number of live births per 1000 population
87
What is the definition of early neonatal death?
Death of a liveborn neonate during the first 7 days after birth
88
What is the definition of late neonatal death?
Death after 7 days but before 29 days
89
What is the definition of low birthweight?
What is the definition of very low birthweight?
What is the definintion of extremely low birthweight?
A newborn whose weight is < 2500 g
A newborn whose weight is < 1500 g.
A newborn whose weight is <1000 g.
90
What is the definition of term neonate?
A neonate born anytime after 37 completed weeks of gestation and up until 42 completed weeks of gestation (260 to 294 days).
91
When will a woman first feel fetal movements?
Maternal perception of fetal movement may depend on factors such as parity and habitus. In general, after a first successful pregnancy, a woman may first perceive fetal movements between 16 and 18 weeks. A primigravida may not appreciate fetal movements until approximately 2 weeks later (18 to 20 weeks). At approximately 20 weeks, depending on maternal habitus, an examiner can begin to detect fetal movements.
92
What is the pattern of hCG in pregnancy?
Trophoblast cells produce hCG in amounts that increase exponentially following implantation. With a sensitive test, the hormone can be detected in maternal plasma or urine by 8 to 9 days after ovulation. The doubling time of plasma hCG concentration is 1.4 to 2.0 days. Serum hCG levels increase from the day of implantation and reach peak levels at 60 to 70 days. Thereafter, the concentration declines slowly until a nadir is reached at about 16 weeks.
93
What are some contraindications to induction?
•• placenta or vasa previa or cord presentation
•• abnormal fetal lie or presentation (e.g. transverse lie
or footling breech)
•• prior classical or inverted T uterine incision
•• significant prior uterine surgery (e.g. full thickness
myomectomy)
•• active genital herpes
•• pelvic structural deformities
•• invasive cervical carcinoma
•• previous uterine rupture
94
What are some indications for induction?
High Priority
•• Preeclampsia ≥ 37 weeks
•• Significant maternal disease not responding to treatment
•• Significant but stable antepartum hemorrhage
•• Chorioamnionitis
•• Suspected fetal compromise
•• Term pre-labour rupture of membranes with maternal GBS colonization
Other Indications
•• Postdates (> 41+0 weeks) or post-term
(> 42+0 weeks) pregnancy
•• Uncomplicated twin pregnancy ≥ 38 weeks
•• Diabetes mellitus (glucose control may dictate
urgency)
•• Alloimmune disease at or near term
•• Intrauterine growth restriction
•• Oligohydramnios
•• Gestational hypertension ≥ 38 weeks
•• Intrauterine fetal death
•• PROM at or near term, GBS negative
•• Logistical problems (history of rapid labour, distance to hospital)
•• Intrauterine death in a prior pregnancy (Induction may
be performed to alleviate parental anxiety, but there is no known medical or outcome advantage for mother or baby.)
Unacceptable Indications
•• Care provider or patient convenience
•• Suspected fetal macrosomia (estimated fetal weight
> 4000 gm) in a non-diabetic women is an
unacceptable indication because there is no reduction
in the incidence of shoulder dystocia but twice the risk
of CS.
95
What are some risks of inductions?
•• failure to achieve labour
•• Caesarean section
•• operative vaginal delivery
•• tachysystole with or without FHR changes
•• chorioamnionitis
•• cord prolapse with ARM
•• inadvertent delivery of preterm infant in the case of
inadequate dating
•• Uterine rupture in scarred and unscarred uteri
96
How do you break down the Bishop Score?
Modified Bishop Scoring System Score
Factor 0 1 2
Dilatation, cm 0 1–2 3–4
Effacement, % 0–30 40–50 60–70
Length, cm > 3 1–3 < 1
Consistency Firm Medium Soft
Position Posterior Mid Anterior
Station Sp −3 or above Sp −2 Sp −1 or 0
97
What is a favourable Bishop score?
A favourable preinduction Bishop score of > 6 is predictive of a successful vaginal delivery.
98
What is the SOGC's stance on when to induce?
Women should be offered induction of labour between 41+0 and 42+0 weeks as this intervention may reduce perinatal mortality and meconium aspiration syndrome without increasing the Caesarean section rate. (I-A)
Women who chose to delay induction
> 41+0 weeks should undergo twice-weekly
assessment for fetal well-being. (I-A)
Sept 2013
99
How do you mechanically induce the cervix with a Foley balloon?
For a single balloon catheter, a no. 18 Foley is introduced
under sterile technique into the intracervical canal past the internal os. The bulb is then inflated with 30 to 60 cc of water. The catheter is left in place until either it falls out spontaneously or 24 hours have elapsed. Some practitioners apply a small degree of traction on the
catheter by taping it to the inside of the leg.46 Low-lying
placenta is an absolute contraindication to the use of a Foley catheter. Relative contraindications to its use include antepartum hemorrhage, rupture of membranes, and evidence of lower tract genital infection.
