General OB Flashcards
Incidence of macrosomia?
1.5%
Risk of shoulder dystocia
- W/o macrosomia
- W/ macrosomia
- W/ macrosomia & DM
- 1.5%
- 15%
- 25%
Risk of brachial plexus injury
- W/o macrosomia
- W/ macrosomia
- 0.1%
2. 5%
Risk factors for macrosomia (6)
- h/o macrosomia
- excessive weight gain
- maternal obesity
- gest age > 40 wks
- pos 1hr GTT and neg 3 hr GTT
- DM
When is fetal macrosomia an indication for IOL
> 5000g, 4500g if diabetic
Medication to consider for shoulder dystocia
- onset
- duration
- SE
Nitroglycerine (50-100mcg)
onset- 30-90 sec
lasts 2-3 mins
SE: mild hypotension
Maneuvers to reduce shoulder dystocia
- Suprapubic pressure
- McRoberts maneuver
- Deliver Posterior arm
- Rubin Maneuver
- Woods corkscrew maneuver
- Episiotomy (only to make room for hand)
- Intentional clavicular fracture
- Zavanelli maneuver
- Symphysiotomy
- Laparotomy
Rubin Maneuver
- pressure on posterior of the most accessible shoulder
- rotate fetus <180 to dis-impact the shoulder from the symphysis
- decreases the bis-acromial diameter
Woods Corkscew maneuver
- pressure on the front of the posterior shoulder
- rotate fetus <180
- increases the bis-acromial diameter
Zavaneli Maneuver
cephalic replacement reverse cardinal movements of labor do c-section (consider tocolytic) LAST RESORT
Intentional Clavicular Fracture
Anterior fracture
Risks of Clavicular Fracture
Penumothrox
Hemothorax
Subclavian vessel injury
Brachial plexus injury
Erb’s Palsy
C5-C6 Arm hangs at side medially rotated Forearm extended & pronated Wrist flexed Grasp reflex intact (waiter's tip)
Klumpke’s Palsy
Flaccid Arm C8-T1 Hand & wrist paralysis arm hangs flaccidly at side Grasp reflex lost
Cardinal movements
- Engagement
- Descent
- Flexion
- Internal rotation
- Extension
- External rotation
- Expulsion
NPV for NST, CST, BPP, modified BPP, umbilical artery doppler
> 99.8%
PPV for NST
10%
Contraindications for ECV
- Multiple gestation
- IUGR
- Indication for elective c/s
- Placenta previa
- Maternal cardiac disease
- Gestational Hypertension
- Previous classical c/s
- Utero-placental insufficiency
- Congenital uterine malformations
- Oligohydramnios
- Major fetal anomaly
- NRFHT
- PROM
- Unexplained uterine bleeding
Ideal time for ECV
37 weeks
Vaginal Breech Delivery Prerequisites
- Call for help (extra OB, pediatrician, nurse and anethesiologist)
- Have Piper forceps in delivery room
- Empty bladder & rectum
- Functional IV line
- Oxygen for mother
Vaginal Breech Delivery Motions
- Hands off, only apply rotational force to achieve backup position
- Deliver legs with Pinaud’s maneuver (pressure on popliteal fossa)
- Wrap body in towel
- Lovset’s maneuver for delivery of arms
(slide hand from back over shoulder, onto anterior surface of humerus, place pressure in cubital fossa & sweep arm over over chest to the side and out of the vagina - Wrap arms in body in towel
- Make sure the back rotates anteriorly (persistent back down=disaster for trapped head)
- Delivery of head
Delivery of Head in Vaginal Breech Delivery
- Suprapubic pressure (promote flexion)
- Bracht Maneuver (only after back of neck firmly tucked under symphysis pubis)-baby’s body is held against pubic symphysis
- Mauriceau-Smellie-Veit Maneuver
- Piper forceps for after-coming head
- Consider possible need for Duhrssen incision (2,6, and 10 o’clock)
Max amount of lidocaine w/ and w/o epinepherine
w/ epi: 7mg/kg 0.5% (max 60cc)
w/o epi: 4mg/kg 0.5% w/o epi (max 30cc)
Side Effects of Epinepherine in order of increasing toxicity
Metallic taste in mouth Perioral numbness Tinnitis Slurred speech & blurred vision Altered consciousness Convulsions Cardiac arrhythmias Cardiac arrest
During an emergency c/s which layers must be infiltrated with local anesthesia?
Skin
Parietal peritoneum
Visceral peritoneum
Signs of Uterine Rupture
- Most consistent (70%)- abrupt FHR abnormality
- Abrupt change in uterine ctx pattern
- loss of station
- vaginal bleeding (not consistent)
- pelvic/abdominal pain (not consistent)
Peri-mortem C/S
- within what time period
- relationship to CPR
- within 4 minutes, (survival diminishes after 5 min)
- CPR should not be initiated in lieu of immediate delivery
(not sufficiently effective in maintaining CO, delays optimal window for delivery, compressions less effective w/ lg ut)
Contraindications to TOLAC
- Previous uterine rupture
- previous classical or T-incision
- Extensive transfundal surgery
Candidates for TOLAC
- 1 or 2 previous LTCD
- Previous low vertical CD
- Previous CD w/ unknown scar unless there is strong suspicion of a classical CD
- Twin gestation
Requirements for TOLAC
- Adequate pelvis
- Continuous EFM recommended
- Appropriately trained MD available throughout labor
- Hospital/facility support for emergency c/d
Rupture risk during TOLAC for
- Background risk
- Undocumented scar
- Twins
- Previous lower segment rupture
- Previous upper segment rupture
- Classical CD
- Induction w/ PGE1
- PG induction for 2nd TM loss
Rupture risk during TOLAC for
- Background risk (1%)
- Undocumented scar (1%)
- Twins (1%)
- Previous lower segment rupture (6%)
- Previous upper segment rupture (32%)
- Classical CD (10%)
- Induction w/ PGE1 (15%)
- PG induction for 2nd TM loss (1%)
VBAC success rates
- previous CD for CPD
- previous CD not for CPD
- previous CD for CPD (66%)
2. previous CD not for CPD (75%)
Risks to infant from Parvovirus
1st TM-Spontaneous Abortion
2nd TM- Hydrops, anemia, heart failure, IUFD
How do you diagnose B19?
ELISA for IgG & IgM or
PCR (more sensitive)
Mother tests positive for Parvovirus. How do you follow?
Serial weekly u/s for fetal well-being and to r/o hydrops for 2 moths after exposure/infection
-PUBS looking for fetal anemia, transfusion if hydrops is present
Maternal effects from Varicella
- pneumonia (20%), more common in 3rd TM, mortality 5%, tx w/ Acyclovir IV, ICU admit
- Encephalitis-rare
- Shingles
Fetal effects from Varicella
- Spontaneous abortion
- IUFD
- Varicella embryopathy (risk 13-20 wks–> 2%)
Neonatal effect of Varicella
increased mortality if maternal infection is <5 days from delivery (no passive maternal IgG)
Varicella Post-exposure prophylaxis
VariZIG - 60-80% effective in preventing infx
Varicella vaccine
2 doses SQ 4-8 wks apart
Live attenuated, contraindicated in pregnancy
Not teratogenic, not indicated for termination
Defer pregnancy for 3 months post vaccination
Incidence of Listeria in pregnant patients
13x greater for pregnant women
Symptoms of Listeria
mild GI /flu-like sx (mayalgia, N&V, diairrhea)
Listeria: Fetal effects
fetal loss
PTL
Listeria: Neonatal effects
sepsis
meningitis
death
Listeria: dx
Blood cultures (not stool)
Management of pregnant pt who consumes recalled or implicated food product
- Asymptomatic- no testing, no tx, observe for sx for 2 months
- Mildly symptomatic- no fever
- manage as for asymptomatic
- send blood cx, only tx if cx+
- Febrile-w/ or w/o symptoms-test and tx simultaneously
Tx of Listeria
-high dose IV ampicillin (at least 6gm/day) for 14d, may add gentamicin
(Bactrim w/ PCN allergy)
Hepatitis B in pregnancy
- Incidence
- Risk of vertical transmission
- Breast feeding recommendations?
- Prevention
Hepatitis B in pregnancy
- Incidence-40%
- Risk of vertical transmission- HBsAg+ (20%), HBsAg & HBeAg+ (90%)
- Breast feeding recommendations? Ok in preg but needs vaccine 0, 1 , 6 m)
- Prevention- Vaccine and HBIG w/in 24 hrs of exposure
Significance of HBcAg and HBeAg
HBcAg-found in hepatocyts, positive w/ natural but not vaccine based immunity
HBeAg- High infectivity, active replication, cirrhosis and liver cancer association
Risk of Vertical Transmission of Hepatitis B:
- 1st TM vs. 2nd TM
- How do majority of transmission occur?
- Risk of transmission during amniocentesis? Hi/Lo?
- Which method of delivery has lower risk of transmission?
Risk of Vertical Transmission:
- 1st TM-10% vs. 2nd TM-90%
- How do majority of transmission occur? during delivery
- Risk of transmission during amniocentesis? Hi/Lo?
- Which method of delivery has lower risk of transmission? Transmission rate not affected by mode of delivery.
C-section Abx prophylaxis for c-section
Cefazolin (Ancef) 1gm
Cefazolin 2gm IV if BMI>30 or >100kg
Clindamycin 900mg w/ aminoglycoside (eg. gentamycin)
Latency Abx
Ampicillin 2gm q6 hr x 48 hr Erythromycin 250 mg q6 x 48 hr then Amoxicillin 250mg q 8 hr x 5 d Erythromycin 333g q8 hr x 5 d
Incidence of GBS pos cx in population
20%
- How long is GBS cx valid for?
2. When should routine cx be taken?
- 5 wks
2. 35-37 wks
What affect does GBS prophylaxis have on early GBS infx?
80% reduction in early onset GBS
GBS prophylaxis
-Pen G 5 mil u, then 2.5 mil u q4 hr until delivery or
-Amp 2gm bolus then 1gm IV q4 hr to delivery
PCN Allergy:
Low risk: Cefazolin 2gm iv then 1gm q8 hr
High risk: Clindamycin 900 mg Q8 hr (if susceptible to both clinda and erythromycin) or
Vancomycin 1gm IV q12 hr (if no sus testing/ resistant to erythro)
Clinical features of CMV
- Chorioretinitis
- Hepatosplenomegaly
- IUGR
- Fetal hydrops
- Echogenic bowel
- Congenital deafness
- Microcephaly
- Ventriculomegaly
CMV Vertical Transmission
More common in 3rd TM but more severe in 1TM
Causes of Recurrent Pregnancy Loss
Uterine anomalies Genetic Luteal phase deficiency Infection (TORCH, B19, Syphilis) Immune d/o (APLA, alloimmune)
Which congenital uterine abnormality carries the worse prognosis?
Septate
W/up for recurrent preg loss
- Hx- family, PMH, exposure
- Examination (placenta, autopsy, HSG/SHG)
- Tests: CBC, Utox, TORCH, RPR, AclAb, Lupus anticoag, KB, Karyotype, TSH, HBA1c
Incidence of recurrent preg loss?
1-2%
Definition of recurrent pregnancy loss?
3 or more spontaneous pregnancy losses
testing should begin after 2, risk of another is just as high as after 3rd
Baseline incidence of SAB?
20% (40% of these are genetically abnormal)
Isoimmunization w/up
-If ab screen positive-> titer =/> 16-Doppler MCA to assess anemia (replaces amnio to measure delta OD 450)
Prevention of isoimmunization
- 50 micrograms for 1TM bleeding/loss
- 300 micrograms
- covers up to 15 ml fetal blood cell transfusion (30ml whole blood)
How much blood does normal dose of Rho GAM cover?
-up to 15 ml of fetal blood cell transfusion (30ml or whole blood)
How long is regular dose of Rho GAM effective?
10-12 weeks
What is the name of the test used to determine dose of RhoGAM necessary postpartum?
Kleihauer-Betke
Minor Antigens and effects
Kell =Kills (IgG)
Duffy = Dies (IgG)
Lewis = Lives (IgM)
Weak Rh+ treatment
treat as Rh +
- Sickle Cell Heredity
2. Sickle Cell Trait Heredity
- Autosomal Recessive, Homozygous (Hb AS)
2. Heterozygous (Hb AS)
Incidence of Sickle Cell Gene in African Americans
1:12 (AS)
Pathophysiology of Sickle Cell
Decreased pO2-> sickling -> microvascular obstruction-> decreased perfusion & organ damage (eg. auto splenectomy-> inc infx risk & acute chest syndrome)
Sx of Acute Chest Syndrome
- Pulmonary infiltrate (vaso-occulsive dz)
- Fever
- Hypoxemia
- Acidosis
Dx of Sickle Cell Disease on Hgb Electrophoresis
SS Dz: virtually all Hb is HbS w/ minimal HbA2/HbF
SS Tr: Higher % if HbA & asymptomatic