Obstetrics Flashcards
This deck covers Chapters 178-182 in Rosens, compromising all of obstetrics.
What is the mechanism of action of methotrexate (MTX)?
What are the 6 requirements for MTX in ectopic pregnancy?
What are 3 contraindications to using MTX?
Mechanism
- Folic acid inhibitor which blocks nucleic acid synthesis
Indications
- Hemodynamically stable
- No fetal heart tones
- No evidence of rupture
- Small (< 3.5 cm)
- β-hCG < 5,000
- Good follow-up (reliable)
Contraindications
- Leukopenia
- Thrombocytopenia
- Hepatic disease
- Renal disease
What are the 6 steps in the emergency management of umbilical cord prolapse?
- Elevate the presenting part off the cord
- Place mom in knee-to-chest position
* Alternatively: On all fours - Infuse 500 mL NS into bladder & clamp Foley
* This elevates the presenting part - DO NOT reduce the cord
* Unless no surgical alternative and delivery is happening no matter what - Cover cord with wet gauze + minimize manipulation
- Facilitate crash C-section
Outline the management of severe preeclampsia and eclampsia
- Obstetrics consult
- BP control <160/105
* Labetalol 20 mg IV
* Hydralazine 10 mg IV - Magnesium 4g IV over 15 min then 2 g/hr
* Stop if:
* Areflexia
* RR depression
* UO <25 cc/hr
* Contraindications
* Hypocalcemia
* Renal failure
* Myasthenia gravis
* Reverse with Calcium gluconate
List 6 risk factors for miscarriage
- Extremes of age
- Previous miscarriage
- Smoking
- Cocaine
- Infections
- Chromosomal abnormalities
- Fibroids
- Antiphospholipid Syndrome
- Uterine scarring
- Hx of vaginal bleeding
- Incompetent cervix
Outline your management of PPH
Tone
- Uterine massage
- Oxytocin 20-40 U in 1L NS over 1h (or 10 U IM)
- Methylergonovine 0.2 mg IM Q2-4H
- Carboprost (Hemabate) 0.25 mg IM Q15min x8
- Misoprostol (Cytotec) 1 mg PR
Tissue
- Ensure no tissue in cervix; patient may need D&C
Trauma
- Look for lacerations
Thrombin
- Treat coagulopathies (consider TXA, Vit K, FFP etc.)
Other
- Uterine packing (can soak gauze in thrombin)
- Pelvic vessel embolization (speak to IR)
- Hysterectomy
List 6 warning signs for the development of frank eclampsia
- Headache
- Nausea + vomiting
- Visual disturbances
- MAP > 160
- Elevated AST, LDH, Uric acid
- Hyperreflexia
Your department’s US is broken. Who can get follow up in 24-48 hours for a T1 bleed?
Indications for U/S within 48 hours (not in ED)
- Minimal pain
- Minimal bleeding
- Reliable (will RTED if worse)
- No strong risk factors for ectopic
- No big signs of ectopic (unilateral pain, tenderness, mass)
What is the most sensitive way to diagnose placental abruption?
Fetal monitoring
How do you diagnose PE in pregnancy?
YEARS Algorithm
- Clinical symptoms of DVT?
- PE most likely?
- Hemoptysis?
If none of above, D-dimer <1000 = negative
If one of above, D-dimer <500 = negative
If any above and D-dimer >500 = CTPE
Results: CT pulmonary angiography was avoided in 65% of patients who began the study in the first trimester and in 32% who began the study in the third trimester.
What age of gestation do you consider tocolytics?
Why do we use tocolytics?
What are contraindications to tocolytics?
What agents are commonly used as tocolytics?
Indication
- Women 24-32 weeks of gestation
- Allows delay of labour to mature lungs more
Contraindications
- Chorioamnionitis
- Placental abruption (severe)
- Fetal demise
- Severe uncontrolled HTN/pre-eclampsia (severe)
- >34 weeks
Tocolytics
- Indomethacin (24-32 weeks)
- After 32 weeks, concern about PDA closure
- Nifedipine (32-34 weeks)
- If any contraindication to indomethacin as well
- Magnesium
Why would a pulmonary embolism or DVT be difficult to diagnose in pregnancy?
Challenges with PE diagnosis
- Increased baseline RR (physiologic)
- Dyspnea of pregnancy (physiologic)
- Increased baseline HR (physiologic)
- Radiation concerns (PE only)
- D-dimer will be elevated
- Venous pooling in LE = pain + swelling (physiologic)
Define:
- Gestational HTN
- Chronic HTN
- Preeclampsia
- Eclampsia
Gestational HTN
- BP 140/90 >20 weeks that is new
Chronic HTN
- BP 140/90 <20 weeks or pre-existing HTN
Pre-eclampsia
- HTN 140/90 + Proteinuria (0.3 g/24h)
- Severe defined as any end-organ dysfunction
Eclampsia
- Preeclampsia and seizure or coma
What is the criteria for ultrasound +IUP?
- Bladder/Uterine Juxtaposition
- Myometrial Mantle >8 mm
- Fetal Pole or Yolk sac
- Gestational Sac
Describe Leopold’s maneuvers
1st Leopold Maneuver
- What fetal part occupies the fundus
2nd Leopold Maneuver
- The position of the fetal back
3rd Leopold Maneuver
- What fetal part lies over the pelvic inlet
4th Leopold Maneuver
- Position of the cephalic prominence
What is the earliest hCG can be detected in pregnancy?
When does it peak? Give a value.
- hCG detected at 6 – 8 days after conception
- hCG peaks at 7 – 10 weeks of pregnancy
- Mean value 50,000 mIU/mL (20,000 – 200,000)
How can you estimate gestational age using your exam?
Umbilicus is 20 weeks
Every cm above it is + 1 week
Outline your management of shoulder dystocia
HELPER
- Call for Help
- Empty the bladder/Episiotomy
- Lift legs/Flex hips (McRoberts)
- Pubic (suprapubic) pressure
- Enter the vag: Woods’ Corkscrew
- Reach for posterior shoulder
- Break clavicle
- Push baby into uterus for crash C-section
- Cut pubic symphysis
Concerning transvaginal ultrasonography (TVUS):
A. What is the discriminatory zone?
B. At what β-hCG should you see a yolk sac?
C. At what β-hCG should you see a fetal pole?
D. At what β-hCG should you see fetal heart activity?
Discriminatory zone
- BhCG level when you can reliably see a gestational sac
- TVUS : BhCG 1500
- TAUS: BhCG 6000
Yolk Sac
- 6 weeks and BhCG 2500
Fetal Pole
- 7 weeks and BhCG 5000
Fetal Heart Activity
- 6-7 weeks and BhCG 7000
List 8 physiologic changes in pregnancy
Cardiovascular
- Increased CO
- Increased blood volume
- Increased resting HR
- Decreased SVR / BP
- Increased venous pooling in LE
Pulmonary
- Increased RR (decreased PCO2)
- Decreased FRC
- Decreased VT
- Increased minute ventilation
GI
- Decreased gastric motility (aspiration)
- Decreased LES tone (aspiration)
- Increased ALP
Renal
- Increased RBF
- Increased GFR
- Decreased BUN/Cr
MSK
- Increased ligament laxity
Hematologic
- Increased WBC
- Increased HgB
- Decreased HCT
- Hypercoagulable state
What are the 4 stages of labor?
Stage 1
- From labour onset to maximum cervical dilation
- Has latent phase and active phase, varying timing
- Multiparous women hit active phase earlier
Stage 2
- From maximum cervical dilation to fetal expulsion
Stage 3
- From fetal expulsion to placental expulsion
Stage 4
- The first hour after placental expulsion
- Uterine contraction happens here
List 10 drugs or agents that are teratogens.
What is the worst time to be exposed?
- Thalidomide
- Retinoic acid (Accutane)
- ACEi/ARBs
- Methotrexate
- Fluoroquinolones
- Ethanol
- Cocaine
- Phenytoin
- Lithium
- Cyclophosphamide
- SSRIs
- Warfarin
- Lots…
Worst Time (Organogenesis)
- Fetal day 21 – 56 (weeks 3 – 8)
List 6 factors associated with premature rupture of membranes?
- Extremes of age
- Smoker
- Low SES
- Prolonged standing jobs
- Placental abruption
- Prior gyne surgery
- UTI
- Bacterial vaginosis
- Multiple fetuses
List 5 questions that should be taken for all pregnant patients
- Estimated gestational age?
- Multiple gestation?
- Is there a history of vaginal bleeding?
- Were medications given or drugs taken?
- Is meconium present?
What are 5 contraindications to tocolytics?
- Fetal distress
- Lethal fetal anomaly
- Eclampsia/Pre-eclampsia
- DIC
- Sepsis
List 7 DDx for headache in pregnancy
- Tension
- Migraine
- Prolactinoma
- SAH
* 10% of maternal deaths! - CVST
- Pseudotumor cerebri (IIH)
- Intracerebral bleed
- Preeclampsia/Eclampsia
- Dissection
List 6 risk factors for placental abruption
Name one potential life-threatening complication
Risk Factors
- Trauma
- Preeclampsia
- Cocaine
- Maternal HTN
- Thrombophilia
- Prior abruption
- Prior miscarriage
- Parity
- Smoking
- Increased maternal age
Clinical Features
- Painful T3 vaginal bleeding
- Uterine tenderness/pain
- Fetal distress
- DIC
- Hypovolemia / Shock
Potential Life-threatening Complication
- Amniotic fluid embolus
What is the best test to assess for maternal-fetal mixing of blood?
Kleihauer-Betke Test
- Used to assess maternal-fetal mixing
- Detects as little as 5 mL of mixing
- Only 0.1 mL is needed for Rh sensitization
- Only used to determine if repeat doses are required
- 300 mcg RhoGAM will cover for:
- 15 mL of fetal RBC transfusions; or
- 30 mL of whole blood
What are the types of decelerations seen on fetal monitoring?
Decelerations refer to fetal heart rate.
They can occur around contractions or independently.
- Early: head being squeezed: safe
- Variable: cord compression
- Late: uteroplacental insufficiency
What are 6 factors affecting the vertical transmission of HIV?
- Maternal viral load
- Vaginal infections
- IVDU
- Low birth weight (likely born pre-mature?)
- Premature delivery
- PROM
- C-section vs Vaginal delivery
A woman is in an MVC and is pregnant, assuming she is totally stable, with no abdominal pain, no bleeding. How long should she be monitored?
4 hours of fetal monitoring if >24 weeks
Why would cholecystitis be difficult to diagnose in pregnancy?
- Big DDx for RUQ pain
* AFLP, Fitz-Hugh-Curtis, HELLP, etc. - WBC elevated (physiologic)
- ALP + Amylase elevated (physiologic)
- Gallbladder may be difficult to visualize on U/S
How do you deliver a breech baby?
- Call for help
- Done PPE, warmer, nursing, extra physician
- Hands off until umbilicus out
- Rotate child so the occiput is anterior
- Sweep each leg out of the way
- Rotate kid sideways and deliver each arm,
- Anterior arm first
- When it’s just the head: Mauriceau’s maneuver
- Essentially the baby becomes a bowling ball
- Flex their head and deliver that kid
List 8 risk factors for ectopic pregnancy
- Extremes of age
- PID history
- Previous ectopic
- Uterine Abnormalities
- IVF
- Smoking
- IUD
- Previous medical abortion
- Prior spontaneous abortion
Describe the pathophysiology, symptoms, diagnostic workup, treatment & complications of acute fatty liver of pregnancy (AFLP)
Pathophysiology
- Typically late in 3rd trimester
- Deficiency in the fetus’ fatty acid metabolism
- Accumulation of hepatotoxic metabolites in the maternal circulation
Risk Factors
- Primiparous women
- Twin pregnancy
Symptoms
- Flu-like symptoms, N/V, +/- RUQ pain
Workup
- CBC, lytes, urea, Cr, LFTs (elevated), coags
- Uric acid (elevated)
Treatment
- IVF resuscitation as needed
- Add dextrose (patients often hypoglycemic)
- Ob consult
- Delivery!
Complications
- Coagulopathy
- Jaundice
- Seizures
- DIC
- Hepatic encephalopathy
What is the definition of PPH? List 5 possible treatments for PPH.
Post-Partum Hemorrhage
- >500 cc blood loss in a vaginal delivery
- >1000 cc blood loss in C-section
Causes
- Tone
- Tissue
- Trauma
- Thrombotic Issues
Treatment
- Uterine massage, Remove clots
- Oxytocin 20 units IM/IV
- PGE2 1000 mcg PR
- Ergot 0.2 mg IM
- Hemabate 0.25 IM
- Laceration Repair
- OR
List 6 risk factors for pregnancy-induced HTN
- Obesity
- Advanced maternal age
- Smoker
- Sympathomimetics
- Previous pre-eclampsia
- CKD
- Black
What are the components of the biophysical profile?
- Fetal HR
- Amniotic fluid index
- Fetal muscle tone
- Body movements
- Breathing movements
Name 5 safe and 4 unsafe ABx in pregnant/breastfeeding moms
Safe Antibiotics
- Cephalexin
- Amoxicillin
- Amox-Clav
- Nitrofurantoin
- Azithromycin
- Clindamycin
Not Safe Antibiotics
- Ciprofloxacin
- Aminoglycosides
- TMP-SMX
- Fluconazole
- Tetracyclines
What test (other than ultrasound) can be done to help diagnose vasa previa?
Apt Test
- Alkali denaturation test
- Used to differentiate fetal blood from maternal blood
- Ideal for T3 pregnancy with vaginal bleeding
Results
- If blood turns pink = previa
- If blood turn yellow/brown = maternal
So there’s a 1/25 (4%) chance of any breech delivery. What are the types of breech and their prevalence?
- Frank-butt first: knees extended (60%)
- Complete: butt first: knees bent (5%)
- Incomplete/ Footling (35%)
List 6 causes of Rh sensitization. What is the timeframe to give RhoGam? Who should get it?
- Spontaneous miscarriage
- Uterine manipulation
- Threatened miscarriage
- Ectopic surgery
- Amniocentesis
- Abruption
- Trauma
Who should get it?
- Rh-negative women within 72h of blood exposure
Define term, preterm and post-term infants
Preterm
- < 37 weeks GA
Term
- 37 – 42 weeks GA
Post-Term
- > 42 weeks GA
Outline your management of a placental abruption
- MOVID, ABCs, consult Ob STAT
- Code Bleed for possible MTP
- Mother: IVF/blood/FFP/platelets PRN
- Fetus: NST, BPP, U/S
- Do U/S before pelvic (r/o previa)
- Apt test
- Mix blood with NaOH on slide
- Pink = Vasa previa
- Yellow/brown = Maternal blood
- RhoGAM 300 mcg IM
- If not already given at 28 weeks to Rh -ve mother
- Ob management
- C-section for fetal distress, continued bleeding etc.
What are 3 drugs used in pregnancy to treat HTN? What 2 drugs should you avoid?
Hypertension Drugs in Pregnancy
- Labetalol
- Methyldopa
- Hydralazine
Avoid: ACEi/ARBs
What 3 findings on U/S are suggestive of ectopic pregnancy?
- Lack of IUP
- Abdominal FF
- Adnexal Mass
What are the indications and reasons for giving tocolytics?
Delay labor for 48-72h to allow administration of steroids for fetal lung maturity if < 32 weeks GA
- Give betamethasone 12 mg IM q24h x2
You’re in a small peripheral hospital and a pregnant patient states she is having contractions: During a sterile cervical exam, what are 5 things you have to determine?
- Effacement (thinning of cervix)
- Dilatation (width of cervical opening)
- Position (relation of the presenting part to the birth canal)
- Station (relation of the presenting part to the ischial spine)
- Presentation (anatomic part leading in the birth canal)
What happens to the appendix during pregnancy?
Appendix rises toward RUQ as the pregnancy progresses
- U/S is still test of choice
- Most common DDx = pyelonephritis
- Consider this if bacteriuria
Reasons why appendicitis is hard to diagnose in pregnancy
- Increased WBC (physiologic)
- Appendix in RUQ
- May be hard to visualize with U/S
Define premature rupture of membranes (PROM). List 4 methods of detecting PROM
Membrane rupture prior to labour (regular contractions)
Methods of detecting PROM
- Light it on fire
* If brown = vaginal secretions
* If white/crystalized = amniotic fluid - Look under a scope
* Ferning = amniotic - Pelvic exam
* Pooled fluid or when they cough fluid gushes out - Nitrazine
* pH >6.5 will turn the paper blue
What is the incidence of:
- Breech presentation
- Shoulder dystocia
- Face presentation
- Brow presentation
- Breech: 1/25 (4%)
- Shoulder Dystocia: 1/300 (0.33%)
- Face: 1/500 (0.2%)
- Brow: 1/400 (0.25%)
Outline your approach for a suspected ectopic pregnancy
- Vitals
- Monitors, IV access
- Type and Cross, CBC, lytes, consent for blood
- RHoGam if Rh-
- US (POCUS or Formal)
- Obstetric consultation
List 4 possible indications for T3 ultrasound
- Count # of fetuses
- Establish presentation
- Locate placenta
- Diagnose cord prolapse
- Check reason for 3rd-trimester bleed
- R/O placental abruption
