Obstetrics Flashcards
Nagele Rule
Estimation of delivery date
LMP - 3 months + 7 days
At what gestational age do you consider resuscitation?
Pre-term Early Term Full Term Late Term Post-Term
No resuscitation if < 22 wks, case by for 23-25 wks, always resuscitate if 25+ wks
Pre-term 25 - 37 wks
Early Term 37 to 38 and 6 days
Full Term 39 to 40 and 6 days
Late Term 41 wks to 41 wks and 6 days
Post-Term 42 wks +
Goodell Sign
Ladin Sign
Chadwick Sign
Goodell - FIRST (approx 4 wks), softening of cervix
Ladin - softening of midline uterus
Chadwick - blue discoloration of cervix and vagina
When should a gestational sac appear on US?
4-6 wks
or beta-hCG of 1500 +
Physiologic Changes in Pregnancy
Inc HR, inc plasma volume, dec peripheral resistance
Dec residual volume, normal FEV1/FVC
Inc tidal volume but normal RR, inc minute ventilation –> respiratory alkalosis
Inc GFR
Hydronephrosis 2/2 ureter compression and progesterone decreasing ureter peristalsis
Inc neutrophils, sometimes dec platelets (tests if < 80,000)
Anemia (dilutional)
Testing by Trimester
1st - blood tests, pap smear, gonorrhea and chlamydia, may do US to confirm gestation age, FIRST screen (US, beta hcg and PAPP-A)
2nd - triple or quad screen w/ AFP, anatomy US at 20 wks
3rd - CBC (for anemia), 1 hr glucose test, repeat cervical cx for chlamydia and gonorrhea, group B strep swab
Timing of Chorionic Villous Sampling v. Amniocentesis
CVS - 10 to 13 wks with catheter
Amnio - 15 to 17 wks with needle
BOTH YIELD KARYOTYPE
Biophysical Profile
NST - 2 accelerations in 30 min
1 episode of fetal breathing > 30 sec in 30 min
3 movements in 30 min
1 flexion/extension episode in 30 min
Amniotic fluid index - no vertical pocket > 2 cm
**2 pts per category, BPP of 4 or less may mean fetal compromise
Acceleration
Early Deceleration
Late Deceleration
Variable Deceleration
Acceleration - inc by 15 BPM for 15-20 seconds
Early Decel - mirrors contractions, due to head compression
Late Decel - BAD, dec in HR after contraction has started, decreased placental perfusion –> fetal hypoxia
Variable Decel - no relationship to contractions, due to umbilical cord compression which inc peripheral resistance
Stages of Labor
Stage 1 - onset to full cervical dilation
- Latent - up to 6 cm (6 hrs prime, 4 hrs)
- Active 6 to 10 cm (1.2 cm/hr prime or 1.5 cm/hr)
Stage 2 - delivery of baby (up to 3 hrs prime, 30 min in multipara)
Stage 3 - delivery of placenta (30 min)
Signs of Placental Separation
umbilical cord lengthening
uterine fundus lowering/anterior
uterus becomes firm
Mgt of Ectopic Pregnancy
Dx - beta HCG and US
If unstable … surgery (try for salpingotomy - just hole)
If stable … CBC, type and screen, LFTs
Methotrexate - check for 15% dec in beta HCG at 4-7 wks, if less than 15% do second dose, if 2 doses still inadequate –> surgery (cont to check weekly until beta hCG is 0)
Contraindications to Methotrexate for Ectopic
Immunodeficiency
Non-compliant
Liver disease
Ectopic > 3.5 cm
If fetus has heartbeat
Co-existing viable pregnancy
Breastfeeding
Abortion Types (6) + Tx of Each
Complete - no products, os closed, outpatient follow-up
Incomplete - retained products, os open, D&C or miso
Inevitable - products intact, bleeding, dilated, D&C or miso
Threatened - products intact, bleeding, NOT dilated, BED REST
Missed - all products but not viable, os closed, D&C or miso
Septic - infection of uterus, D&C and IV abx (cefoxitin and doxy or gentamicin and clinda)
When should you deliver in pre-term labor? (6)
severe HTN (160/110)
maternal cardiac disease
cervical dilation > 4 cm
maternal hemorrhage (DIC, placental abruption)
fetal death
chorioamnionitis (even if fetus will not survive)
How do you delay pre-term labor?
Betamethasone - inc surfactant, lung maturity (peaks at 48 hrs)
Tocolytics - CA CHANNEL BLOCKERS, dec uterine contractions (alternative - terbutaline)
**add ampicillin and 1 dose azithromycin if premature rupture of membranes (to prevent chorio)
Tx of Intrauterine Infection
Amp + gentamicin
Add clindamycin if C section
Placenta Previa v. Placental Abruption (presentation, risk factors, tx)
Both present with bleeding, do abdominal US first (abruption may not be seen but rules out previa)
Previa - painLESS bleeding, risk factors include prior uterine surgeries/ C sections
- Tx is pelvic rest and no sex
- Plan for C section at 36-37 wks if persists
- Immediate C section if hemorrhage, 4 cm dil, fetal distress
Abruption - painFUL bleeding and contractions, can be severe (hypovolemia, DIC), risk factors include HTN, cocaine, tobacco, trauma
- C section if uncontrolled, expanding hemorrhage, fetal distress, rapid placental separation … otherwise vaginal okay
Indications for C section based on gestational wt
> 4500 g in diabetic mothers
> 5000 g in non-diabetic mothers
When should Rho-gam be given?
Anytime unsensitized RH neg mom (no titers yet) has exposure to fetal blood cells that may cross placenta
- abortion
- amniocentesis
- vaginal bleeding
- placental abruption
- delivery
Also given to unsensitized mom’s at 28 wks –> again at delivery
**Check Rh status at first pre-natal visit, if Rh neg get titers
Definition, RF and Tx of Hyperemesis Gravidarum
6 lb wt loss or 5% body weight loss
Tx = diet modification to avoid triggers, acupuncture, ginger, vit B6
Antihistamines (benadryl) if severe
Metoclopramide if persists
ondansetron (last resort)
RF = twins, hydatiform mole, previous hx
Wt Gain Recs in Pregnancy
If BMI < 18 … 28-40 lb
If BMI 18-24.9 (normal) … 25-35 lb
If BMI 25 - 29.9 … 15-25 lb
If BMI > 30 … 11-20 lb
Screening and Mgt if Asymptomatic Bacteriuria
Screen at 12-16 wks w/ UA and culture
TREAT - nitro, amoxicillin, cephalexin
Pyelonephritis Tx in Pregnancy
IV ceftriaxone (aztreonam if allergy) inpatient
Evaluate urine cultures monthly for recurrent bacteriuria
Tx of PE/DVT in Pregnancy
LMWH
Stop 24 hrs before delivery
Resume 12 hrs after C sect and 6 hrs after vaginal
Cont 6 wks post-partum
How do you differentiate acute fatty liver of pregnancy from pre-E?
AFLP - signs of hepatic insufficiency (hypoglycemia, encephalopathy) and coagulation abnormalities
-IMMEDIATE DELIVERY
Pre-E - just elevated LFTs
Chronic HTN
Gestational HTN
Pre-E
Pre-E w/ severe features
HELLP
Eclampsia
Chronic HTN - prior to 20 wks, no protein in urine (labetolol, nifedipine, hydralazine)
Gestation - after 20 wks, no protein in urine (“severe gestational HTN” if > 160/110 but still no protein in urine)
Pre - E BP 140-160/90-110 and protein in urine (induce if at term, if not steroids and Mg)
Severe Features - BP > 160/110, mental status changes, vision changes, RUQ pain (swelling of Glisson capsule)
- Tx = steroids, Mg sulfate, hydralazine
HELLP - hemolysis, elevated LFTs, low platelets
- same treatment
Eclampsia - pre -E + seizure
- same treatment
What additional tests do you do in pregnant woman w/ pre-gestational DM?
EKG
Baseline 24 hr urine - for protein and creatinine clearance
HgbA1c
Baseline retina exam (retinal exam every trimester)
Eval for Gestational DM and Tx
24-28 wks
1 - 1 hr glucose load (50g) if > 130-140 positive do next test
2 - fasting glucose tolerance test - meas fasting glucose - 100 g load - measure at 1 hr, 2 hr and 3 hr POS if 2/4
Tx = diet and exercise first, insulin is gold std (can also use metformin and glyburide)
In thyroid disease, what can and cannot cross placenta?
Can cross - TRH, TSH receptor antibodies
CANNOT cross - TSH, T4
How does beta-hcg affect thyroid disease?
Stimulates TSH receptor because share same alpha unit - inc thyroid hormone (why hydatiform mole often presents with hyperthyroid sx)
Tx of Hyperthyroid in Pregnancy
PTU 1st trimester
Methimazole 2-3rd (can cause cutis aplasia)
Definition and Mgt of Prolonged Latent Stage
> 20 hrs in prime
14 hrs multiparous
Rest and hydration
Definition, Causes, Tx of Protracted Cervical Dilation
Vs. Active Phase Arrest
SLOW DILATION
< 1.2 cm/ hr in prime
< 1.5 cm /hr in multiparous
Causes = 3 P’s (passenger, power, pelvis)
- if contractions too weak or too far apart –> oxytocin
- if cephalopelvic disproportion –> C section
Arrest = no change in 4 hrs if adequate contractions (200+ montevideo units) OR no change in 6 hrs if inadequate contractions
Presentation and Mgt of Uterine Inversion
Smooth round mass protruding
Esp if fast delivery, placenta accreta, uterine abnormalities, macrosomia, short cord
Tx = STOP uterotonics (relax for repositioning), manual repositioning, may need nitroglycerin/terbutaline/mg to further relax
Laparotomy as last resort
Definition of Postpartum Hemorrhage, 4 Main Causes, Mgt
> 1000 mL blood loss
early if < 24 hrs
1 - TONE (atony) #1 reason
2 - Tissue (retained placenta)
3 - Trauma (laceration)
4 - Thrombin (coagulopathy)
Mgt - bimanual exam (r/o rupture or retained placenta), uterine massage, may need oxytocin (constriction)
Tx of Vasa Previa, Umbilical Cord Prolapse & Uterine Rupture
Vasa Previa - torn umbilical vessels over os –> emergency C section
Umbilical cord prolapse - sudden fetal bradycardia or variable decelerations with palpable cord on vaginal exam –> elevate fetus to avoid cord compression and emergency C section
Uterine rupture - sudden loss of fetal station and bump in abdomen –> laparotomy because fetus in abdomen
If woman has prior uterine rupture what do you do in future pregnancies?
Planned C section at 36 wks
How do you distinguish between 3 types of twins and specific complications of each?
Monochorionic, monoamniotic - no thin membrane between, risk of cord entanglement and conjoined twins
Monochorionic, diamniotic - T sign, risk twin-twin transfusion syndrome
Di, di - lambda sign
HSV Mgt in Pregnancy
If prior HSV - acyclovir from 36 wks to delivery
If active disease in GU lesions or prodrome - C section
If no active disease - vaginal delivery okay
