OB Flashcards
Discriminatory zone
b-hCG 1500-2000 - 5 weeks
when gestational sac should be visible on TVUS
Naegele’s rule
1st day of LMP + 7 days - 3 mo + 1 yr
Gs and Ps
G - number pregnancies P - number of births -F - term births -P - preterm births less than 37 wks -A - abortions before 20 weeks -L - living children
Physiologic changes in pregnancy
BMR increases 10-20% - need 100-300 more calories/day
Plasma volume increases 30-50%, RBC mass increases 20-30%
- > physiologic anemia
- > systolic murmur, S3
Cardiac output increases 30-50%
BP decreases in early pregnancy -> nadir at 24-26 wks, return to normal by term
Relaxation of the lower esophageal sphincter -> GERD
Increase GFR -> decreased BUN and Cr
Increased procoagulation factors -> hypercoaguable state through first few weeks postpartum
Age of viability
24 weeks
Wt gain in pregnancy - Underweight - BMI less than 18.5 Normal Overweight (BMI 25-29.9) Obese (BMI >30)
Under - 28-40
Normal - 25-35
Overwt - 15-25
Obese - 11-20
Chorionic villus samping
10-13 weeks
Quad screen, amniocentesis
15-20 weeks
Screen for gestational diabetes
24-28 weeks
Administer anti-D immune globulin in Rh(D) negative
28 weeks
Or anytime risk fetomaternal hemorrhage
Screen for group B strep
35-37 weeks
Check for lung maturity
Lecithin-Splingomyelin ratio >2:1
Fetal alcohol syndrome
Dysmorphic facial features: short palpebral fissures, smooth philtrum, thin vermillion border
growth retardation
CNS abnormalities: microcephaly, intellectual deficits, behavioral problems, Learning disabilities (MC cause), impaired executive functioning
Hyperemesis gravidarum
N/V severe enough to cause wt loss of more than 5% of prepregnancy wt, dehydration, ketosis, and/or abnormal labs
Vitals: Weight, HR, orthostatic blood pressure
-tachycardia and hypotensive with dehydration
Labs:
hypokalemic, hypochloremic, metabolic alkalosis
Ketonuria
U/S: r/o gestational trophoblastic disease and multiple gestation -> higher level of hormones
Tx: IVF Electrolyte and thiamine repletion Antiemetics NG tube feeds, parenteral nutrition
Infant complications in pre-gestational diabetes
Spontaneous abortion/stillbirth Macrosomia Neonatal hypoglycemia Congenital malformations -cardiac defects -caudal regression syndrome - sacral agenesis
Maternal complications in pre-gestational diabetes
Preeclampsia
Polyhydramnios
DKA
Worsening of retinopathy, nephropathy
Management of pre-gestational diabetes
HgbA1c, urine protein:Cr, ECG, dilated eye exam
Insulin
DM diet - monitor glucose
2nd trimester: US and fetal echo
3rd trimester: fetal surveillance, US: look for macrosomia
Consider C/S if EFW more than 4500g
Induction at 39-40 weeks
Infant complications in gestational diabetes
still birth
macrosomia
neonatal hypoglycemia
Maternal complications in gestational diabetes
preeclampsia
polyhydramnios
Management of A1 diabetes in pregnancy
diet/exercise 3rd trimester US consider C/S if EFW more than 4500 g Induction at 40-41 weeks Post partum OGTT - 2 hour, 75 g
Management of A2 diabetes in pregnancy
Insulin 3rd trimester fetal surveillance, US Consider C/S if EFW more than 4500 g Induction at 39 weeks Post partum OGTT
Asx bacteriuria in pregnancy
screen of Ucx at first visit
treat positive Ucx -PO: nitrofurantoin (MC) amoxicillin Cephalexin Fosfomycin
Repeat Ucx 1 week after completion
Cystitis in pregnancy
S/S:
Dysuria, frequency, urgency
Suprapubic pain
Hematuria
UA: bacteriuria, pyuria, leukocyte esterase, nitrate
+ UCx
-PO: nitrofurantoin (MC) amoxicillin Cephalexin Fosfomycin
Repeat Ucx 1 week after completion
Pyelonephritis in pregnancy
Risk: progesterone -> smooth muscle relaxation -> dilation of ureters
S/S: Dysuria, frequency, urgency Suprapubic pain Hematuria Fever/chills N/V Flank pain CVA tenderness Pulmonary edema -> SOB
UA: bacteriuria, pyruia, leukocyte esterase, nitrite, WBC casts
Positive UCx
Tx: Admit IV Abx: ampicillin + gentamicin Ceftriaxone Meropenem Pip-tazo
Suppresive therapy remainder of pregnancy
Complications: Preterm birth Sepsis -> septic shock ARDS Maternal death
HELLP syndrome
Hemolysis, elevated liver enzymes, low platelets
pre-eclampsia + RUQ pain + bleeding
Amniotic fluid embolism
Amniotic fluid enters maternal circulation -> CV collapse, possible death
Features: Hypotension - cardiogenic shock Respiratory failure Unresponsiveness Excessive/prolonged bleeding (DIC) (looks like PE with DIC)
Occurs during Labor and delivery or a immediately postpartum
Dx of exclusion
Tx: ACLS protocols
Toxoplasmosis
Historical clues:
Infant findings:
Historical clues:
- exposure to cat feces
- ingestion of undercooked meat
Infant findings:
- chorioretinitis
- intracranial calcifications (diffuse)
- hydrocephalus (big head)
Tx: spiramycin
After 18 weeks: Pyrimethamine + sulfadiazine + folinic acid
pre-pregnancy infection offers immunity if reinfected during pregnancy
CMV
Historical clues:
Infant findings:
Historical clues: mono-like illness in mom
Infant findings:
- sensorineural hearing loss
- intracranial calcifications (periventricular)
- Microcephaly (small head)
MC congenital infection
No immunity from prior infection
Rubella
Historical clues:
Infant findings:
Historical clues:
Maternal infection - mild fever and rash - starts in and face and spreads to trunk/extremities
ppx - MMR virus - contraindicated 1 mo prior to conception and during pregnancy
Infant findings:
- sensorineural hearing loss
- cataracts
- patent ductus arteriosus
- pulmonary artery stenosis
- “blue berry muffin” rash
Parvovirus B19
Historical clues:
Infant findings:
Historical clues:
Maternal infection - fever and “slapped cheek” rash; arthritis
Infant findings:
- severe anemia
- cardiac failure
- hydrops fetalis
tx:
Serial U/S
Intrauterine blood transfusion
Prior infection offers immunity
Listeriosis
Historical clues:
Infant findings:
Historical clues: deli meats; mom infection - flu-like illness
Infant findings:
- granulomatous infantiseptica - rash, (widespread internal abscesses)
- stillbirth
Dx: blood culture
Tx: ampicillin + gentamicin
or TMP-SMX
Early manifestations of congenital syphilis
First two years of life
Hepatomegaly, elevated LFTs Disseminated maculopapular rash involving soles Blood tinged nasal secretions - snuffles Meningitis Skeletal abnormalities of long bones
Late manifestations of congenital syphilis
After first two years of life
Interstitial keratitis –> corneal scarring -> blindness
Sensorineural hearing loss
Facial abnormalities- frontal bossing, saddle nose
Hutchinson teeth - notching up teeth
Perforation of hard palate
Anterior bowing of tibia - saber shins
Varicella-zoster virus - maternal vs fetal vs neonatal infection
Maternal infection: chickenpox rash, pneumona
Fetal infection: scarring of kin in dermatomal pattern CNS abnormalities Chorioretinitis Limb hypoplasia
neonatal infection:
chickenpox rash, disseminated disease
-high mortality - 30%
Tx:
Maternal exposure - varicella IG
Maternal infection - acyclovir, +PNA -> hospitalize
Maternal infection around delivery -> acyclovir + VZV IG to infant
Neonatal infection -> acyclovir
HSV neonatal infection
vesicular skin rash Conjunctivitis meningoencephalitis Disseminated disease - sepsis, hepatitis, pneumonia Untreated mortality 80%
Group B strep
Vertical transmission -> sepsis, PNA, meningitis
Screen 35-37 weeks
Intrapartum ppx:
PCN G or ampicillin
allergy minor - cefazolin
risk of anaphylaxis - clindamycin insensitive, vancomycin if resistant
Ectopic pregnancy
Features: Amenorrhea vaginal bleeding Ipsilateral abdominal pain Referred pain to shoulder urge to defecate - d/t pooling of blood in Pouch of Douglas Dizziness, LOC Abdominal tenderness Adnexal mass Rebound tenderness, guarding - if ruptures
Stable - methotrexate, monitor bhCG to zero
Unstable - ABCs, immediate surgical management
Cervical insufficiency
Painless cervical dilation -> 2nd trimester loss
Dx: exam and U/S - cervical length less than 25 mm
Tx: cerclage
Associated with: Ehler’s danlos, previous trauma, LEEP
Intrauterine fetal demise (IUFD)
after 20 weeks
Causes: Fetal chromosome abnormality or congenital anomalies Abnormal placenta or umbilical cord Placental abruption Rh alloimmunization Congenital infections Maternal complications - HTN, DM idiopathic
Tx:
Expectant management
D&E
Induce labor - misoprostol, oxytocin
Risk DIC if wait
Intrauterine growth restriction (IUGR)
Fetal wt less than 10th percentile for GSA
Causes: Chromosomal/ congenital Multiple gestations TORCH infections Placental abnormalities low uteroplacental blood flow - HTN, DM, SLE Low pre-pregnancy BMI Poor wt gain during pregnancy smoking - esp 3rd trimester Cocaine use Teratogens
Symmetric - entire body small - early insult
Asymmetric - small abd, normal head - late insult
Dx: U/S
Tx: serial U/S
Fetal surveillance
early delivery
Macrosomia
EFW > 4500g
Risk: Advanced maternal age Hi prepregnancy BMI Excessive weight gain Post term Maternal diabetes
Dx: U/S
Complications: Shoulder dystocia, birth trauma Postpartum hemorrhage C/S Future increased risk of metabolic syndrome
Tx: C/S if EFW >5000 g (or >4500 g in DM pt)
Causes of oligohydramnios
less than 5 cm amniotic fluid index
Placental insufficiency
Obstructed urine flow - posterior urethral valves-males
B/L renal agensis -> Potter sequence
Tx: amnio infusion
Potter Sequence
“POTTER”
Pulmonary hypoplasia Oligohydramnios Twisted skin (wrinkled skin) Twisted face (facial deformities) Extremities (limb deformities) Renal agenesis
Causes of polyhydramnios
> 24 cm amniotic fluid index
esophageal/duodenal atresia Anencephaly Multiple gestation Uncontrolled maternal diabetes Congenital infections - parvovirus B19 Fetal anemia d/t RH alloimmunization
Tx: amnioreduction
Indomethacin (decrease renal a. flow)
-risk early PDA, limit to short term use, not in 3r trimester
Accelerations - fetal heart rate tracing
Increases of heart rate of more than 15 bpm for more than 15 seconds
Normal (reactive) nonstress test
At least 2 accelerations in 20 minutes - 15x15
if less than 32 weeks - 10x10
Biophysical profile
Nonstress test Amniotic fluid volume Fetal breathing Fetal movement Fetal tone - flexion and extension
score 2 if normal, 0 if abnormal
total of 8-10 reassuring
Early deceleration
mirrors contraction - nadir with nadir
head compression
Variable deceleration
V shaped
no relationship to contraction
umbilical cord compression
Late deceleration
U shaped
FHR nadir after contraction nadir
uteroplacental insufficiency
Fetal hypoxia
Sinusoidal pattern to FHR
severe fetal anemia
management of non-reassuring FHR tracing
administer maternal O2, turn to left lateral decubitus
DC oxytocin, consider correction of hyperstimulation (tocolytic)
IVF bolus
Sterile vaginal exam - check for cord prolapse
Consider immediate delivery - C/S
Twin to twin transfusion syndrome
complication of monochorionic twin pregnancies
Vascular anastomoses link the fetal circulations -> blood from one twin flows to the other twin
Donor twin - anemia, growth restriction, oligohydramnios
Recipient twin: polycythemia, volume overload, heart failure, polyhydramnios
Erythroblastosis fetalis
Rh(D) negative mom with IgG antibodies against Rh(D)
Ab cross placenta, attack fetal RBCs -> hemolytic disease of fetus
Hydatidiform mole (molar pregnancy)
S/S:
Amenorrhea, positive pregnancy test, S/S of pregnancy
Vaginal bleeding
Pelvic pain/pressure
Uterine size does not match gestational age
Hyperemesis gravidarum
hyperthyroidism - hCG activates TSH receptor
preeclampsia before 20 weeks
passage of tissue with grapelike appearance
Dx:
Quant hCG
US: snowstorm - abnormal or absent fetus
-Theca-lutein ovarian cysts
Tx: D&C
follow hCG to zero
Wait at least 6 months before trying to conceive- to detect recurrence
Choriocarcinoma
Malignant form after gestational trophoblastic disease
- half arise from complete moles
- SBAs, ectopic pregnancy, normal pregnancies
Mets: lung (MC), vagina, brain, liver
Presentation:
Recent pregnancy
Persistent brown, bloody discharge
Pulmonary sxs - SOB, cough, hemoptysis
Dx: pelvic exam Quant hCG - extremely high US: uterine mass with areas of necrosis and hemorrhage CXR
Tx: methotrexate
+/- surgery
Follow hCG levels to zero
Wait at least one year before attempting to conceive
Placenta previa
Risk factors: Increasing maternal age Multiparity Multiple gestations History of uterine surgery History of C-section
Presentation:
Painless vaginal bleeding late in pregnancy
Dx: US before pelvic exam - risk massive hemorrhage
Tx: Asx - pelvic rest, serial u/s, C/S 36-37 weeks Bleeding previa: -resuscitation - IVF, blood transfusion -FHR monitoring -glucocorticoids to promote lung maturity -inpatient bed rest if bleeding resolves -if continues or abnormal FHTs -> C/S
Vasa previa
Unprotected fetal vessels overlie cervical os
Ruptured membranes -> compression or laceration of fetal vessels -> fetal hypoxia or hemorrhage/exsanguination
Dx: US
Suspect if ROM followed by bleeding and nonreassuring FHT
Tx: C/S 34-35 wks
Placental abruption
risk factors: Prior abruption Hypertension Trauma Smoking Cocaine
Features:
Sudden onset, painful vaginal bleeding late pregnancy
contractions
Fetal distress - bradycardia, late/prolonged decels
DIC possible complication
Dx: US, clinical
tx: emergent C/S
Test to confirm ruptured membranes
Sterile speculum exam - pooling fluid in posterior vaginal vault
Nitrazine paper test - blue in amniotic fluid
Microscopy - ferning pattern
Amnisure
US: low amniotic fluid volume
Management of PROM less than 34 weeks
Admit
Betamethasone or dexamethasone for fetal lung maturity
Abx:
IV ampicillin 2g q6hr + gentamicin 250 mg q6 hr x 48 hours
PO amox 250 q8hr + azithromycin 233 mg q8 hr x5 days
Management of PROM greater than 34 weeks, or evidence of infection
induce labor - oxytocin
Complications of premature rupture of membranes
Chorioamninitis if greater than 18 hrs
cord prolapse
placental abruption
preterm labor
Preterm labor
less than 37 weeks
Contractions -> cervical changes
Less than 34 weeks: Admit Corticosteroids for lung development Consider tocolysis Mag sulfate for neuroprotection under 32 weeks \+/- PCN for GBS
over 34 weeks: allow labor
Risk: Placental abruption PROM Prior preterm birth Multiple gestations UTI/STI uterine abnormality cervical insufficiency
Chorioamnionitis
Infection of fetal membranes, placenta, and amniotic fluid
Risk factors: PROM longer than 18 hrs Prolonged labor Multiple cervical exams Meconium fluid Internal monitors
Dx: clinical
Features: Maternal fever Maternal/fetal tachycardia (fetal >160) Uterine tenderness Purulent amniotic fluid
Tx:
IV ampicillin + gentamycin
Delivery
Methods to induce labor
Cervical ripening - mechanical cervical dilators, misoprostol (PGE1),
-dinoprostone (PGE2) -> tachysystole - too strong contractions, fetal distress
IV oxytocin - stop if tachysystole
Amniotomy - risk cord prolapse
Membrane stripping
Nipple stimulation
Signs of placental separation
Sudden gush of blood
Lengthening of the umbilical cord
uterus rises to anterior abdominal wall
Uterus becomes firmer and more globular in shape
1st stage of labor
latent phase - onset of regular contractions to 6 cm
-nulliparous - less than 20 hours
-multiparous - less than 14 hrs
management of protraction/arrest: expectant mgmt, amniotomy +/- oxytocin
Active phase - 6 cm to 10 cm
management of protraction -> oxytocin; arrest -> C/S
2nd stage of labor
10 cm -> delivery
Nulliparous 3 hrs or less
Multiparous 2 hrs or less
+1 hr if epidural
Protraction/arrest:
expectant mgmt, oxytocin, operative vaginal delivery, rotation of fetal occiput, C/S
3rd stage of labor
delivery of infant to delivery of placenta
less than 30 min
-otherwise manual removal
adequate uterine contractions
200 montevideo units or more
add amplitude of each contraction in 10 minutes
labor arrest vs protraction
labor protraction - slower than normal
Labor arrest - not progressing at all
no cervical change in patient 6 cm + and ruptured membranes despite:
-at least four hours of adequate contractions or
-at least six hours of inadequate contractions + oxytocin
Cardinal movements of labor
Engagement Descent Flexion - chin to chest Internal rotation (towards midline) Extension - of head External rotation Expulsion
Uterine rupture
Risk:
Prior uterine surgery (C/S)
Labor induction/augmentation
Features: Fetal bradycardia (less than 110) Maternal abdominal pain - constant Loss of fetal station Change in shape of uterus Maternal tachycardia and hypotension
Tx:
emergent C/S with repair or hysterectomy
Management of shoulder dystocia
suprapubic pressure
McRoberts maneuver - hyperflex legs
Delivery of posterior arm/shoulder - Barnum’s maneuver
Rubin manuever - rock shoulders side to side
Wood maneuver - rotate posterior shoulder 180 degress may release it
Intentional fracture of clavicle
Zavanelli maneuver - last resort - push back in with STAT C/S
Indication for C/S
Arrested labor Abnormal fetal heart tracing Malpresentation - breech prior C/S Abnormal placentation - previa, accreta, increta, percreta Acute placental abruption uterine rupture multiple gestation suspected fetal macrosomia HIV load >1000, active HSV lesions prior vaginal delivery with 4th degree tear
Postpartum hemorrhage definition
500 ml vaginal
1000 ml c/s
Causes of postpartum hemorrhage
Uterine atony (MC) - open spiral arteries Retained placental tissue Placenta accreta/increta/percreta genital lacerations uterine rupture coagulopathy
Uterine atony
Risk: overdistended uterus chorioamnioitis induced/augmented labor prolonged labor
Presentation:
bleeding continues after placenta delivered
Big, soft, “boggy” uterus
Tx:
fundal or bimanual massage
Exam uterus for placental fragments or large blood clots
Uterotonic agent: oxytocin, methylergonovine (contra in HTN), carboprost (contra in asthma), misoprostol, dinoprostone
IVF, blood
Consider uterine artery ligation or hysterectomy
Intrauterine balloon to tamponade
Sheehan syndrome
massive postpartum hemorrhage -> hypotension -> underperfusion of pituitary gland -> pituitary necrosis -> hypopituitarism
S/S of deficiencies in:
FSH/LH - amenorrhea, breast atrophy, loss of pubic/axillary hair
ACTH - hypotn, hyponatremia
TSH - fatigue, cold intolerance, wt gain, constipation, dry skin
Prolactin - failure to lactate
GH - decrease in lean body mass
Postpartum endometritis
Risk factors: C/S Chorioamnionitis Prolonged labor/PROM multiple cervical exams internal monitoring manual removal of placenta
Features: fever tachycardia urterine tenderness Foul-smelling lochia
Dx: clinical
Tx: ampicillin + gentamicin +/- clindamycin (anaerobic coverage)
Contraindications to breastfeeding
HIV infections Drug or alcohol abuse Active TB active herpes on breast chemotherpay Infant with galactosemia
mastitis
S. aureus (MC)
Features: tender, erythematous, swollen area fever myalgias malaise
Dx: clinical
US r/o breast abscess
Tx: continue breastfeeding/pumping Abx: dicloxacillin - antystaph if MRSA suspected - clindamycin, TMP-SMX, vancomycin
If abscess - I&D
