OB Flashcards
where is AFP produced
fetal yolk sac and liver
what is elevated AFP
> 2.5 MoM (multiples of median)
What causes increase in AFP?
What about decrease
Increase: open NTD, abd wall defect, multiples, fetal maternal hemorrhage, germ cell tumor, fetal demise, placental conditions, underestimation of GA
Decrease with T21
what should you do if you have elevated MSAFP
evaluate with US, correct GA consider amnio
Dont need increased antenatal surveillance based on isolated elevated AFP
Criteria for breech vaginal delivery
counseled on risk of cord prolapse or head entrapment
37weeks plus
No prior CD
2500-4000g
frank or complete breech
normal AFI
adequate pelvis
no fetal anomalies
non hyperextended neck
spontaneous/normal labor course
experienced provider
% of preg breech
% of CS for breech
3-4 % of pregnancies are breech
17% of CS due to breech
risk of fetal death with FGR <10% and <5%ile
<10: 1.5%
<5: 2.5%
risk of recurrence for prior preg with FGR
20%
when to offer genetic counseling +/- amnio for FGR
-diagnosed before 32w
-FGR + poly
-fetal malformation
Major markers for T21
duodenal atresia
Cardiac (ASD, TOF, AV canal defects)
Soft markers
Which have the highest liklihood ratios
Which one is the best predictor
echogenic cardiac focus
pyelectasis
short femur length
choroid plexus cyst
echogenic bowel, thickened NT, and ventriculomegaly even when isolated are higher likelihood ratio
isolated finding of thickened nuchal skin highest risk of aneuploidy
what is the importance of NT and nasal bone
NT detection rate for T21 being 64-70%
cystic hygroma associated with T21 in about 50% of cases
Hypoplastic or absent nasal bone can be detected in 62-70% of fetuses with down syndrome, only 1% of normal fetuses
1/3 of cases with thickened NT will have chromosomal defects, T21 accounts for 50% of those
omphalacele
1:5000
midline defect in abdominal contents herniate
covered by amnion and peritoneum
has liver herniation
can look like normal embryo at 9-11 weeks
50% associated with cardiac defects
defects larger than 5 cm delivered by CS
umbilical cord insertion at apex of defect
gastroschisis
1:2500
full thickness defect, R paraumbilical
no liver herniation
no overlying membrane
never looks like normal embryo
no increase in chromosomal abnormalities
can deliver vaginally, immediate repair. can be done if you can return abd contents, in about 80% of cases
when to change EDD based on GA and CRL discrepancy from LMP
if < 9w, change if more than 5d
from 9-15w6d, change if more than 7d
from 16w-21w6d, change if more than 10d
from 22w to 27w6d change if more than 14d
from 28w and up, change if more than 21d
risk factors for NTDs
-environmental factors
-medications (anti epileptics carbamazepine, valproic acid)
-maternal hyperthermia
-obesity
-hispanic population
-genetics. chances if 1 prior sibling is 3.2%, two prior is 10%
what women are at high risk of NTD and what dose should they take
4 mg (4000 mcg) 3 mo before pregnancy and continue until 12w
women with previous preg affected by NTD
women who are affected by NTD themselves
those who have a partner affected
those who have a partner with a previous affected child
folate resistant NTDs
poor glucose control in first trimester
hyperthermia
obesity
aneuploidy
genetic disorders
those on anti epileptic meds
Delivery timing for FGR
EFW 3-10%, no concurrent findings
38-39 w0d per smfm (39w6d per acog)
delivery timing for EFW <3%ile, no concurrent findings
37w or at time of diagnosis if later
Elevated UAD delivery timing
37 weeks
Absent end diastolic flow delivery timing
33-34w
reversed end diastolic flow delivery timing
30-32w
delivery timing with FGR and concurrent conditions (oligo, preeclampsia, cHTN)
34-37w6d
What are the causes of FGR
Maternal- cHTN, pregestational DM, Renault insufficiency, AI dz, PIH, substance abuse, teratogens
Placental- abruption, SUA, velamentous or marginal cord, TTS
Fetal- multiples, chromosome abnormalities, structural anomalies (cardiac, anencephaly), infections
delivery timing for uncomplicated di/di twins
38-38w6d
delivery timing for di/di twins, complicated
individualized
delivery timing for mo/di uncomplicated
34-37w6d
delivery timing for mo/di complicated
32-34w0d by CD
Clinical presentation of toxo ?
Diagnosis?
intracranial calcification
chorioretinitis
hepatosplenomegaly
hearing loss
low IQ/neurodevelopmental issues
(All head problems)
Igm- only that pos is acute infection
If iGG pos and igm neg- immunity from previous infection
CMV clinical presentation
chorioretinitis
hepatosplenomegaly
abdominal and liver calcifications
FGR
fetal hydrops
echogenic bowel
ventriculomegaly
Parvovirus
what is the pathophysiology
Vertical transmission rate
Presentation
Diagnosis
Treatment
fetal survival rate
virus replicated in bone marrow, causes anemia, heart failure and hydrops
50% of population is immune (IgG positive)
vertical transmission is 25%
infection in first ti > spontaneous abortion
in late 2nd and 3rd tri > hydrops and IUFD
Mom: rash, arthritis, flu like illness, most asx
diagnosis: ELISA for IgG and IgM. PCR of amniotic fluid is more sensitive.
Igg pos- immune
If both igg and igm both positive or both neg- monitor for signs of infection. Repeat testing in 4 weeks.
Tx: PUBS looking for anemia and psb transfusion if hydrops
serial weekly US for fetal well being, rule out hydrops for 2 months after exposure. MCA doppler studies to assess degree of anemia
Fetal survival w/ treatment: 80%, w/o treatment 20-50%
treatment for toxo
spiramycin to decrease placental transfer
treat affected infant with pyrimethamine, sulfadiazine, folinic acid for one year
varicella pneumonia
20% of pregnant women with varicella, mortality 5-15%
treat with IV acyclovir and ICU admission
postexposure ppx for varicella non immune pregnant patients
VZIG within 10 days, ideally within 96h OR acyclovir (800 mg PO 5x daily for 7d)
Diagnosis of cmv
transmission rate for primary CMV
Recurrent CMV?
Igm is not reliable
Get igG and avidity testing
High avidity- infection more than 6 months ago. Low avidity- infection less than 2-4 months ago.
If you have a pos IgM- can be new or chronic cmv
Primary: 30%. 30% of infected fetuses, neonatal dz will occur. Of all infected neonates, 305% will die
Secondary: <2%, negligible
when is the highest risk for neonatal effects with maternal varicella infection
if maternal infection is <5 days before delivery (no time for passive immunity) or 2 days after
high rate of neonatal infection if preg woman infected and delivery before or after onset of rash
Give VZIG to neonate delivered by mom with varicella 5 days before to 2 days after delivery.
IV acyclovir to baby if signs of neonatal infection
quad screen results for second trimester screen
T21
T18
T21: high HCG, estriol low, inhibin up, MSAFP down
T18: HCG down, estriol down, inhibin NA, MSAFP down
what is first trimester screening
NT
HCG
PAPP-A
integrated screening
PAPP-A with NT AND second trimester screen
-results collected but not reported until all tests done. sensitivity 95%
-without NT, serum integrated screen, sensitivity 85-88%
what is sequential screening
first trimester screen pos: offer diagnostic testing
first tri screen neg: second tri screening offered
sensitivity 95%
Final risk assessment incorporates both tests
CVS vs amnio
amnio: can screen for AFP and diagnosis NTD, CVS cannot
amnio tests individual cells, CVS does tissue
amnio: after 15w, CVS at 10-12w
karyotype vs FISH vs Chromosome microarray
karyotype: chromosome abnormalities, culture cells
FISH: CH 13, 18, 21, X, Y. Confirmatory cultures cells
Miroarray: copy number variants (duplicated or deleted sections of DNA). living cells not required, preferred test for stillbirth
situations that require VTE ppx in preg and pp
-hx of unprovoked VTE
-low risk thromophilia with single previous episode of VTE
-high risk thromophilia w/o prior VTE (FVL homozygous, prothrombin homozygous, heterzygous for FVL and prothrombin, antithrombin deficiency)
-high risk thrombophilia with prior VTE
-two or more episodes of VTE (get intermediate or therapeutic dosing)
-two or more episodes of VTE (receiving long term anticoag, get adjusted dose )
is testing reliable during preg?
is testing reliable during thrombosis?
is testing reliable with anticoag
1) FVL
1) pregnant- yes
2)thrombosis- yes
3) anticoag- no
is testing reliable during preg?
is testing reliable during thrombosis?
is testing reliable with anticoag
- prothrombin gene mutation
1) pregnant- yes
2) thrombosis- yes
3) anticoag- yes
is testing reliable during preg?
is testing reliable during thrombosis?
is testing reliable with anticoag
-protein C defeciency
<65%
1) pregnant- yes
2) thrombosis- no
3) anticoag- no
is testing reliable during preg?
is testing reliable during thrombosis?
is testing reliable with anticoag
-protein S deficiency
<55%
1) pregnant- no
2) thrombosis- no
3) anticoag- no
is testing reliable during preg?
is testing reliable during thrombosis?
is testing reliable with anticoag
-antithrombin
1) pregnant- yes
2) thrombosis- no
3) anticoag- no
how do you diagnose APLS
lupus anticoagulant, anticardiolipin, and anti b2 glycoprotein antibodies (IgG and IgM) on 2 or more occasions 12w apart
PLUS
vascular thrombosis (arterial or venous, or small vessel in any tissue or organ)
OR
one or more unexplained deaths of normal fetus at or beyond 10w
OR
one or more premature births of normal neonate before 34w because of eclampsia or preeclampsia, or features c/w placental insufficiency
OR
three or more unexplained consecutive losses before 10w
what is the half life of rhogam?
23 days. Dont need to give another dose if have delivery (or other event like ECV, car accident etc) within 3 weeks
what vaccines do you need if you have had splenectomy
pneumococcus, haemophilus influenzae, meningococcus
risk of T21 and any major anomaly for age range
35
40
45
50
35: t21: q:350, any 1:200
40: t21: 1:100, any 1:50
45: t21: 1:30, any 1:20
50: t21: 1:10, any 1:5
carrier screen: what conditions should you offer screening to everyone for?
SMA, CF, and screen for anemia
what should you offer AJ screen for?
tay sachs, CF, canavan, familial dysautonomia
Fragile X inheritance
XL recessive- FMR1 gene. CGG repeats
MC inherited cause for intellectual disability
unaffected: <45 repeats
intermediate: 45-54 repeats - no clinical sig
premutation: 55-200 repeats - tremor, ataxia, POI
full mutation: >200 repeats
when to screen for fragile X
known carrier
ID of unknown etiology or family hx of ID
unexplained ovarian sufficiency/failure (high FSH before 40)
autism
muscles cut during episiotomy
superficial transverse perineal
bulbocavernosous muscle
deep transverse perineal
+/- external anal sphincter
outlet forceps
scalp visible at introitus without separating labia
fetal skull at pelvi floor
head is at or on perineum
head in OA or OP
rotation not >45 degrees
low forceps
vertex higher than outlet, but below +2 station
rotation <45 degrees
low foceps with rotation: >45 degrees
mid forceps
station above +2
emergency CS under local
extreme emergency only
lidocaine 7 mg/kg 0.5% with epinephrine, max dose 60 cc
patient counseling and consent
midline vertical
infiltrate skin and parietal/visceral peritoneum
side effects of lidocaine
metallic tase in mouth
peri oral numbness
tinnitus
slurred speech and blurred vision
altered consciousness
convulsions
cardiac arrhythmias
cardia arrest
perimortem CS
best outcomes if delivered at <5 min
within 15 minutes have 67% fetal survival
perform if maternal CPR unsuccessful and uterus to umbilicus or above
heart NYHA classification
1: no limitation to activity
2- mild sx with regular activity
3-marked sx with regular activity
4- sx at rest
treatment for endocarditis ppx
amp 2g PO or amoxicillin 2g IV prior to procedure
things to keep in mind with mitral stenosis pt in labor
avoid fluid overload
epidural
vaginal delivery preferred (avoid valsalva, pt labor down, shorten second stage)
supplemental oxygen
positioning (reverse T, avoid legs above heart)
3rd stage is most risky due to fluid shifts
people with what heart conditions shouldn’t become pregnant
class IV heart disease
pulmonary HTN
severe cardiomyopathy
severe aortic steonsis (<1 cm) or bicuspid aortic valve diameter >50 mm
marfan syndrome with dilated aortic root (>45 mm)
Ejection fraction <30%
hepatitis B Antibody profile for
immune prior infection
immune vaccinated
acute infection
chronic infection
immune prior infection: HBcAb positive, if acute, IgM+, if chronic IgG+
immune vaccinated: HBsAb positive
Acute HepB: HBsAg psoitive, HBcAb IgM positive
Chronic HepB infection: HBsAg positive, HBcAb IgG positive
if HBsAg is positive, get viral load. If >200k, may need antiviral treatment
treatment for HIV
in preg and during labor and delivery
prenatal: HAART. 3 drugs, includes zidovudine
in labor: prior CD: zidovudine IV, load with 2mg/kg over 1 hour, start 3h before surgery. Maintenance 1 mg/kg/hr until delivery
Dont need to give it for laboring patient with viral load <1k
Route of delivery is CD if viral load >1k copies at 38w or if viral load is unknown and SROM has not yet occured
when to start workup for recurrent pregnancy loss
definition is 3 or more losses, but start workup at 2nd loss
what are some causes of recurrent pregnancy loss and workup
UGLIIM
U: uterine: saline sono/HSG
G: genetic: karyotype of parents and abortus
L: lifestyle/environmental: urine toxicology
I: immunologic: APLS testing
I: infection
Metabolic: TSH/TPO ab, glucose
mechanism of action of terbutaline
selective b2-receptor agonist that produces relaxation of smooth muscle found principally in bronchial, vascular and uterine tissues.
indications for cerclage
history indicated:
-one or more second trimester pregnancy losses related to painless cervical dilation in the absence of labor or abruption
-prior cerclage due to painless cervical dilation in the second trimester
Physical exam:
-painless cervical dilation in the second trimester
US
-currently pregnant, prior spontaneous preterm birth less than 34 weeks and short cervix (<25 mm) before 24 weeks gestation
percentage of term pregnancies that are breech
3-4%
criteria for safe breech delivery
lack of uterine or fetal anomalies
estimated fetal weight between 2500-4000
frank or complete breech (not footling)
OB with appropriate training and experience
criteria for defining 39w
36w from positive preg test
+FHR by doppler for 30 weeks
US in first trimester confirms 39w EGA
2nd trimester US/history c/w 39w EGA
risk of uterine rupture with TOLAC
1) previous LTCS
2) previous classical
3) previous uterine rupture
4) misoprostol use
1) 1%
2) 10%
3) 5%
4) 15%
high and low cut offs of MOM for the normal range of MS-AFP
0.5-2.5 is the normal range
differential diagnosis for elevated MS-AFP
open NTDs
incorrect dating
Multiple gestation
unidentified IUFD
open Abdominal wall defects
fetal aneuploidy
possible placental abnormality
maternal ovarian tumor
unexplained elevated AFP consequences and management
term IUFD
IUGR
SIDS
preeclampsia
PTD
close monitoring and surveillance, ANT with serial growth US, consult MFM, notify peds
fragile x premutation counseling
refer to genetic counseling
increased likelihood of having a baby that is affected of developmental delay
CVS/amnio is possible
She is at increased risk premature ovarian failure
define
first
second
3a
3b
3c
4th degree tear
first: perineal skin only
2nd: perineum involving muslces but not anal sphincter
3a: <50% of external anal sphincter torn
3b: >50% of external anal sphincter torn
3c: both external anal and internal anal sphincter torn
4: anal epithelium
risk of untreated hypothyroidism
impact on fetal growth, fetal thyroid development, fetal neuro development
who should you do early GDM screen on
overweight or obese (BMI 25 or greater) PLUS
-physical inactivity
-first degree relative with diabetes
-high risk race or ethnicity (AA, latino, native american, asian american, pacific islander)
-previous infant weight 4000g
-HTN (140/90 or on therapy for HTN)
-HDL < 35, TG >250
-A1c greater than or equal to 5.7
-other clinical conditions associated with insulin resistance (pre pregnancy BMI >40, acanthosis nigricans)
-hx of CVD
Normal pH of vaginal secretions
Amniotic fluid pH
normal vaginal pH 3.8-4.5
amniotic fluid 7.1-7.3
Risk of accreta with previa and prior CS
First CS- 3%
Second CS- 11%
Third CS - 40%
4th CS -61%
5th CS- 67%
Subgaleal hematoma
Vs cephalohematoma
Beneath the connective tissue of scalp, above the skull, no boundaries
Goes over the suture lines. Not confined
Cephalohematoma, one layer below. Under the periosteum, lining of outer part of bone, above the bone itself, contained by periosteum. Doesn’t cross suture lines.
Types of vasa previa
1) velamentous cord
2) succenturiate or multi lobed placenta
AFE
Risk factors
Presentation
Treatment
Amniotic fluid into maternal circulation- inflammatory mediators cause anaphylactic reaction
Things that overly distend- ama,
multiparity, preeclampsia, eclampsia, DM, polyhydramnios
Labor risk factors- precipitous labor, placental abruption, cervical lac, uterine rupture
Three phases
1) pulmonary and systemic hypertension with severe pulmonary vasoconstriction - respiratory distress and hypoxemia leading to altered mental status and hemodynamic collapse
2) decrease SVR and LV stroke work
3) lung injury, coagulopathy, DIC
Often results in pulmonary HTN, right sided heart failure, global myocardial depression
Treatment- oxygenation and circulatory support with blood products, limited use of IV fluids, vasopressors, and if necessary bypass. If occurs before delivery- deliver the baby
2 hour OGTT cut offs
75 gram load
fasting: 92
1 hour: 180
2 hour: 153
postpartum GDM eval
75 gram 2 hour OGTT and fasting plasma glucose at 4-12 weeks postpartum
Normal: fasting less than 100
2 hour < 140
how to calculate apgar scores
heart rate-: 0= absent, 1: <100, 2: >100
respiratory rate: 0=absent, 1: slow, irregular, 2: good, crying
muscle tone: 0= flaccid, 1: mild flexion, 2: active motion
reflex irritability: 0= no response; 1: grimace; 2: vigorous cry
color: 0= blue, pale; 1: pink body, blue extremities; 2: completely pink
Score of 0,1, or 2
Zika virus
fetal/maternal se
transmission
microcephaly
most infected adults are asx. common sx: fever, rash, arthralgia, myalgia
transmission from aedes species of mosquito, human to human
zika prevention, diagnosis, and treatment
female should delay conception for 8 weeks
male should wait 3 months if exposed
dx: IgM Ab serology and ZIKV NAAT testing (blood and urine) for pregnant women with exposure and sx within the last 12w
NAAT testing 3 times during preg for asx patient with ongoing exposure (live in endemic area)
serial us to assess for anatomy and growth
how to calculate the number of rhogam vials needed
KB% of fetal RBCs x 50 / 30
KB% of fetal red blood cells x 50 = volume of bleed
Cardinal movements of labor
ED FIRE REX
Engagement
Descent
Flexion
Internal rotation
Extension
External rotation
Expulsion
Magnesium toxic levels
Loss of reflexes at 10 mg/dL
respiratory arrest at 16
Cardiac arrest at 22
What should you avoid in patients with myasthenia gravis
Magnesium
Use phenytoin or diazepam
If a patient is on magnesium and has a seizure, what do you do
Give a second bolus of 2g of mag
Then lorazepam 4mg IV over 2 min
Then diazepam 5-10 my IV
Vasa previa delivery timing
Admit to hospital 30-34 weeks
Deliver 34-35w6d
delivery timing for mo/di isolated FGR
32-34 6/7
Dka in Pregnancy
Get icu and MFM involved
Diagnosis- check beta hydroxy butyrate. Elevated anion gap greater than 20. Eval for cause like infection
Check ABCs
Monitor abgs and lytes
IVF switch from NS to D5-NS when you get to glucose of 200
Potassium- when you give insulin potassium goes intracellular. If less than 3.3 hold insulin.
If bicarbonate is less than 7 then correct it
Insulin- weight based insulin. Regular insulin- loading 0.1units/kg then maintenance of .1u/kg/hr then decrease to 0.05 when glucose less than 200
DO NOT DELIVER THE PATIENT WHILE IN DKA. Usually resolves after DKA. Patient not stable if you take her to the operating room.
Thyroid storm treatment
PTU: 1 gram loading PO then 200 mg q6h
Iodine: 1-2 hours later. Lugols 10 drops q8h or sodium iodine 1g q8h
Propranolol- 20 to 80 mg po or IV to control tachycardia
Steroids: hydrocortisone 100 mg IV every 8 hours or dexamethasone 2mg IV every 6 hours
IV hydration with D5 NS
Fetal varicella concerns
SAB
IUfD
Varicella embryopathy- skin scarring, limb hypoplasia, chorioretinitis, microcephaly
Exposure 13-20 weeks- 2% risk. After that very low risk
Varicella diagnosis
Clinical
Pcr of vesicular fluid or swab
Elisa of VZV igM or igG
Listeria
Diagnosis
Treatment
Asymptomatic- observe for symptoms for two months
Mild symptoms and no fever- observe or test
Febrile +|- symptoms- test and treat
Test with blood culture
Treat with high dose IV amp for 14 days. If PCN allergy use trimethoprim with sulfamethoxazole
Sx- mild GI or flu symptoms
death of one twin after 14w
Risk of neuro injury in surviving twin
monochorionic twins
cotwin death 15%
cotwin neuro abnormality: 18%
death of one twin after 14w
Risk of neuro injury in surviving twin
dichorionic twins
co twin death: 3%
co twin neuro abnormality: 1%
oligohydramnios differential
DRIP TAP
Drugs
ROM
IUGR
Placental insufficiency
Twins
abruption
post dates
Also add congenital anomalies
