Obstetrics Flashcards
menstrual age:
embryologic age + 14 d
embryo
0-10 wks (menstrual age)
fetus
> 10wks (f after e)
threatened abortion
bleeding w/ closed cervix
inevitable abortion
cervical dilation and/or placental and/or fetal tissue hanging out
incomplete abortion
residual products in uterus
complete abortion
all products out
missed abortion
fetus dead, still in uterus
intradecidual sign-when
early gest sac, 4.5 wks
double decidua sac sign-layers
decidua capsularis (closest) and basalis/vera (myometrial) decidua peritalis-opposite wall
when do amnion and chorionic mems fuse?
14-16 wks
etiology of amniotic band syndrom
amnion disrupted bf 10 wks –> fetus cross into chorionic cav and get tangled in fibrous bands
YS abnormal morphology
- 6 < x < 3 mm
- calcified
- solid
normal YS-size, consistency, appearance
- 3-6 mm, cystic
- 5.5 wks
- in chorion connect to umb via vitelline duct
double bleb sign
-YS and Amn sac with emb in middle
Summary of sonogram antenatal findings
0-4.3 weeks: no ultrasound findings
4.3-5.0 weeks:
possible small gestational sac
possible double decidual sac sign (DDSS)
possible intradecidual sac sign (IDSS)
5.1-5.5 weeks:
gestational sac should be visible by this time
5.5-6.0 weeks
yolk sac should be visible by this time
gestational sac should be ~6 mm in diameter
double bleb sign
>6.0 weeks
fetal pole may be identifiable on endovaginal ultrasound (1-2 mm)
fetal heart rate (FHR) should be ~100-115 bpm
gestational sac should be ~10 mm in diameter
6.5 weeks
crown rump length (CRL) should be ~5 mm
7-8 weeks
CRL is between 11-16 mm
cephalad and caudal poles can be identified
8-9 weeks
CRL is between 17-23 mm
limb buds appear
head can be seen as separate from the body
9-10 weeks
CRL is between 23-32 mm
fetal heart rate 170-180 bpm
fetal movement can be seen
a round hypoechoic structure in the fetal brain represents a developing embryonic/fetal rhombencephalon
nuchal translucency may begin to be seen
pseudogestational sace
ectopic
when should you see YS-wk, size, b-hcg
~5.5 wks, GS ~8mm, b-HCG 5000 mIU/L
implantation bleed
small subchor hem at chorion/endom attach
subchorionic hemorrhage-what matters
- fetal demise-% placental detach; hematoma >2/3 chorion circumference
- (+) maternal age worse outcome
criteria fetal demise-diagnostic
- CRL 7mm, ø HR
- GS >25mm, ø embryo
- ø HR 14+ days s/p GS
- ø HR 11+ d s/p GS + YS
criteria fetal demise-suspicion
- ø embryo 6+ wks after last menstrual pd
- GS 16-22mm w/o emb
- ø HR 13 days s/p GS
- ø HR 10 d s/p GS + YS
pregnancy of unknown location
+b-hcg, nothing in uterus
1) normal
2) occult ectopic
3) complete miscarriage
order of EP PPV
- live adnexal preg-100%
- mass-75-80%, +FF-97%
- free fluid-70% (inc if fluid echo)
fetal growth measurement
- BPD-thal, outer to inner. Aff by head shape
- HC-same slice. Less off by head shape
- AC-umb v and LPV
- FL-long dimension of shaft
- composite for GA during 2nd & 3rd TM
Symmetric vs Asymm IUGR
- S=small head, skinny body, same thru out pregn, sylph, scotch, some extra chroms
- Asymm-abd small, aching belly (malnutrition), abn high BP, Alastic skin (Ehler Danlos), Asymm time interval (3rd TM)
Gestational accuracy throughout pregn
- 1st TM CRL-0.5 wks
- 2nd TM Composite GA- 1.2 wks
- 3rd TM CGA-3.1 wks
umbilical artery systolic/diastolic ratio
2-3 @ 32wks
-should not be more than 3 at 34wks
biophysical profile to assess acute and chronic hypoxia.
- score 2 points if N, total 8-10=N
- amn fluid-1 pocket >2cm in vertical plane. For chronic hypoxia
- fetal tone-1 ep extension from flexion. For acute hypoxia.
- fetal breathing-1 episode breathing motion ~30s. For acute hypoxia.
- non stress test-2+ fetal heart acc 15+BPM, 30+s-For acute hypoxia.
amniotic fluid index
- vertical heigh of deepest fluid pocket in each quadrant of uterus, sum 4 measurements
- N 5-20
- oligo <5
- poly->20cm OR single pocked >8
variant placental morphology
bilobed
succenturiate
circumvallate
A bilobed placenta also referred to as bipartite placenta, is a variation in placental morphology and refers to a placenta separated into two near equal-sized lobes. If more than two lobes are present, it is termed a trilobed, four-lobed and so on. If the second lobe is smaller than the main lobe (with the umbilical cord insertion), then the smaller lobe is termed a succenturiate lobe.
A succenturiate lobe is a variation in placental morphology and refers to a smaller accessory placental lobe that is separate to the main disc of the placenta. There can be more than one succenturiate lobe.
Circumvallate placenta refers to a variation in placental morphology in which, as a result of a small chorionic plate, the amnion and chorion fetal membranes ‘double back’ around the edge of the placenta.
placental thickness abN
too thin <1cm
too thick >4cm
placental abruption-clinical pres
painful
placental previa
- painless
- low lying (w/I 2 cm), marginal, complete, central
New revised classification with 3 categories only
1) Placenta previa (PP): Placenta covers internal os (IO)
2) Low-lying placenta (LLP): Placenta edge ≤ 2 cm from IO
3) Normal: Placenta edge > 2 cm from IO
* Avoid terms marginal or partial PP (deemed confusing)
placental creta types
accreta-through myom
increta- less through myom
percreta-transmural, serosal breach
placenta chorioangioma
hamartoma near cord insertion
- flow w/I mass pulsating at FRH (perfused by fetal circulation)
- compl: >4 cm or choraniomatosis (mult)-sequester platelets, cause hydros (high output failure)
placenta chorioangioma vs hematoma
chorioangioma has pulsating doppler flow
abn umbilical cord insertions
- velamentous
- marginal
- vasa previa
In a velamentous cord insertion, the umbilical cord inserts into the fetal (chorio-amniotic) membranes outside the placental margin and then travels within the membranes to the placenta (between the amnion and the chorion).
vasa previa
fetal vess cross (or almost cross) internal cervical os caused by velamenetous insertion or placental succenturiate lobe
- type 1-conn to velamentous cord insertion w/I main placental body
- type 2-conn to bilobed placenta or succenturiate lobe, type TWO att to TWO lobes
nuchal cord
wraps around fetus neck
umbilical cord cyst
- omphalomesenteric duct=per
- allantoic = central
- if persist into 2/3rd TM–> trisomy 18/13
nuchal translucency
- Normal fluid filled SQ space at back of fetal neck
- 9-12 wks (CTC), 11-15wk (FTC), CRL 45-85 mm
- N=<3 mm
- neutral neck, nasal bone seen, mid sag, well delineated skin edge
*combined w/ maternal serum to calculate overall risk of T21
chiari II findings
- banana (loss of normal bilobed cerebellum)
- lemon (flat/concave frontal bone)
ventriculomegaly on sonogram
> 10mm
-dangled choroid off the wall >3m
choroid plexus cyst
- usually means nothing
- T18, 21, turners, klinefelter
facial cleft
MC fetal facial anomoly
- 30%=chromosomal anomaly
- 80% also have cerebral palsy
echoogenic intracardiac focus
normal Ca of papillary m (LV)
-T21, 13
abN heart rates
- <100
- >180
echogenic bowel
should be same as liver
->bone=bad
short femur
<5th percentile
-skel dysplasia
incompetent cervix
endocervical canal <2.5 cm in length
-ass w/ high risk premature delivery
Cervical insufficiency (CI): Inability of cervix to retain pregnancy in absence of contractions or labor Clinical diagnosis
Short cervix: Cervical length (CL) < 10th percentile for gestational age
Sonographic observation; < 25 mm at < 24 weeks
Img: Dilated internal os (IO): Measure anterior-posterior diameter
things that grow in a pregnant person
- babies
- splenic a aneurysms
- renal AMLs
- fibroids
maternal complications
- hydronephrosis (R>L, mech compr.)
- fibroids-grow early via estrogen (shrink later via progesterone). infarct via compression of vess
- uterine rupture-3rd TM at site of prior c-section
- HELLP
- Peripartum cardiomyopathy-last mo-5mo’s pp
- sheehan syndrome-pit hem
- -ovarian v thrombophlebitis-pp fever
- retained products
- endometritis
categorizing multiple gestations
Dichorionic Diamniotic-separate or fused placentas
Monochorionic, diamniotic
mono/mono
differentiating mnochorionic from dichorionic gestation
membrane >4mm=di (made of 4 layers)
- twin peak sign-btw di/di
- T-sign-thin mem=mono
twin gestation complications to know
- twin twin transfusion syndrome (TTTS)-monochorionic. Disporoportionate bf
- twin reversed arterial perfusion syndrome (TRAP)-monochorionic
- Twin Anemia Polycythemia Sequence (TAPS)
- One Dead Twin
- Twin embolization syndrome-when 1 monochorionic twin dies; causes CNS, GI or Renal infarcts.
fetus papyraceous
pressed flat seat fetus
Fetus papyraceous is defined as a compressed fetus, the mummified, parchment-like remains of a dead twin that is retained in-utero after intrauterine death in the second trimester.
“combined test”
- NT, b-hcg, PAPP A
- sens 85%, FP 5%
“fully integrated test”
combined test < 14 wks + quad screen
- 15-19 wks
- 90-95% sens, FP 2.5-5%
“quad screen”
AFP
Estriol
B hcg
inhibin A
*performed at 15-19 wks
hydros fetalis
2+ fluid filled compartments in fetus
- subq edema=5mm+ thickness
- pleural effusions
- pericardial effusion
- ascites
- non-immune=70-90% (CV MC, 40%, hematologic, infection (herpes, parvovirus)
- Rh incompatibility no longer as common as it previously was
at what b-hcg should a GS be seen? YS?
2000 transvag
6500 transabd
YS: 5000
percentage breakdown of ectopic pregnancy locations
- 95% tubal- ampulla 70%, isthmus 12%, fimbria 11%
- 2-3% interstitial corneal
- <1% ovary
- c-section scar-rare
- abd-rare
recommendation for CPC in setting of amniocentesis
- no other risk factors-offer amniocentesis
- other RFs-amniocentesis recommended or encouraged
single umbilical cord
- single umbilical artery ass w/ fetal anomalies (CV MC) in up to 50%
- T13, T18
bladder flap hematoma
extraperitoneal blood collection at site of c-section incision, collecting btw bladder and AND LOWER uterine segment
