Fetal Anomalies / Ultrasound Flashcards
Anencephaly (Risk Factors
Open NTD
1:1000 in US
Multifactorial
Teratogens (Folic Acid Deficiency, heat, irradiation, EtOH, Aminopterine, VPA, obesity)
Anencephaly Prevention
Recurrence Risk (2-3%)
Prevention:
Low Risk: Folic Acid 0.4mg daily
High Risk: Folic Acid 4mg QD 1 month prior to 1st Trimeseter)
Omphalocele
Midline defect
Covered by membrane
50% have other anatomic abnormalities
Recommend Karyotype
Lemon Sign
Most likely associated with spina bifida
NTD (Epi)
1-2:1000 pregnancies
50-55% spina bifida
45-50% anencephaly
<5% encephaloceles
Multifactorial
Recurrence Risk 2-3%
NTD Etiology
Multifactorial
- Heat, irradiation, VPA, carbamazepine, aminopterie
- Obesity, DM, Folic Acid deficiency
NTD US findings
1) Lemon Sign
- 90% <24wk
2) Banana Sign:
- Cerebellar distortion
- 2/2 Arnold-Chiari malformation
- obliterated posterior fossa
3) Ventriculomegaly (least sensitivie
- 75% affected fetuses
Banana Sign
Distorted cerebellum
Obliteration of cisterna magna
2/2 Arnold-Chiari malformation
- 95% of effected fetuses with NTD
Echogenic Bowel
Echogenic Bowel: Same density as bone when gain turned down Associated with: - CF - CMV, - Downs - Aspiration of Blood
Wokrup:
- Offer amnio for karyotype, CMV PCR,
- Test fetal cells for CF
- Manage expectantly if no affected fetus
Duodenal Atresia
1:10000 Mostly sporadic ~ with other anomalies 1/3 have Trisomy 21 - Polyhydramnios
Workup:
- Offer amnio
- recurrence <=1%
Most accurate single measure of GA
BPD
Cystic Hygroma
Most commonly associated with Turner Syndrome
Most Common diagnosis in male fetus with hydrnoephrosis, dilated bladder
Posterior Urethral Valves
Most common cause of echogenic kidneys
AR PCKD.
- Associated wtih oligo and pulmonary hypoplasia
- May also see hepatic fibrosis
Cardiac Anatomy
Moderator Band - Thickening of the interventricular septum at level of apex. Distinguishes orphological right ventricle (in R ventricle
Holoprosencephaly
Rare, serious abnormality of embryonic forebrain
1. Alobar 2. Semilobar 3. Lobar
Lobar - most favorable
- Single sickle-shaped ventricle and bulb-like undivided thalamus
Hypertelorism (cytclopia), narrowed nasal bridge, abnormal proboscis, and clef lip/palate
- Strong association with Trisomy 13 an d 18
Offer genetic counseling and fetal karyotype
Ventriculomegaly
0.3-1.6 per 1000K live births
Etiology:
- 2/2 obstruction (60%)
- Impaired venous absorption (communicating hydrocephalus 40%)
Dx:
- Document widened atrium of lateral ventricle; shouldn’t exceed 10mm
Workup:
- Amnio (karyotype)
- Toxo, CMV syphilis,
- Family pedigree
- Look for other anomalies (spina bifida)
Femoral Hypoplasia Unusual Facies Syndrome
FHUFS (aka femoral-facial syndrome
- Craniofacial anomalies with femoral hypoplasia
~with IDDM (20% with diabetic Mothers)
Majority sporatic, cases of AD, no teratogens shown to contribute
PE:
- Up-slanting eyes, short nose with broad tip, elogated philtrum, thin upper lip, macrognathia, cleft lip, cleft palate, low-set ears
- Absent femurs +/- absent fibulas, usually bilateral and asymmetric
- Club foot/polydactyly, syndactaly, Spregel deformit, upper extrem hypoplasia, etc
- Rare
- Normal karyotype, nl lifespan/intelligenc
IUD in early pregnancy
Paragard: 0.6% failure in first year, 10-year failure 2.2%
Mirena 0.1% failure in first year, 1.1% failure over 7y
Px: Bleeding, pelvic pain, missing string
Workup:
- rule out ectopic
- remove IUD (through cervix vs IUD hook with US or hysterosocpy)
Cx: Septic AB< miscarriage, PTL
DOESNT CAUSE ANOMALIES
Bilateral Renal Agenesis
Constellation:
- Oligo, failure to find urinary bladder and failure to find nl kidneys
- Color dopper to see +/- renal arteries
Fetal MRI useful test in confirming renal ageensis
