Fetal Anomalies / Ultrasound

Question 1

Anencephaly (Risk Factors

Answer 1

Open NTD
1:1000 in US
Multifactorial
Teratogens (Folic Acid Deficiency, heat, irradiation, EtOH, Aminopterine, VPA, obesity)

Question 2

Anencephaly Prevention

Answer 2

Recurrence Risk (2-3%)
Prevention:
Low Risk: Folic Acid 0.4mg daily
High Risk: Folic Acid 4mg QD 1 month prior to 1st Trimeseter)

Question 3

Omphalocele

Answer 3

Midline defect
Covered by membrane
50% have other anatomic abnormalities
Recommend Karyotype

Question 4

Lemon Sign

Answer 4

Most likely associated with spina bifida

Question 5

NTD (Epi)

Answer 5

1-2:1000 pregnancies
50-55% spina bifida
45-50% anencephaly
<5% encephaloceles

Multifactorial
Recurrence Risk 2-3%

Question 6

NTD Etiology

Answer 6

Multifactorial

• Heat, irradiation, VPA, carbamazepine, aminopterie
• Obesity, DM, Folic Acid deficiency

Question 7

NTD US findings

Answer 7

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

Question 8

Banana Sign

Answer 8

Distorted cerebellum
Obliteration of cisterna magna
2/2 Arnold-Chiari malformation
- 95% of effected fetuses with NTD

Question 9

Echogenic Bowel

Answer 9

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

Question 10

Duodenal Atresia

Answer 10

1:10000
Mostly sporadic
~ with other anomalies
1/3 have Trisomy 21
- Polyhydramnios

Workup:

• Offer amnio
• recurrence <=1%

Question 11

Most accurate single measure of GA

Answer 11

BPD

Question 12

Cystic Hygroma

Answer 12

Most commonly associated with Turner Syndrome

Question 13

Most Common diagnosis in male fetus with hydrnoephrosis, dilated bladder

Answer 13

Posterior Urethral Valves

Question 14

Most common cause of echogenic kidneys

Answer 14

AR PCKD.

• Associated wtih oligo and pulmonary hypoplasia
• May also see hepatic fibrosis

Question 15

Cardiac Anatomy

Answer 15

Moderator Band - Thickening of the interventricular septum at level of apex. Distinguishes orphological right ventricle (in R ventricle

Question 16

Holoprosencephaly

Answer 16

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

Question 17

Ventriculomegaly

Answer 17

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)

Question 18

Femoral Hypoplasia Unusual Facies Syndrome

Answer 18

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

Question 19

IUD in early pregnancy

Answer 19

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

Question 20

Bilateral Renal Agenesis

Answer 20

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