- Fetal Upturned Nose
- IgA Nephropathy in Pregnancy
- Umbilical vein varix
- Timing of Cranial Markers in Open NTD
- Real world experience Open Neural tube defect and Brain Signs
- Real world experience First Trimester Megacystis – Management
- Real world experience Fetal Megacystis
- Abnormal facial profile
- Azygous Vein & ARSA
- Blakes Pouch Cyst
- Absent nasal bone (ANB)
- Choroid plexus cysts
- Chronic placental abruption
- Fetal Alcohol Syndrome
- Placenta-First Risk Stratification
- AVSD
- Blakes Pouch Cyst
- Confined Placental Mosaicism
- Echogenic Bowel
- Fetal Anemia
- Fetal Club Foot
- Fetal Mild Micromelia
- Hypochondroplasia – Mild Micromelia
- Hypoplastic Nasal Bone
- IgM IgG IgG Avidity
- Increased Nuchal Translucency
- Isotretinoin in Pregnancy
- Partial agenesis of corpus callosum
- PGT A
- PGT-A Mosaicism to CPM
- Placenta First - CPM
- Radiation exposure during pregnancy
- Real world Chorionic bump experience
- Real world Fetal Isotretinoin exposure
- Real world Increased Nuchal Translucency & Genetic RISK
- Real world Renal Pyelectasis
- Real world Transient NT & Cystic Hygroma
- Real world Transient NT
- Renal Pyelectasis or Extra Renal Pelvis
- Right And Double Aortic Arch
- Short Femur Length Foot FL ratio
- Y Microdeletion
- CCAM CPAM
- Coffin–Siris syndrome
- Congenital CMV Infection
- Increased NT and Localized CHAOS
- Indomethacin and Reduction for AFI
- Atrioventricular septal defect (AVSD)
- Choledochal cyst & Cystic biliary atresia
- Duodenal Atresia
- Fetal atrial bigeminy
- Fetal Dilated stomach
- Mutation Types in DMD
- Risk of rubella in nonimmune pregnant woman
- Salt-losing nephropathy
- Syndromic Cystic biliary atresia
- TGA DORV TOF CCTGA
- Unilateral echogenic kidney with polyhydramnios
- Unilateral renal agenesis, Ectopic, Cross fused kidney
Increased first-trimester nuchal translucency (NT) with normal genetics can be an early sign of airway obstruction, including left-sided bronchial obstruction or evolving CHAOS, though it is not specific.
Airway obstruction can cause increased NT
In Congenital high airway obstruction syndrome or proximal bronchial obstruction:
Airway blockage → lung fluid trapped → lung expansion → venous compression → lymphatic congestion → increased NT.
Also:
- Impaired venous return to heart
- Early mediastinal compression
- Evolving hydrops physiology
ALL this can happen before obvious lung findings appear.
First-trimester NT in airway obstruction
11–13 weeks
- Increased NT
- Normal karyotype
- No obvious thoracic mass yet
16–20 weeks
- Echogenic enlarged lung
- Mediastinal shift
- Bronchial dilation
Later
- Stable or progressive airway obstruction pattern
Increased NT with normal genetics can be the earliest clue to bronchial obstruction or CHAOS spectrum.
Left-sided localized CHAOS
Classic Congenital high airway obstruction syndrome:
- Bilateral lung enlargement
- Tracheal dilation
- Inverted diaphragm
Localized bronchial obstruction behaves like: Segmental or unilateral CHAOS
- Bronchial atresia
- Mucus plug obstruction
- Localized airway obstruction
- Increased NT (early)
- Normal genetics
- Later whole unilateral lung hyperinflation
- Mediastinal shift
- No cystic lesion
This becomes highly suggestive of: Proximal bronchial obstruction
Possibly:
- Congenital bronchial atresia
- Mucus plug–related obstruction
Other causes of increased NT with normal genetics
Cardiac defects
- Outflow tracts
- Venous return
Lymphatic abnormalities
- Cystic hygroma
- Lymphatic dysplasia
Thoracic compression lesions
- CPAM
- Sequestration
Early hydrops physiology
- Anemia
- Infection
Key diagnostic clues
A. Dilated bronchus
Very important sign, If present: strongly supports bronchial obstruction.
B. Tracheal size
- Normal → localized obstruction
- Dilated → CHAOS spectrum
Role of MRI
- Show level of obstruction
- Confirm bronchial dilation
- Differentiate mucus plug vs structural atresia
- Assess lung volume
Prognostic implications
Depends mainly on:
- Hydrops
- Progression
- Lung compression severity
If increased NT was:
- Transient
- Genetics normal
- Later unilateral lung enlargement seen
This sequence is: highly compatible with evolving airway obstruction spectrum.
Based on:
- Early increased NT
- Normal genetic testing
- Whole left lung hyperinflation
- Dextroposition
Most coherent explanation: Left main bronchial obstruction (possibly mucus plug related)
Rather than:
- Classic CPAM
- Classic bilateral CHAOS
Increased NT with normal genetics can be an early manifestation of airway obstruction, including left-sided bronchial obstruction or localized CHAOS, especially when later imaging shows whole unilateral lung hyperinflation with mediastinal shift.