Fetopathology and developmental pathology of the embryo and fetus
Marta Ježová, Josef Feit et al.
+ Introduction
+ Using this atlas
+ Conditions of using this atlas
+ Technical notes
+ Hardware
+ Software
+ Virtual microscope, new interface
+ Virtual microscope interface for users
+ Scroll bars
+ Pohyb obrazem
+ Náhledové okno
+ Tlačítka v horní části okna
+ Aktivace šipek
+ Popis obrazu
+ Přepínání jazyka
+ Nastavení, kontextové menu
+ How to use the atlas
+ Navigating through the text pages
+ Controlling the pictures
+ Logos and labels
+ What will you need to use the atlas
+ Bugs, problems
+ Netscape
+ Microsoft Internet Explorer
+ Some other Internet resources concerning dermatopathology and pathology
+ Support
+ Support
+ Atlas of fetal pathology
+ Congenital malformations
+ Physiological developement of an embryo and fetus, growth and changes of the external shape
+ Congenital malformations and congenital anomalies
+ Basic terminology
+ Etiology of congenital anomalies (CA)
+ Environmental causes of congenital anomalies, congenital infections
+ Rubella
+ Cytomegalovirus
+ Syphilis
+ Toxoplasmosis
+ Diabetes mellitus (DM) and pregnancy
+ Diabetic embryopathy
+ Diabetic fetopathy
+ Genetic causes of congenital malformations
+ Chromosomal abnormalities
+ Down syndrome
+ Klinefelter syndrome
+ Turner syndrome
+ Patau syndrome
+ Edwards syndrome
+ Triploidy
+ Single gene disorders
+ Tuberous sclerosis
+ Miscellaneous malformation syndromes, sequences and associations, unclassified
+ Sirenomelia (Mermaid syndrome)
+ Hydrops fetalis
+ Immune hydrops (erythroblastosis fetalis, hemolytic disease of the newborn)
+ Nonimmune hydrops
+ Hygroma colli cysticum
+ Pierre-Robin sequence
+ Caudal regression syndrome (sacral agenesis)
+ VACTERL association
+ Pathology of twinning
+ Complications of monochorionic diamnionic placentation
+ Chronic twin transfusion syndrome
+ Acute twin-twin transfusion
+ Complications of monochorionic monoamnionic placentation
+ Congenital malformations in twins
+ Chorangiopagus parasiticus (acardius)
+ Pathology of higher multiple gestations: triplets
+ Monsters
+ Monstra duplicia
+ Gemini monochoriati inequales
+ Duplicitas symmetros
+ Asymmetric dual monsters
+ Monstra simplicia
+ Congenital malformations of individual organ systems
+ Congenital malformations of the central nervous system
+ Congenital malformations of the spinal cord
+ Spina bifida
+ Myeloschisis (rachischisis posterior)
+ Congenital malformations of the brain
+ Anencephaly
+ Iniencephaly
+ Encephalocele
+ Arnold-Chiari malformation
+ Disorders of formation of the structures derived from the mediobasal prosencephalon
+ Migration disorders
+ Destructive lesions of fetal brain (disruptions)
+ Porencephaly
+ Hydranencephaly
+ Hydrocephalus
+ Dandy-Walker malformation
+ Intracranial non-neoplastic cysts
+ Arachnoid cyst
+ Neuroepithelial cyst
+ Congenital malformations of the respiratory system
+ Congenital cystic adenomatoid malformation (CCAM)
+ Lobar sequestration
+ Congenital lobar emphysema
+ Pulmonary hyperplasia
+ Pulmonary hypoplasia
+ Congenital pulmonary lymphangiectasia
+ Diaphragm and congenital malformations
+ Congenital malformations of kidneys and efferent urinary tracts
+ Renal agenesis
+ Variations of shape and position of the kidneys
+ Renal cystic disease
+ Infantile polycystic kidneys (ARKPD)
+ Renal dysplasia
+ Adult polycystic kidneys (ADPKD)
+ Autosomal dominant polycystic kidney disease in infant and fetus
+ Lower urinary tract obstruction
+ Posterior urethral valves
+ Congenital tubular renal dysgenesis
+ Urinary bladder
+ Hypospadia
+ Congenital malformations of genital system and somatosexual congenital disorders
+ Somatosexual disorders
+ Somatosexual disorders with normal karyotype
+ Pseudohermaphroditism masculinus
+ Androgen insensitivity syndrome, testicular feminization syndrome, female XY
+ Pseudohermaphroditism femininus
+ Congenital adrenal hyperplasia
+ Somatosexual disorders with pathologic karyotype
+ Congenital malformations of female genitalia
+ Congenital malformations of the internal genitalia
+ Congenital malformations associated with congenital malformations of urinary system
+ Congenital malformations of the vulva
+ Congenital malformations of the male genital organs
+ Cryptorchidism
+ Congenital malformations of penis and scrotum
+ Smith-Lemli-Opitz syndrome (SLOS)
+ Congenital tumors
+ Sacrococcygeal teratoma
+ Congenital cardiac rhabdomyoma
+ Congenital heart defects
+ Defects of heart septum
+ Atrial septal defects
+ Ventricular septal defects
+ AV septal defects
+ Anomalies of the great arteries
+ Transposition of the great arteries
+ Truncus arteriosus
+ Double-outlet right ventricle
+ Malformations of the valves
+ Tricuspid atresia
+ Stenosis and atresia of the mitral valve, the hypoplastic left heart syndrome
+ Stenosis of the pulmonary artery
+ Pulmonary atresia with intact ventricular septum
+ Tetralogy of Fallot
+ Aortic stenosis
+ Malformations of the aortic arch system
+ Persistence of ductus arteriosus
+ Coarctation of the aorta
+ Interruption of the aortic arch
+ Right-sided aortic arch
+ Malformations of the venous system
+ Anomalies of situs and heart position
+ Di George syndrome
+ Congenital malformations of the gastrointestinal tract
+ Oral cavity and the palate
+ Cleft lip and palate
+ Congenital defects of the esophagus
+ Atresia
+ Congenital esophagus stenoses
+ Congenital malformations of the stomach
+ Congenital malformations of the intestines
+ Atresia
+ Malrotation of the intestine
+ Remnants of the omphalomesentric duct
+ Anorectal malformations
+ Duplicatures
+ Defects of the abdominal wall
+ Omphalocele
+ Gastroschisis
+ Limb-body wall complex
+ Pentalogy of Cantrell
+ Developemental anomalies of the skeleton
+ Defects of growth of tubular bone and/or spine
+ Thanatophoric dysplasia
+ Diastrophic dysplasia
+ Abnormalities of density of cortical diaphyseal structure or metaphyseal modeling
+ Osteogenesis imperfecta
+ Limb malformations
+ Terminal transverse limb defects
+ Radial ray defects
+ Finger anomalies
+ Club foot
+ Constriction (amniotic) band syndrome
+ Placental inflammation
+ Ascending infections
+ Placental inflammation, acute
+ Hematogenous infections
+ Fetomaternal listeriosis
+ Pathology of the fetal membranes
+ Amniotic band syndrome
+ Meconium staining
+ Candida infection of the placenta
+ Pathology of the placenta
+ Normal placenta
+ Extrauterine gravidity
+ Gestational trophoblastic disease (GTD)
+ Hydatidiform mole
+ Complete mole
+ Partial mole
+ Invasive mola (mole proliferans, mole destruens)
+ Gestational choriocarcinoma
+ Placental site trophoblastic tumor
+ Placenta and major chromosomal abnormalities
+ Hydropic placenta
+ Pathology of the umbilical cord
+ Abnormal length
+ Short cord
+ Long cord
+ Insertion abnormalities
+ Abnormal coiling
+ Umbilical vessels pathology
+ Umbilical cord accidents which compromise the blood flow
+ Thrombosis of umbilical blood vessels
+ Umbilical cord inflammation
+ Acute funisitis
+ Subacute necrotizing funisitis
+ Miscellaneous rare cord lesions
Down syndrome

Full trisomy 21 in 95% of the cases.

Clinical signs
  • incidience 1 : 700 livebirths
  • the indicence is directly related to advanced maternal age
  • increased risk of fetal demise
  • mental retardation
  • intrauterine growth retardation, short stature, obesity
  • high relative risk of acute leukemia in the first 5 years of life
  • immunodeficiency, increased risk of bacterial pneumonia in particular
  • there is a shortened life expectancy even if the the survival in individuals with Down syndrome has significantly improved, the estimated life expectancy nowadays is near 60 years
  • congenital heart diseases are major cause of early mortality, 10% of these infants die within the first year of life nowadays
Macroscopic appearance
  • Phenotypic features in a full term infant: brachycephaly, microcephaly, flattened occiput, flat face, upslanting palpebral fissures, epicanthic folds, small nose with broad and flat nasal bridge, open mouth with protruding tongue, slightly abnormal ears, fifth finger clinodactyly, single palmar crease(simian crease).
  • Mongoloid face and brachycephaly cannot be identified in a fetus. Fifth finger clinodactyly and single palmar creases can be easily recognized even in a second trimester fetus. Nuchal edema can be seen in a small fetus, hydrops is rare.
  • Cardiovascular system malformations: in approximately 40% of the cases:
    • AV septal defect, common atrioventricular canal
    • ventricular septal defect
    • atrial septal defect
  • CNS: the brain has abnormal shape, abnormal gyri in the temporal lobe and decreased weight
  • Thymus: hypoplasia, cystic degeneration of Hassall's corpuscles; these findings are probably related to abnormal immune system
  • Gastrointestinal system malformations:duodenal atresia, umbilical hernia.
  • Ultrasonographic findings in trisomy 21:
    • 1st trimestr ultrasonography:
      • Nuchal translucency is subcutaneous accumulation of fluid behind the fetal neck. It looks like a small black space under the fetal neck skin on ultrasonound examination. All major chromosomal defects (trisomy 21, 13,18, Turner syndrome, triploidy) are associated with increased nuchal translucency thickness. The optimal gestational age for measurement of nuchal translucency (NT) is between 11  —  14 weeks. NT greater than 2,5 mm substantially increases the risk of chromosomal abnormality in the fetus. During the second trimestr the translucency usually disappears, sometimes it evolves into either nuchal edema or nuchal cystic hygroma
      • Absent nasal bone: The fetal nasal bone can be visualized by ultrasonography as early as at 11 – 14 weeks. Absent fetal bone (because of delayed ossification of the bone) is detected in approximately 70% of trisomy 21 fetuses. In chromosomally normal fetuses the prevalence of absent nasal bone is less than 1%.
      • Up to 90 % of fetuses with trisomy 21 can be detected in early gestation if the ultrasonographic and biochemical screening are combined.
    • 2nd trimestr ultrasonography
      • Nonstructural markers of chromosomal abnormality:
        • nuchal edema
        • absent nasal bone or nasal bone hypoplasia
        • short limbs (femus, humerus)
        • mild ventriculomegaly
        • mild pyelectasia
      • structural defects:
        • cardiac defects
        • omphalocele
        • duodenal atresia

M. Down, ultrasound (72952)

M. Down, 14. week (73971)

M. Down, 22. week (73972)

M. Down, fetus (72097)

M. Down, AV septal defect (72499)

M. Down, hydronephrosis (72962)


Down syndrome, 1st trimester of gravidity: absence of nasal bone, nuchal edema: M. Down, 1st trimester, Ultrasound, video (72952)

Down syndrome, fetus 14-week: M. Down, Macro, autopsy (73971)

15 – week fetus, trisomy 21; marked nuchal edema: m. Down, nuchal edema, Macro, autopsy (72967)

Downův syndrom, fetus 22-week: M. Down, Macro, autopsy (73972) M. Down, Macro, autopsy (73973)

Down syndrome, fetus: Down syndrome, Macro, autopsy (72097) Down syndrome, Macro, autopsy (72098)

Down syndrome, fetus, hand with single palmar crease (simian crease), clinodactyly of the little finger: m. Down, simian crease, Macro, autopsy (72389) m. Down, Macro, autopsy (72390)

Down syndrome, AV septal defect (complete AV canal): AV canal, view from the left ventricle, fetus 18th week of gestation, Macro, autopsy (72501) AV canal, septum with the defect, Macro, autopsy (72500) AV canal, view from the right ventricle, fetus 18th week of gestation, Macro, autopsy (72499)

Stillborn 40-week infant, trisomy 21; intrauterine growth retardation (weight 2600 g), external features  —  flat face, small nose, broad flat nasal bridge; severe maceration: m. Down, intrauterine death, maceration, Macro, autopsy (72963) m. Down, intrauterine death, maceration, Macro, autopsy (72964) m. Down, intrauterine death, maceration, Macro, autopsy (72965)

Male newborn, trisomy 21. Hydroureter (extremely dilated left ureter), bilateral renal dysplasia. The child died of pulmonary hypoplasia: m. Down, hydronephrosis, Macro, autopsy (72962)

M. Down, duodenal atresia: m. Down, duodenal atresia, Macro, autopsy (74369) m. Down, duodenal atresia, Macro, autopsy (74370) m. Down, duodenal atresia, Macro, autopsy (74371) m. Down, duodenal atresia, Macro, autopsy (74372) m. Down, duodenal atresia, Macro, autopsy (74373)

Case study
Morbus Down
Marta Ježová
  • 46 – year-old woman, third gravidity
  • Prenatal ultrasound examination (16 weeks):
    • nuchal edema 5 mm
    • mild hydrops
    • absent nasal bone
    • normal anatomy of the heart
  • Fetal karyotype (QF-PCR): trisomy 21

Note: QF-PCR  —  quantitative fluorescence polymerase chain reaction is a method for rapid detection of the most common chromosomal abnormalities.

Macroscopic appearance
  • female fetus, 17. w.g.
  • nuchal edema
  • tiny nose

Nuchal edema (72966)


17 – week female fetus, nuchal edema: m. Down, nuchal edema, Macro, autopsy (72966)

Prenatal ultrasound, video: nasal bone is missing: M. Down, 2nd trimester, Ultrasound, video (72953)


Thymus may be hypoplasic with lymphocyte depletetion, large cystic Hassals corpusles with calcification seem to be characteristic for Down syndrome.


Thymus, macerated fetus with Down syndrome: m. Down, calcification of the thymus (abortion), HE 40x (71990)