Amniotic fluid, amniocentesis

Question 1

Everything about Amniotic fluid

Answer 1

Question 2

Amniocentesis

• Features
• Functions

Answer 2

Question 3

Fetal lung immaturity assessment

Answer 3

Performed by measuring the pulmonary phospholipids or lamellar bodies, which enter the amniotic fluid from the fetal lungs after 28 weeks of gestation.

• The phosphatidylglycerol and a lecithin-to- sphingomyelin ratio greater than 2.0 are associated with minimal risk of respiratory distress in the neonate.
• US is now more commonly used due to low adverse effects.

Question 4

Therapeutic amniocentesis in polyhydramnios and TTTS

Answer 4

The primary role of a therapeutic amniocentesis has been in the management of polyhydramnios (excessive accumulation of amniotic fluid) and twin-twin transfusion syndrome.

• Polyhydramnios (deepest vertical pocket of amniotic fluid > 8 cm on US) can cause maternal respiratory embarrassment or premature labor may arise from lack of fetal swallowing or from excessive fetal urination.
• Twin-twin transfusion syndrome (TTTS) is a serious complication of monozygotic monochorionic twinning which shared placental blood vessels allow shunting of blood away from one twin (the donor) to the cotwin (the recipient).

Monozygotic twinning occurs when a single fertilized egg divides to form 2 embryos.

Question 5

Chromosomal abnormalities and sex-linked diseases

Answer 5

Fetal karyotype can be determined that can reveal Down’s sy, Turner’s sy, and various mosaics.

• Can determine fetal sex hence is useful in sex-linked disorders such as thalassemia, hemophilia, and Duchenne’s muscular dystrophy.

Question 6

Metabolic disorders

Answer 6

Includes Tay-Sachs disease and galactosemia that are diagnosed using fetal cells.