Antepartum fetal surveillance

 Antepartum fetal surveillance (late pregnancy)

Objective;

Prevention of fetal death

Avoidance of unnecessary intervention

1.Clinical; clinical assessment of fetal growth

2. Biochemical; clinical assessment of fetal growth

3. Biophysical profile

Test for utero- placental insufficiency

Hypoxia; Metabolic acidosis - CNS depression - Change in fetal biophysical activity.

Biophysical test include;

1. Fetal movement count (FMC)

2. Cardiotocography

3. Non -stress test

4. Fetal biophysical profile (BPP)

5. Doppler ultrasound

6. Vibroacoustic stimulation test

7. Contraction stress test (CST)

8. Amniotic fluid volume

Amniocentesis in late pregnancy

1.Test for fetal pulmonary maturity

Confirmation of lung maturation

To reduce incidence of respiratory distress syndrome, caused by deficiency of pulmonary surfactant (synthesized by Type II alveolar cell.

Surfactant is packaged in lamellar bodies.

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Discharged in the lung alveoli

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Carried in pulmonary fluid

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Carried into amniotic fluid.

Risk of RDS is high for infants; delivered preterm (<37 weeks).

Assessment of fetal pulmonary maturity

• Estimation of pulmonary surfactant

Lecithin/Sphingomyelin (L/S ratio)

Amniotic fluid L/S ratio at 31-32 weeks ; 1

                                           at 35 weeks; 2

L/S ratio ≥ indicate, pulmonary maturity.

2. Shake test or bubble test (Clement's)

This test based on ability of pulmonary surfactant to form a foam or bubble.

Shaking for 15 second and inspect after 15 minutes.

Presence of a complete ring of bubbles at meniscus, if it is present, test is positive and indicates maturity of fetal lungs.

3. Foam stability index (FSI)

Based on surfactant detection by shake test.

Based on amount of surfactant present in amniotic fluid.

4. Presence of PG (Phosphatidyl glycerol) in amniotic fluid good indicator of fetal lung maturity.

5. Saturated Phosphatidyl choline

(Major components of pulmonary surfactant)

6. Fluorescence polarization

Measuring of fluorescence intensity.

7. Amniotic fluid optical density

8. Lamellar body

Storage form of surfactant

Lamellar body count >30,000 / µL indicates pulmonary maturity.

9.Orange color cells

Pregence of orange coloured cell in amniotic fluid; indicates pulmonary maturity

10.Amniotic fluid turbidity

During 1st and 2nd trimester

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Amniotic fluid is yellow

At term; turbid due to vernix.

2. Assessment of severity of Rh negative isoimmunization.

Done by amniocentesis

Higher level of bilirubin in Amniotic fluid; indicates severity of fetal hemolysis.

Rh incompatibility causes destruction of red blood cells.