We have been interested in thyroid hormone levels in amniotic fluid early in pregnancy and the consequences of delayed availability of these hormones on brain development . One of the commonest uses for an amnio, besides a genetic amnio is for determining the functional maturity of the lungs before a potential premature delivery. The lungs are ready to work in air when surfactant is produced in the pulmonary alveoli. Amniotic fluid can be assayed for surfactant, for products of surfactant, or for changes in physical properties of the fluid that attend the presence of surfactant. There are hormonal influences on the production of surfactant.
Surfactant tends to be produced a bit earlier in girls than in boys and when there is stress.
Artificial surfactant is given to infants who are delivered before functional maturation is complete. Amniotic fluid can be cultured or examined with light and electron microscopes for evidence of infection, and we have assayed amniotic fluid for lead, chromium, cadmium, selenium, other elements, drugs, and compounds with suspected environmental exposures.