Surfactant appears in amniotic uid at the gestational age of

Read below what Nelson has to say about the appearance of surfactant. "Surfactant is present in high concentrations in fetal lung homogenates by 20 wk gestation* but does not reach the surface of the lung until later. It appears in the amniotic uid between 28-32 wks. Mature level of pulmonary surfactant is usually present after 35 wks". Now I am leaving it to you to decide between 28 and 32 wks. I personally feel the answer should be 28 wks