Question

Which statement regarding the development of the respiratory system is a high priority for the nurse to understand?

a.The respiratory system does not begin developing until after the embryonic stage.
b.The infant's lungs are considered mature when the L/S ratio is 1:1, at approximately 32 weeks of gestation.
c.Maternal hypertension can reduce maternal-placental blood flow, accelerating lung maturity.
d.Fetal respiratory movements are not visible on ultrasound scans until at least 16 weeks of gestation.

Answer 1

The nurse should understand that fetal lung maturity isn't indicated by an L/S ratio of 1:1 at 32 weeks gestation, but by sufficient development of alveolar precursors closer to the eighth month. Fetal respiratory movements are visible around week 20 or 21 on ultrasound scans.

Step-by-step explanation:

The correct statement regarding the development of the respiratory system that a nurse should understand is that the infant's lungs are considered mature when sufficient alveolar precursors have matured, which is not accurately represented by an L/S ratio of 1:1 at 32 weeks of gestation. In fact, surfactant levels are not generally adequate for effective lung compliance until about the eighth month of pregnancy. Furthermore, fetal respiratory movements can be observed around week 20 or 21 since this is when fetuses begin to inhale and exhale amniotic fluid, which may help tone the respiratory muscles in preparation for breathing after birth.