Final answer:
Betamethasone is used in pregnant women to promote fetal lung development, reducing the risks associated with preterm birth. It does not prevent neonatal infections such as ophthalmia neonatorum, which requires other prophylactic measures.
Step-by-step explanation:
Betamethasone, when administered to pregnant women, is typically used to accelerate fetal lung development in cases where preterm birth is a risk. For the mother, betamethasone can cause side effects such as increased blood sugar levels, potential infection, and a brief drop in maternal platelet levels, but the emphasis is on the benefit to the fetus. In the neonate, betamethasone primarily helps by surfactant production that enhances lung maturity, reducing the risk of respiratory distress syndrome and other complications associated with prematurity.
While betamethasone is beneficial for fetal lung development, it does not directly prevent neonatal infections like ophthalmia neonatorum, which are caused by pathogens like Neisseria gonorrhoeae or Chlamydia trachomatis. Neonates exposed to these pathogens during birth can develop neonatal conjunctivitis or other infections. To prevent such newborn infections, other prophylactic treatments and screenings for sexually transmitted infections in pregnant women are necessary.