My 7 month old baby has larangalmacia when he was born it seem to get better when he was 3 months now it has returned with loude breathing during slep?

Several reasons: As you have seen, laryngomalacia usually improves with age, but worsening may mean one of several things. The most common one may be a cold or viral infection. The breathing noise wuld go away if this is the case, once he recoveres. Did he lose weight recently? In that case the tissue around the airtube may have gotten loose. Did he develop asthma? Does he suffer from second hand smoking?

Laryngomalacia: Be patient. 90% of cases will resolve in time by 18 months to two years old . Noisy breathing steadily increases over the first six months as inspiratory inflow increases with age .It gets worst before it improves, usually 4-8 months.