A stroller with a collapsed diameter not exceeding 25.5 cm (10 in) and a length not exceeding 92 cm (36 in) is allowed, in addition to your carry-on allowance, regardless of destination. It can be checked at the gate to be delivered to you at the aircraft door at the end of your flight.
Large strollers
Because gate facilities in airports are not designed to accommodate them, large, heavy strollers will need to be checked in and will count as one piece of baggage toward the maximum number of checked bags allowed by your fare type. Large strollers are also subject to space limitations, and there is a risk that they cannot be accommodated in the aircraft.