Secret Pregnancies/Children

ML doesn't know, FL has amnesia

due to amnesia

in the bonus epilogue, while the ML is gone

gender-flipped, FL believes the baby died, ML raises him

briefly

FL believes the ML is dead

while the ML is missing/presumed dead

while the ML is gone

in season 2

briefly

due to the FL's amnesia

neither lead knows due to time travel

gender-flipped. FL thinks the baby is dead, but the ML hid and raised him.

due to amnesia

in season 2, due to the leads being separated across time

while the ML is missing during the war

very briefly, while FL is missing

while the ML is gone

gender-flipped, FL believes the twins died, ML raised them

very briefly while the ML is missing/presumed dead

gender-inverted, FL believes the baby died and ML raises him