Rare literary or technical term for twins; in modern Japanese, 双子 (ふたご) is the standard word. This form may be encountered in older texts or medical contexts.
See also: 双子
In old medical books, the notation '双児' can be seen.
「双児」は「双子」と同じ意味だが、現代ではほとんど使われない。
'双児' has the same meaning as '双子', but is hardly used today.