The rate for 6-month-old children whose mothers were 35 or older was 30 percentage points higher than those whose mothers were aged 19 or younger.
Roedd y gyfradd ar gyfer plant 6 mis oed yr oedd eu mamau’n 35 oed neu'n hŷn 30 pwynt canran yn uwch na'r rhai yr oedd eu mamau yn 19 oed neu'n iau.