The proportion fell to three in ten (31%) of pregnant women aged 25 to 29, and to a little over a quarter (27%) for women aged between 30 to 44.
Roedd y gyfran yn gostwng i dair o bob deg (31%) o fenywod beichiog rhwng 25 a 29 oed, ac i ychydig dros chwarter (27%) ar gyfer menywod rhwng 30-44 oed.