The percentage of babies with low gestational age and the percentage of babies with low birthweight has remained broadly stable across age groups over the last 10 years.
Mae canran y babanod sydd ag oed ffetws isel a chanran y babanod sydd â phwysau geni isel wedi aros yn weddol sefydlog ar draws y grwpiau oedran dros y 10 mlynedd diwethaf.