A new report suggests that almost one in five mothers smoke or drink at some stage during pregnancy.
The Government funded the 'Growing up in Ireland' study.
It followed the progress of more than 11,000 'nine-month-old infants' and shows that the traditional family unit remains the norm.
The report suggests that 70% of the mothers of nine-month-old infants are married. A further 15% are living with a partner.
27% of mothers and 24% of fathers were not born in Ireland.
