Just under 20% of babies born last year in Doncaster have mothers born outside the UK, according to the Office of National Statistics (ONS).
Figures show that last year, 619 of the 3,444 births in the area were born to non-UK-born mothers, a rate of 18%.
This is lower than the England and Wales average of 28.4%.
Of the estimated 619 mothers born outside the UK who gave birth last year in Doncaster, the most common place of origin was the EU - making up 65.1% of the group.
Some 5% of the non-UK born mothers were originally born in European countries outside the EU, 21% in the Middle East and Asia, and 7.3% in Africa.
The ONS report said that the figures for non-UK born mothers includes those who moved to the UK as children and have lived there most of their lives, as well as those who have recently migrated.
It also said that the figures for UK-born mothers include the children of second or third generation immigrants.
Analysis of the Annual Population Survey by the Migration Observatory at the University of Oxford found that there is a higher proportion of migrants among people of childbearing age.
In 2017, 28% of 30 to 39-year-olds were not born in the UK - compared with 14% of the population overall.
Migration Observatory director Madeleine Sumpton said that this partly explains why the national numbers are high.
She said: "People migrate at all ages, but in general it's harder for families to migrate.
"People in their 20s and early 30s generally have fewer attachments, and it's more worthwhile for them to move."
The Migration Observatory also reported that 62% of foreign-born residents have been in the country for more than 10 years, and that a third arrived in the UK when they were under 18.
Ms Sumpton said: "Migrants who arrived in the country as children are relatively settled, and in many cases they will be socioeconomically indistinguishable from the UK-born."
The highest percentage of births to non-UK born mothers in England and Wales was in Brent, where 75.7% of mothers were born outside the UK.
The lowest percentage was in Redcar and Cleveland and South Staffordshire, where 3.7% of mothers were born outside the UK.
ONS senior statistician Liz McLaren said: "There are large variations in the percentage of births to women born outside the UK across England and Wales.
"This is due to local area differences in the percentage of women born outside the UK, and due to differences in fertility levels of migrants born in different countries."
In the five years from 2012 to 2017, the total number of births in Doncaster fell - from 3,752 births in 2012 to 3,444 last year.
During the same period, the number of births born to non-UK-born mothers increased significantly - from 497 births in 2012 to 619 last year.