New figures for Oxford reveal that close to half of all births were to non-UK mothers.
Population statistics for 2010 show that 47 per cent of babies were to mothers born outside the UK, compared to the national average of 26 per cent.
Oxford City Council‘s report shows the city’s annual birth rate has risen by 40 per cent in less than a decade.
Figures also show the number of babies born to UK-born mothers living in Oxford has remained almost unchanged over the last 10 years.
The report by Mark Fransham, the city council’s social research officer, is based on data from the Office of National Statistics.
Mr Fransham said: “The UK birth rate has been rising since 2002, the result of an increase in the number of women of child bearing age, driven by international immigration and a rise in births per woman.”
In 2006, births in Oxford to mothers born outside the UK was 34 per cent. The 2010 figure was 47 per cent. Countywide a quarter of all births were to non-UK mums.
A breakdown shows the highest group of non-UK born mothers in the city were from Asia, making up 17 per cent of the Oxford births.
Babies born to Asian mums rose from 170 in 2001 to 354 in 2010, while the total from the EU more than doubled to 13 per cent.
African born mothers made up eight per cent and the rest of Europe three per cent.
Babies born to UK-born Oxford residents remained stable changing from 1,045 out of a total of 1,505 in 2001 to 1,103 out of 2,100 in 2010. The figures are based on mothers with Oxford addresses.
Mr Fransham said: “Oxford has always been a diverse, international city attracting people from all over the world.”
County Hall said it was already focusing on creating additional school places in the city.
Paul Smith, spokesman for Oxfordshire County Council, said: “It is true that there are a large number of pupils who do not speak English as a first language within Oxford.
“While it is true to say that this will always have an impact on educational attainment, it cannot be used as an excuse.”
At the 2001 Census, Oxford’s resident population was estimated to be 134,248. By 2010 it had risen to about 153,700.
Jolanta Oamen decided to take a break from her university studies in Poland to learn English in Oxford.
She married, has a three-year-old son Oliver, a home in Greater Leys and is now running her own child minding business.
The 30-year-old, of Elder Way, said: “When I first arrived I hardly saw anybody from Poland. Now you see Polish people all the time. I can recognise them before even hearing them speak.
“Most Polish people who come here, I think, want careers. They want to stay a few years and then go back.”