It showed that a previous attempt to forecast immigration figures underestimated the number of females coming to live in the country by 361,000 and overestimated the number of males by 94,000, when compared with census data.
Female migration has been concentrated in the 20 to 44-year-old age bracket, the prime years for child bearing, and may have contributed to a mini baby boom, according the analysis by the Financial Times.
The official data from 2001-2010, released in July, showed net migration to England and Wales increased the population by more than 2.1 million.
Figures also show that more than a quarter of all births are to non-UK born women, boosting the number of children aged 0-8 years by nearly 300,000 since the last census in 2001.
Pakistani women have been overtaken by those from Poland as the single largest group of foreign-born mothers in 2010 and 2011, making up more than one in 10 births within this group.
The analysis comes with immigration continuing to be a part of the political agenda, after David Cameron announced a review into the freedom of EU citizens to live and work in the UK - despite any limitation on this being barred under EU agreements - amid job fears for young Britons.
Economists and population analysts point out the positive impact, because UK fertility rates are too low to maintain the population at the same level, which is likely to see the burden of paying for the nation's elderly falling on fewer shoulders.
Data released by the ONS in August showed women born in the UK were having an average of 1.9 children each, below the rate of 2.1 that is thought necessary to keep a population level. But when non-UK born women are included, the rate goes up to around 2.0.
Gordon Sharp, head of the Continuous Mortality Investigations unit, an actuarial body, said it meant that the cost of supporting the nation's elderly in 30 years would be spread among more workers.
He said: "It means the dependency ratio is not as severe as it might otherwise be."
But he noted that the rise in births would result in some higher costs in the short term including healthcare and education.