Nearly three in 10 births in England and Wales were to foreign-born mothers last year, the highest level on record.
Official statistics show that 28.2% of babies, or around 196,000, were delivered to mothers born outside the UK as the figure went up for the 26th consecutive year.
The proportion has increased every year since 1990, when it was just over a 10th (11.6%). It stood at 21.6% a decade earlier, and 25.5% in 2011.
In recent years, the percentage of births to women born outside the UK has been higher than the percentage of the female population of childbearing age born outside the UK.
Statisticians said this was partly due to generally higher fertility levels among foreign-born women.
Different age structures between the foreign-born and UK-born female populations of reproductive age was cited as another factor, with a higher proportion of foreign-born women being aged from 25 to 34, where fertility is highest.
The latest figures are not broken down by country, but data for 2015 showed Poland was the most common nation of birth for mothers born outside the UK, followed by Pakistan and India.
The new release from the Office for National Statistics (ONS) also revealed that nearly half of babies (47.6%) were born outside marriage or civil partnerships last year, a slight dip on 2015.
Many babies born outside marriage or civil partnership had parents who lived together, the report said.
Since 1998, over 60% of all births registered outside marriage or civil partnership each year have been to a cohabiting couple. Last year the figure was 67%.
Nicola Haines, of the ONS, said: "The percentage of births outside of marriage or civil partnership has remained relatively unchanged since 2012, following a notable increase from 5% in the mid-1950s.
"This increase coincided with cohabitation becoming more common as an alternative to marriage, particularly at younger ages."
There were 696,271 live births in England and Wales in 2016, a decrease of 0.2% from 2015.
Last year the total fertility rate fell to 1.81 children per woman, from 1.82 the year before.
The figures also showed that the average age of mothers in 2016 increased to a new peak of 30.4 years, compared with 30.3 years in 2015.
Women aged 40 and over had a higher fertility rate than women aged under 20 for the second time since 1947.
The ONS paper said: "The fertility rate for women aged 40 and over has now trebled since 1990 and is at its highest level since 1949.
"The fertility rate for women aged 35 to 39 has trebled since 1980 and is now at its highest ever level since the beginning of the time series in 1938."
Last year the stillbirth rate decreased to 4.4 per 1,000 total births, the lowest rate since 1992.