The number of births in Scotland was at the lowest since 1855 last year, although the population reached a record high, driven by migration.
National Records of Scotland (NRS) figures show 49,863 births were recorded in 2019, the lowest number since records began in the mid-19th century.
The number of deaths outnumbered births for the fifth consecutive year.
There were 58,108 deaths registered last year, a decrease of 0.7% on the number in 2018.
The NRS report said that “migration has been the main driver of Scotland’s population growth for the past 19 years”.
Pete Whitehouse, director of statistical services at NRS, said: “We’ve got a situation now where our population in Scotland is the highest it’s ever been at just under 5.5 million.
“What we see is a population that’s the highest we’ve ever had. We’ve seen year-on-year increases since the millennium, but what we’ve also seen, say in the last five years, is a situation where we’re seeing more deaths each year than we are births.
“Put these things together and what it tells us is that population growth in Scotland is being entirely being driven by migration.”
In the year to June 2019, 30,200 more people moved to Scotland than left, an increase after two years of decline in net migration following the UK’s decision to leave the EU.
However, the report noted that migration to and from Scotland, especially overseas migration, is expected to decline in 2020 due to travel restrictions which were put in place by most countries during the coronavirus pandemic.
The report also found that Scotland’s population is continuing to age and that over-65s now make up 19% of the population.
The Scotland’s Population report showed that life expectancy in Scotland has increased but improvements have “stalled” in recent years and life expectancy is lower than anywhere in western Europe.
In Scotland in 2017-2019, life expectancy at birth was 77.1 years for males and 81.1 years for females.
The council area where life expectancy at birth is highest for females is East Renfrewshire, where a girl born in 2017-2019 can expect to live for 84 years.
For males it is highest in East Dunbartonshire, where a boy born in 2017-2019 can expect to live for 80.5 years.
It is lowest in neighbouring Glasgow City Council, where females can expect to live for 78.5 years and males for 73.6 years.
When based on levels of deprivation, the gap in life expectancy between the most and least deprived areas is 13.3 years for males and 10 years for females.
The report also found that the number of marriages registered in 2019 was at an all-time low of just over 26,000.
There were 26,007 marriages in Scotland in 2019, 1,518 (6%) fewer than in 2018.
Of these, 912 were same-sex marriages involving 347 male couples and 565 female couples.
This is 67 (7%) fewer same-sex marriages than the previous year, continuing the decline since the peak in 2015.
There were 83 civil partnerships registered in Scotland in 2019, 18 more than in 2018.
The report also found that the number of households is growing faster than the population, with one in five people now living alone.
There were 472 adoptions recorded in 2019 – around half the number recorded per year in the mid-1980s, and less than a quarter of the number recorded in the late 1960s.