Finland's increase in births, recorded in the months following the first two waves of the COVID-19 pandemic, was among the strongest. We assess whether the fertility increase in Finland occurred because of or despite the pandemic, or both, by investigating the country’s fertility trends by women’s region of residence, age group, and parity. While the country as a whole was modestly hit by the pandemic in 2020, the capital region Helsinki-Uusimaa faced more severe restrictions. We used aggregate register data until September 2021 to assess monthly fertility. In 2020 and 2021, the relative annual increases in fertility were strongest among women aged 30–34 and 35–49. In 2021, but not in 2020, fertility increased most in Helsinki-Uusimaa, and across all parities. Model-based estimates provided tentative support for an overall pandemic fertility boost for the time period until September 2019. We conclude that the unusual fertility increases in 2021 in Finland broadly follow from pre-existing trends where the country recovers from its all-time low fertility, but do not exclude the possibility of an additional boost from the pandemic itself. The study highlights the importance of carefully considering existing fertility trends when studying fertility responses to the pandemic.