Denmark’s response to the COVID-19 pandemic was to issue guidelines on containment, isolation, and surveillance. Subsequently, Denmark entered a period with variable mitigation measures including closures of schools and workplaces, travel restrictions, and restrictions on public gatherings. A Danish study covering the lockdown period (March 12 – April 14, 2020) as well as a period of mitigation measures (February 27 – September 30, 2020) showed that the reduction in extremely preterm births was not associated with an increase in singleton stillbirth rate. Subsequent studies examining the impacts of COVID-19 mitigation measures on preterm birth have combined singleton with multifetal pregnancies. However, multifetal pregnancies have a different set of risk factors for preterm birth, as well as, increased risk of adverse outcomes, and a shorter expected pregnancy length. We assessed the impact of the Danish lockdown period, or the mitigation period on multifetal births and found no significant difference in the proportion of preterm twin births among all twin births, either within gestational age groups or in total, for either period.