van Zijl MD, Koullali B, Oudijk MA, et al. - As perinatal morbidity and mortality in most cases are significantly due to preterm birth, researchers here attempted to provide an overview of the trends in preterm births for both singleton and multiple gestations in the Netherlands in order to guide future research. They studied a nationwide cohort including 1,303.786 women with a singleton and 44,951 women with a multiple pregnancy between 2008 and 2015. Observations revealed a decrease in preterm birth risk in singletons in the Netherlands between 2008 and 2015 but there was an increase in preterm birth ≤ 27 weeks. In multiples, an increase in the total preterm birth risk was observed, due to an increase in indicated preterm birth. In singletons, there was a decrease in preterm birth < 37 weeks from 5.6 % in 2008 to 5.3 % in 2015, in both spontaneous and iatrogenic preterm birth. An increase in preterm birth ≤ 27 weeks was observed from 0.40 % to 0.45 %. They identified a decrease in the number of multiple gestations over the years, as well as the percentage of multiples conceived through IVF/ICSI. Total and iatrogenic preterm birth < 37 weeks increased from 36.7%–38.2% in multiples. Both the spontaneous and iatrogenic groups showed a decrease in the number of multiples < 32.