Neonatal outcomes in twin pregnancies in Finland from 2008 to 2023

Twin pregnancies are associated with higher risks of adverse maternal and neonatal outcomes compared to singleton pregnancies. This retrospective nationwide cohort study analyzed trends in twin pregnancy outcomes in Finland from 2008 to 2023 using data from the Finnish Medical Birth Register. Outcomes assessed included perinatal mortality, stillbirths, neonatal mortality, neonatal intensive care unit (NICU) admissions, and hospitalization rates at one week of age. A total of 23,588 twin births were included, with an overall stillbirth rate of 9.0 per 1000 and a perinatal mortality rate of 16.0 per 1000. Neonatal mortality rates declined significantly, with term twins showing a rate of 0.9 per 1000 and preterm twins 4.6 per 1000 in the latest years of 2022-2023. NICU admission rates remained stable for preterm twins but showed an increasing trend for term twins. The rate of hospitalized neonates at the age of seven days decreased over time.

These trends align with improved antenatal care and Finland's reputation for low neonatal mortality. However, increasing maternal age and obesity rates may contribute to rising NICU admissions in term twins. The study highlights the need for continuous monitoring of neonatal outcomes to ensure high standards of care in the context of declining fertility and delivery rates in Finland.

• Twin pregnancies are associated with higher risks of adverse maternal and neonatal outcomes compared to singleton pregnancies. • Finland has one of the lowest neonatal mortality rates globally.

• Neonatal mortality rates declined significantly both in term and preterm twins from 2008 to 2023. • NICU admission rates remained stable for preterm twins but showed an increasing trend for term twins.