Mortality in multiple vs. singleton very low birth weight infants in Germany A population-based study

Area of Science:

• Neonatalogy
• Perinatology
• Public Health

Background:

• Conflicting international data exist on mortality rates for multiple births versus singleton births.
• Previous studies suggest multiple births are associated with increased mortality, but European data are inconsistent.
• Gestational age is a critical factor in preterm infant survival.

Purpose of the Study:

• To investigate the association between birth plurality and survival rates in very low birth weight infants.
• To analyze survival differences between singletons and multiples in relation to gestational age.
• To provide evidence for optimizing care for preterm infants.

Main Methods:

• Analysis of a large German population-based cohort of preterm infants (<1500g birth weight) from 2010-2017 and 2019-2024.
• Mandatory quality improvement data from all German hospitals were used.
• Comparison of mortality rates between singleton and multiple births, stratified by gestational age.

Main Results:

• Multiples constituted a significant proportion (28.2% twins, 3.9% triplets) of infants <1500g birth weight.
• Overall mortality was lower for twins (7.3%) and triplets (6.2%) compared to singletons (9.0%).
• However, infants born before 25 weeks gestation had higher mortality if they were multiples (40.5%) versus singletons (37.6%). Survival improved for multiples in later gestational age groups (25-27, 28-30, >30 weeks).

Conclusions:

• In very low birth weight infants, multiple births are associated with higher survival rates than singletons.
• This survival advantage for multiples is not observed in extremely preterm infants born before 25 weeks gestation.
• Gestational age is a crucial determinant of survival differences between singleton and multiple births in the neonatal period.