Mortality of twin and singleton livebirths under 30 weeks' gestation: a population-based study

Area of Science:

• Perinatal epidemiology
• Neonatal outcomes
• Multiple gestation research

Background:

• Premature birth remains a significant concern for neonatal mortality.
• Understanding differential outcomes between twins and singletons is crucial for targeted interventions.

Purpose of the Study:

• To compare mortality rates of liveborn twins versus singletons under 30 weeks gestation.
• To analyze these rates by gestational age, delivery mode, and birth year.

Main Methods:

• A population-based comparison of 479 twins and 1538 singletons born between 23-29 weeks gestation.
• Data collected from the north of England across two epochs: 1998-2001 and 2002-2005.

Main Results:

• Twins showed higher infant mortality than singletons only at 23-25 weeks gestation (OR 2.04).
• This excess was driven by early and late neonatal deaths.
• Higher mortality in twins was confined to the 1998-2001 epoch; no significant difference was observed in 2002-2005.

Conclusions:

• Excess twin mortality under 30 weeks gestation was limited to neonatal deaths in the earliest gestations (≤25 weeks) and the earlier time period.
• In the modern era (2002-2005), no increased mortality risk was found for premature twins compared to singletons.