Preterm discordant twins: what birth weight difference is significant?

Area of Science:

• Perinatology
• Neonatology
• Obstetrics

Background:

• Twin gestations present unique challenges in fetal growth and neonatal outcomes.
• Birth weight discordance, a measure of unequal growth between twins, is a known risk factor.

Purpose of the Study:

• To evaluate the impact of varying degrees of fetal growth discordance on perinatal and neonatal outcomes in preterm twins.
• To identify a clinically relevant threshold for birth weight discordance in twin pregnancies.

Main Methods:

• Retrospective study of 122 twin sets delivered between 25 and 34 weeks' gestation.
• Stratification into five birth weight discordance categories (<10%, 10-15%, 15-20%, 20-30%, >30%).
• Analysis of perinatal and neonatal outcomes, including infant death, congenital anomalies, and neurological complications.

Main Results:

• Preterm twins with >30% birth weight discordance showed significantly higher rates of infant mortality (25%), congenital anomalies (37.5%), small-for-gestational-age infants (31.8%), low Apgar scores (33.3%), and periventricular leukomalacia (16.7%).
• All recorded deaths in the >30% discordance group occurred in the smaller twin.
• Higher cesarean delivery rates (79.2%) were observed in the most discordant group.

Conclusions:

• A birth weight difference exceeding 30% in preterm twin gestations is a critical indicator for identifying infants at high risk for adverse perinatal outcomes.
• This threshold aids in clinical management and targeted interventions for high-risk twin pregnancies.