The small-for-gestational-age twin: blessing or curse?

Area of Science:

• Obstetrics and Gynecology
• Neonatal Perinatal Medicine
• Maternal-Fetal Medicine

Background:

• Preterm delivery (PTD) is a significant concern in twin pregnancies.
• Understanding factors influencing PTD in twins is crucial for improving neonatal outcomes.
• Gestational age and fetal growth are key determinants of neonatal health.

Purpose of the Study:

• To compare the rates of preterm delivery (PTD) in twins categorized by their growth status: appropriate-for-gestational-age (AGA) and small-for-gestational-age (SGA).
• To identify factors associated with PTD at or before 34 weeks gestation in twin pregnancies.

Main Methods:

• Retrospective review of maternal and neonatal records for 679 live, nonanomalous twin pregnancies delivered at or after 25 weeks gestation.
• Twin pregnancies were classified into three groups: AGA/AGA, SGA-AGA, and SGA/SGA based on singleton growth curves.
• Logistic regression analysis was employed to assess factors influencing PTD at or before 34 weeks.

Main Results:

• The PTD rate at or before 34 weeks was significantly higher in AGA/AGA twins (38.6%) compared to SGA-AGA (14.7%) and SGA/SGA (1.4%) groups (p < 0.001).
• Twin discordance significantly increased the risk of PTD (OR = 5.05), while smallness for gestational age significantly decreased PTD risk (OR = 0.095).
• A direct relationship was observed between the relative overall weight of the twins and the PTD rate.

Conclusions:

• Appropriate-for-gestational-age (AGA) twins exhibit a higher preterm delivery rate compared to small-for-gestational-age (SGA) twins.
• The overall weight of the twins is directly correlated with the incidence of preterm delivery.
• Twin growth discordance is a significant risk factor for preterm delivery.