Assessment of fetal growth in twins: Which method to use?

Area of Science:

• Maternal-fetal medicine
• Perinatology
• Obstetrics

Background:

• Fetal growth restriction (FGR) significantly increases perinatal mortality and morbidity in twin pregnancies.
• Twin fetuses exhibit divergent growth patterns and are typically smaller than singletons, especially after 28-30 weeks' gestation.
• Current clinical practice often relies on singleton growth standards for twin pregnancies, despite established differences.

Purpose of the Study:

• To review evidence supporting the use of twin-specific fetal growth standards.
• To discuss the rationale, clinical evidence, and future research directions for implementing these specialized standards.
• To highlight the limitations of applying singleton growth charts to twin gestations.

Main Methods:

• Review of existing literature on factors influencing fetal growth in twins.
• Analysis of studies comparing singleton and twin-specific growth standards.
• Examination of the association between growth classifications and perinatal/maternal outcomes.

Main Results:

• Singleton growth standards overestimate the rate of abnormal growth in twins, leading to overly stringent classifications.
• Twin-specific standards demonstrate a stronger association with adverse perinatal outcomes, including perinatal death, preterm birth, and neonatal unit admission.
• Evidence supports the clinical utility of twin-specific charts for more accurate risk assessment.

Conclusions:

• Twin-specific growth standards are crucial for accurate diagnosis and management of fetal growth restriction in twin pregnancies.
• Clinical implementation of twin-specific standards is necessary to improve antenatal care and reduce adverse outcomes.
• Further research is needed to refine and integrate these standards into routine clinical practice.