Discordant twins: diagnosis, evaluation and management

Area of Science:

• Perinatology
• Maternal-Fetal Medicine
• Obstetrics

Background:

• Twin gestations represent a significant portion of multiple births.
• Discordant growth, defined as a difference of at least 20% in fetal weight, affects approximately 16% of twin pregnancies.
• This divergence in growth is associated with increased risks of morbidity and mortality.

Purpose of the Study:

• To identify risk factors associated with divergent fetal growth in twin gestations.
• To outline diagnostic and risk stratification strategies for twin growth discordance.
• To provide insights into the optimal management and timing of delivery for affected pregnancies.

Main Methods:

• Systematic review and categorization of identified risk factors (maternal, fetal, placental).
• Analysis of diagnostic accuracy using likelihood ratios from first and second-trimester examinations.
• Review of current literature on antepartum testing and delivery considerations.

Main Results:

• Fourteen risk factors for divergent growth were identified, categorized into maternal, fetal, and placental origins.
• Early ultrasound examinations (first and second trimesters) showed moderate likelihood ratios for detecting discordance.
• Discordant growth itself is not a sufficient indication for preterm delivery.

Conclusions:

• Early identification of twin growth discordance requires careful assessment of chorionicity and serial ultrasounds.
• While diagnostic capabilities are limited, suspected cases at viable gestational ages warrant antepartum surveillance.
• Optimal management strategies and timely delivery protocols for discordant twins require further research and standardization.