Impact of Chorionicity in Neurodevelopmental Outcomes in Preterm Twins.

Introduction Multifetal pregnancies, which account for 2-4% of births worldwide, have increased in recent years. Twin pregnancies carry a higher risk of preterm birth and associated neonatal morbimortality, with monochorionic twins considered at greater risk. This study investigates the influence of chorionicity on neurodevelopmental outcomes in preterm twins. Methods A retrospective cohort study was conducted, including preterm twins born before 32 weeks of gestational age and/or with a birth weight of less than 1500 grams, admitted to a tertiary-hospital neonatal intensive care unit from 2013 to 2021. Neurodevelopmental outcomes were evaluated at 24 months of corrected age using the Griffiths II Mental Development Scales. Moderate to severe neurodevelopmental impairment was determined by the occurrence of one or more of the listed criteria: global development quotient <70, severe visual impairment, cerebral palsy, or profound sensorineural deafness. Results A total of 125 preterm twins were evaluated, of which 45% (n=56) were monochorionic. Overall, 5.6% (n=7) of the infants had moderate to severe neurodevelopmental impairment (NDI), with higher comorbidity rates in this group. No significant differences were found in NDI or other prematurity-related comorbidities between monochorionic and dichorionic twins. Gestational age over 27 weeks and birth weight over 1010 grams were identified as accurate predictors for an absence of moderate to severe NDI in these infants. Conclusion Chorionicity alone does not appear to independently affect neurodevelopmental outcomes in preterm twins when complications are effectively managed. Improved prenatal monitoring and appropriate treatment of twin pregnancies, especially monochorionic, are crucial to mitigate risks associated with moderate to severe neurodevelopmental impairment.