Exploring the Association between Prenatal Growth and Differences in Sexual Development in Newborns

Area of Science:

• Pediatric Endocrinology
• Genetics
• Reproductive Medicine

Background:

• Differences in sexual development (DSD) are associated with a higher prevalence of being born small for gestational age (SGA).
• Understanding the relationship between SGA and DSD is crucial for comprehensive patient care.

Purpose of the Study:

• To determine the prevalence of SGA in a cohort of DSD patients.
• To investigate the association of SGA with sex chromosome constitution, molecular diagnosis, and clinical phenotype in DSD patients.

Main Methods:

• Retrospective analysis of 642 DSD patients' perinatal data (gestational age, birth weight, birth length).
• Classification of DSD patients based on karyotype (chromosomal, 46,XX, 46,XY).
• Subgroup analysis of 46,XY DSD patients based on molecular diagnosis and gonadal dysgenesis.

Main Results:

• Overall SGA prevalence was 30.2% in chromosomal DSD, 7% in 46,XX DSD, and 27.5% in 46,XY DSD.
• In the 46,XY DSD group, SGA was more frequent in patients without a molecular diagnosis and without gonadal dysgenesis.
• A molecular diagnosis was identified in 35% of 46,XY DSD patients.

Conclusions:

• High SGA prevalence in sex chromosome DSD and 46,XY DSD reinforces the SGA-DSD association, especially in 46,XY DSD without clear molecular diagnosis or undervirilization disorders.
• Lower SGA prevalence in 46,XX DSD aligns with expectations for the Latin American population.
• Early embryonic growth, development, and gonadal differentiation factors may link SGA and DSD; further etiological studies are needed.