<prompt> Which among the following is the most common chromosomal anomaly encountered in spontaneously aboed foetuses?Trisomy 13Trisomy 18Trisomy 21Trisomy 16  <response>: Among the spontaneously aboed foetuses, autosomal trisomies are the most common chromosomal caus. Within this category, trisomy 16 is the most frequent The recurrence risk of trisomy 16 is negligible in subsequent pregnancies 