A 4-year-old boy presents with multiple fractures of the femur and humerus sustained from minor falls. Clinical examination reveals blue sclerae, translucent gray-brown teeth, and conductive hearing loss. Genetic testing of the parents' blood DNA is completely normal. The pedigree shows two unaffected parents with two affected children (both with identical COL1A1 mutations). The mechanism marked **A** in the pedigree diagram — germline (gonadal) mosaicism — explains this inheritance pattern. Which of the following statements best describes the genetic counseling implication for this family regarding future pregnancies?