Which finding indicates a genetic risk factor? The nurse in charge is reviewing a patients prenatal history.  

The patient has a child with cystic fibrosis

Cystic fibrosis is a recessive trait; each offspring has a one in four chance of having the trait or the disorder. Maternal age is not a risk factor until age 35, when the incidence of chromosomal defects increases. Maternal exposure to rubella during the first trimester may cause congenital defects. Although a history or preterm labor may place the patient at risk for preterm labor, it does not correlate with genetic defects.