A clinicallly detectable pregnancy that fails disorders of preg preg- pregnancy of 24 all weeks past to in progress 10-20% detectable a clinically and occurs gestation, Selenium Miscarriage Miscarriage, nancy that nancies 69 Genetic (chromosomal) ab normalities explain at least half of all miscarriages. Although anatomical, en- docrine, immune, infective, and throm bophilic conditions are other possible causes, most chromosomally normal miscarriages remain unexplained or idiopathic.