Heteromorphisms are microscopically visible variant regions on chromosomes and are transmitted as Mendelian traits. Studies of heteromorphic variants allow determination of parental origin, paternity testing, maternal contamination in prenatal samples or tracing the chromosome to a parent in numerical or structural chromosomal abnormalities. Genetic counseling is important to interpret these common variants in context to patient history as they may have no consequences to mild to moderate consequences. This work presents the study and clinical correlation of common heteromorphic variations in 6166 individuals with bad obstetric history, developmental delay, fetal studies (fetal cells in amniotic fluid or product of conception) with appropriate controls. A review of published literature on the subject is also included. This work was also presented by the author as a doctoral dissertation (PhD in Life sciences) at Mumbai University India in 2012