Chromosomes and oral contraceptives: aberrations in relation to neoplasia.

It is now possible to test the effectiveness of suspected mutagens in producing chromosome breaks and their sequelae in mammalian cells by cytological observations on cultured cells. Chromosome preparations were processed from peripheral blood leukocytes of 185 mothers who had used hormonal contraceptives and from their newborn children; 181 controls were also studied. In the test mothers group 114 cultures produced analyzable metaphase spreads and 153 from their babies were satisfactory. Of the controls 126 mothers and 157 babies gave readable results. In the control group there were 81 male babies vs. 96 in the test group. Altogether 11516 metaphase cells were analyzed. 295 cells were found with an abnormal chromosom count or a structural alteration excluding those cells with 44 or 45 chromosomes. The structural aberrations of the chromosomes were mainly gaps and breaks. There were 6 triploid cells (69 chromosomes) in the test babies group but only 1 in the control group. Altogether 71 structural abnormalities were seen in the chromosomes 22 in the control mothers group 20 in the test mothers 11 in control babies and 18 in test babies. The largest difference in chromosome abnormalities was in the babies groups with nearly 5 times as many gaps in babies whose mothers had been taking oral contraceptives (p = .01). In the mothers the percentage gaps were not significant. The possible effects of X-ray exposure and of other drugs was also considered. Of test mothers 8.4% worked in hazardous occupations and 19.3% of their slides had chromosome abnormalities. In the control group 2 mothers and 8 fathers worked with agricultural chemicals. In the test group 6 mothers and 8 fathers worked with these substances. A background of genetic damage exists in the external environment. A chemical or drug under study should be evaluated with this in mind. It is concluded that a possible relationship of the combined effects of oral contraceptives and external hazard was not shown in these studies although minor differences were found in the babies.