Abstract: | Embryos from day 12 pregnant Swiss mice given intraperitoneal injections of nitrogen mustard (HN2) or cyclophosphamide (CP) were evaluated for chromosomal aberrations. Both agents induced dose-dependent increases in the frequency of cells with aberrations observed in embryos from females treated 6 hr before sacrifice. The highest frequencies of cells with aberrations were observed when females were injected 15 or 18 hr before sacrifice on day 12. A teratogenic dose of HN2 (1.0 mg/kg) induced significantly higher frequencies of damaged cells than a teratogenic dose of CP (20 mg/kg). Cytogenetic analysis of rodent embryos from pregnant females exposed to xenobiotic agents may be an effective screening test for evaluation of genetic effects induced by transplacental exposure. |