Effect of passive tobacco smoking on fertility of female mice.

OBJECTIVE To determine the adverse effects of passive tobacco smoking on fertility of female mice and the preventive role of antioxidants, if any. STUDY DESIGN Randomized controlled trial. PLACE AND DURATION OF STUDY Anatomy Department, CPSP Regional Centre, Islamabad, from February to July 2005. METHODOLOGY One hundred and seventeen female mice (Balb C) were selected by random sampling. They were mated and grouped as C (n=30) control, S (n=40) exposed to passive smoke in a whole body exposure chamber and SV (n=37) exposed to smoke and given antioxidants (vitamin C, E). At 19 days postcoital they were sacrificed and the number of pregnant animals, fetuses and resorption cases were counted. Histological study of uteri without fetuses was done in H and E stained sections for confirmation of pregnancy. Percentages were calculated and Chi-square test was used to calculate statistical significance. RESULTS The percentage of pregnancies was 55.00% in S and 80.00% in C (p=0.029). The percentage of animals with more than 11 fetuses was 5.0% in S and 33.30% in C (p=0.001). The percentage of animals with resorption was 31.80% in S and 0.00% in C (p=0.005). These values in SV were 64.86%, 18.90% and 20.80%, which were not significantly different from S (p=0.378, 0.216, 0.390 respectively). Histological study of resorption sites revealed decidual reaction / remnants of the placenta. CONCLUSION Passive tobacco smoke has adverse effects on fertility of female mice, which were not prevented by antioxidants. Either those were due to other chemicals present in smoke, or the antioxidants were inadequate to neutralize the free radicals.