Xenobiotic metabolism genes and the risk of recurrent spontaneous abortion

We examined the relation between spontaneous abortion and polymorphisms in two genes, glutathione S-transferase (GSTM1) and N-acetyltransferase (NAT2), which are involved in the metabolism of xenobiotics. In a case-control study of 29 women, we found that, among women with the GSTM1 null genotype, the odds ratio (OR) was 3.1 [95% confidence interval (CI) = 1.3-7.0]. There was less evidence of a relation with NAT2 [Mantel-Haenszel adjusted OR (ORMH) = 1.4; 95% CI = 0.45-4.3]. We sought to replicate the GSTM1 finding in an independent case-control study from New York involving 89 cases. We found an inverse association (OR = 0.8; 95% CI = 0.4-2.4). Taken together, these data provide little evidence of an association between GSTM1 or NAT2 genotype and risk of spontaneous abortion.