The article by Korsakov et al. [1] compares the prevalence at birth of polydactyly (PD), limb reduction defects (LRD), and multiple congenital malformations (MCM) in the south-west territory (SWT) of the Russian Oblast Bryansk (which is bordering on Gomel Oblast in Belarus and which was highly contaminated from the radioactive fallout of the Chernobyl accident) to the respective prevalence in two districts of Bryansk with little radioactive and chemical contamination (Kletnyansky and Mglinsky). They also conducted a pooled analysis of these three categories of congenital malformations (Total CM). They found that "the sum of all congenital malformations was 3.5-4.6 times higher in contaminated regions in comparison with the control group".To check the results I conducted Poisson regressions of the annual numbers of Total CM, i.e. for PD, LRD, and MCM combined, in the three study regions CP (for chemical pollution), RC (radioactive contamination), and CC (combined chemical and radioactive contamination). No case numbers of CM are given in Table 3, only the prevalence. Thus, the case numbers (O) needed for the Poisson regression had to be determined by the number of births (N) times the prevalence (pCM).In each of the three study regions, the prevalence pCM1 was compared with the prevalence pCM0 in the control region (ES, for ecologically safe territories). The results are shown in the table below, together with the relative risks RR ¼ pCM1/pCM0, the 95% confidence intervals of RR, and the two-sided p-values (t-tests). For comparison, the p-values from Table 4 in [1] are added.