Your Stata code should work. The discrepancy in the number of cases is small and may be due to the difference between de facto and de jure residence (see hv102 and hv103 in the household file, v134 in the IR file). Or it could be the difference between the women who are in the PR file and those who are in the IR file. These numbers may differ slightly. Please look into those possibilities. If you still can't get a match, please tell us.