The definition of the "crude birth rate (CBR) is the number of births per 1,000 population during a specified time period".[6] The 2004 Bangladesh DHS reported a current CBR for urban Bangladesh of 25.8 per 1000 population for 3 years prior to survey. Thus the average expected number of births for each Mahallas over a 3 month period would be 150, which would be more than the required recruitment number for the trial and ensuring the feasibility of the sampling scheme for the trial.