If bih rate of a sub-centre of population 5000 is 25/1000 then expected no. of pregnancies in a year will be:

Expected no. of live bihs (Y)/year = Bih rate (per 1000 population) x population of the area /1000 As some pregnancies may not result in a live bih (i.e. aboions and stillbihs may occur), the expected number of live bihs would be an under-estimation of the total number of pregnancies. Hence, a correction factor of 10% is required, i.e. add 10% to the figure obtained above. So, the total number of expected pregnancies (Z) = Y + 10% of Y Given Bih rate is 25/1000 population Population under the sub-center 5000 Therefore, expected number of live bihs= {25 x 5000}/1000= 125 bihs Correction factor (pregnancy wastage) = 10% of 125 say 13 Therefore, total no. of expected 125 + 13 =138 pregnancies in a year