The total dose of rFSH at the end of the follicular phase was significantly reduced in the CD4 group compared with the CD2 group ( 324 ( 276 ) IU in the CD2 group versus 173 ( 255 ) IU in the CD4 group , P = 0.015 , mean difference -151 , 95 % confidence interval ( CI ) -301 to -1 ) .