This is the genetics: 8 W6 V7 C( }% V( } , P H+ s/ q# BXY(man) x XX(woman) = 2 a7 c: s3 G- o! s, J
XX or XY, XX or XX, XY or XY. Some people have a twin. : B) N3 q( }0 Y. f! e
3 k) g+ S6 [! w- E' n2 r- UIf you really need a boy, you can ask a doctor to take your Y only and injiect into your wife's XX, then you will have boy only.& D$ `5 n K/ L. U0 r
7 C" M! G j7 c$ X- D3 J6 W1 ]
Becareful, eating drug may cause mutation although the possibility is not so high.