This is the genetics: 5 |% B: D, B- \4 B5 a g* p+ ?; Z: M D/ V6 z3 V
XY(man) x XX(woman) = ; S# t6 N6 Q7 |% U- z' u5 t/ NXX or XY, XX or XX, XY or XY. Some people have a twin. - P/ L+ Z% t0 A7 E6 a* ?6 K. Y' P3 y3 L
If 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.: `. ?9 ~1 Z0 r
4 r, k8 b- h1 z9 E( T kBecareful, eating drug may cause mutation although the possibility is not so high.