It is confirmed that Qiao Yang can get pregnant, as long as his espers are highly compatible, which the twins are. In chapter 76 the doctor asks if they used condoms or contraceptives and did a pregnancy test (through blood sample). The doctor also states pregnancy is actually highly possible between them.
Update:
It is confirmed that Qiao Yang can get pregnant, as long as his espers are highly compatible, which the twins are. In chapter 76 the doctor asks if they used condoms or contraceptives and did a pregnancy test (through blood sample). The doctor also states pregnancy is actually highly possible between them.