That's suppose to say Viagra not Vista*****
http://www.malefertility.md/infertility-faqs.html According to this website Viagra does not effect sperm count. If it is a performance issue due to stress Viagra can help you with that.
Yes he already had a girl! To start you always want to check with a doctor but I don't think Vista would have any effect on your fertility. I think as far as that goes it is a safe med. However it can lower your blood pressure so make sure before you take it you don't have a low blood pressure.
She already had the girl? Or is she still pregnant? If she is still pregnant you have to wait until a little after she gives birth to try again. I don't know about viagra and sperm viability. You should post this question in the forums where doctors answer your questions. They're the ones who know for sure.
We already having a girl and now we are trying for boy but problem is erection so can I take vigra
I would call a doc. I'm not familiar with that & if ur already expecting a girl u can't get pregnant again unless ur trying with another woman nor is there a guarantee for a boy.