in the medrash there is a diffrent girsa than the gemara and look up the sefer divrei yatziv from the previous Klausenburger Rebbe on this gemara(using the mafteach in the back) where he comes out that today since there is a cherem from rabbeinu gershom to marry more than one wife it is better to have girls. (the teshuva needs to be learnt slowly and understood well since it is quite complicated)I actually said this as bris torah after I made my third bris. after all is said and done its all up to the one above.