No, if both tubes are blocked, pregnancy will be possible with IVF (In Vitro Fertilization) only. But, if just one tube is blocked (unilateral obstruction), a natural pregnancy is still possible as long as the woman has normal ovulation cycles, although the chances are reduced by 50%. Another option would be Intrauterine Insemination (IUI), monitoring the cycle in order to make sure the woman ovulates on the unblocked side.