I think the fertility treatment for male and female sims doesn't work all the time. I tried it with a couple, and used the try for baby option. The treatment did not end in pregnancy. The funny thing is after not using the try for baby option for a long time, I had the couple try again. Luckily, they were pregnant and got twins. Then the next time they tried they again got twins. The fertility treatment is a waste of money, but can be used to add realism to the game. In real life couples have a hard time to get pregnant. So, I figured it was a rough patch for this couple and brought it into my gameplay.