Herbs that Increase Egg Production

I saw a t.v. program on Discovery Health channel about a woman who naturally conceived quadruplets. The mother to be hadn't been trying to conceive but had been taking natural herbs purchased at a health food store. According to her OB/GYN, these herbs increased her egg production. What herbs could she possibly have taken that increased her egg production THAT much?

I'm sorry, but I have no idea what herbs, if any could have this effect.