Clomid, a fertility drug that induces ovulation, is often used for annovulatory women or those with unexplained infertility, greatly increases a woman's chances of having twins. Clomid is also frequently used in combination with Intrauterine Insemination. If you want twins, Clomid may be your ticket.
IVF, which allows several embryos to be transferred into a woman's uterus at once, is another fertility treatment that increases your odds of having twins. This is perhaps the most sure-fire way of ending up with more than one baby. And finally, a woman's odds of being pregnant with twins when she conceives are better when she is older in her 40s. On the other hand, her chances of getting pregnant at all will drop significantly at a later age.
The purpose of this post is not to tell you that you can get pregnant with twins, if only you have IVF or take Clomid. Clomid is a drug that can cause serious side effects, and it should only ever be taken under the supervision of a medical professional. IVF is a very invasive fertility treatment, and the drugs that you will need to take before commencing IVF can also cause serious complications, like Ovarian Hyperstimulation Syndrome. Twins may seem nice to you, but you will likely have to give up your dreams of conceiving twins. If it will happen, great. If not, a single baby is just as wonderful.