If you are pregnant with twins, triplets or more, you have a multiple pregnancy. This means the odds that either you or one of your babies might have pregnancy related problems is increased compared to a woman carrying only one fetus. This doesn't mean you will have problems.
Many women have successful, uncomplicated twin pregnancies.
But, pregnancy involves some risk for every woman, and with each additional fetus the risks increase. The chance of having a multiple birth depends on many factors. Identical twins or triplets occur with the fertilization of a single egg that later divides into two or three identical embryos. Identical twins or triplets have the same genetic identity, are always the same sex, and look almost exactly the same. Fraternal multiples develop from separate eggs which are fertilized by different sperm.