Twin or Multiple Pregnancy
These are more frequent and are the result of two separate eggs being fertilised at the same time. This means each baby will have its own placenta, and its own amniotic sac. This means a lower risk for the babies during the pregnancy, but they will require more monitoring than a single pregnancy.

Non Identical Twins
These are more frequent and are the result of two separate eggs being fertilised at the same time. This means each baby will have its own placenta, and its own amniotic sac. This means a lower risk for the babies during the pregnancy, but they will require more monitoring than a single pregnancy.
Despite being non-identical, these twins can look very similar to each other. They can also be quite different. They can have the same gender, or you might have one of each.

Identical Twins
The result of one embryo splitting in the days after being fertilised. Because they share the same egg and sperm, and the same DNA, most identical twins look almost exactly the same. But, given the influence of environment, it is worth noting that identical twins can look slightly different.
Depending on how late the single embryo splits the two babies can share a single placenta, a single sac, or even share some of the bodies development (conjoined).
This can bring higher health risks for the baby and the mother. Guy will be able to help you understand what those risks might be, for you, and help you go into the pregnancy with the knowledge you need to be as confident as possible about the pregnancy.

Triplets, Quadruplets, Quintuplets And More
About one in a thousand pregnancies will be triplets. The chances are even rarer for higher order multiple pregnancies. And these may come from one egg cleaving several times, or multiple eggs being fertilised at the same time (as with IVF) or a mixture of both.
As with twins, there are increased risks involved with multiple pregnancies but, with appropriate monitoring and the right information, you can go into the experience with a relatively high degree of confidence.

Multiple pregnancies (twins, triplets, quadruplets and quintuplets) make up 2-3% of all births. With most multiple pregnancies being twins.
The chance of a multiple pregnancy increases with maternal age for example your chances of a multiple pregnancy at age 20years is 1% rising to nearly 10% by the age of 40 years. In addition medication that can be prescribed to induce ovulation can also increase the chance of a multiple pregnancy.