How common is a twin pregnancy?
The chance of having identical twinshas remained fairly constant throughout the world. One out of 250 women will have identical twins. However, the rate of having non-identical twins or fraternal twins, is increasing all the time. The advent of IVF (in vitro fertilisation or ‘test tube baby’) has also contributed to the increase.This procedure typically involves implanting more than one embryo in the uterus and, therefore, is more likely to result in twins, triplets, quadruplets or more. There are two different kinds of twins: * Identical twins are rarer and are derived from a single fertilised egg. Identical twins may share a placenta, but each baby usually has its own amniotic sac. The twins will have identical genes and be of the same sex, have the same blood type, hair colour and eye colour, and are difficult to differentiate in appearance. * Non-identical twins or fraternal twins are derived from two fertilised eggs released during the same menstrual cycle. These twins will have g
