What are multiple births?
Multiple births are often when more than one fetus is carried to full term during pregnancy. Identical births are caused when the fertilized egg splits into two or more embryos. Identical twins are the most common result when an egg splits, however identical triplets occur once in every 500 000 births. How do they happen? Multiple births are most commonly associated with IVF pregnancies and women who are taking fertility drugs, however they also occur naturally. Twins occur in one in 80 pregnancies and triplets in one in every 6400 pregnancies. The older a woman is, the more likely she is to have a multiple birth. Since the invention of fertility drugs and IVF multiple births have become more common, with 35% of pregnancies that arise from these treatments being multiple births. Stats in Australia • In 2003 there were 4,259 multiple births in Australian, or roughly 1.7% of births. • Of these multiple births 4,179 were twins, 76 were triplets and 4 were quadruplets. • 17 per 1000 births
