Types of twins
How to tell if your babies are identical
Conceiving a baby is a very special gift of nature, but for a few parents the experience is made incredibly more miraculous by the news they are expecting twins (or triplets or more). For parents of multiples, the pregnancy can bring amazing feelings of joy and pride, or perhaps initial shock and disbelief until they adjust to the idea of having more than one baby! In Australia in 2003 there were 4,259 multiple pregnancies (1.7% of all births). This works out to be about 17 per 1000 births or about 1 set of multiples for every 59 births.
Essentially, multiple pregnancies progress in much the same way as singleton pregnancies and in the past (before the widespread use of ultrasound) up to 50% of twins were not discovered until the time of birth! (You can read more about this
here). However, there are some aspects of a multiple pregnancy that are different.
NOTE: We have made every effort to include relevant information for parents of multiples. However, this section and
twins, triplets or more - the pregnancy are devoted to the main differences during pregnancy. Other sections include
twins, triplets or more - the birth,
breastfeeding or
bottle feeding multiples and early parenting in
twins, triplets or more - after the birth. We realise that some multiple pregnancies involve 3 or more babies and we make reference to this wherever it is relevant. However, because most multiple pregnancies are twins, we tend to focus on them.
Types of twins
Most people are aware of the two main types of twins:
Non-identical
Identical
Non-identical twins are also known as fraternal, dizygotic or binovular twins, meaning they have developed from 2 separate eggs that have both been released by the woman's ovaries during one menstrual cycle. Each of these eggs is fertilised by 2 separate sperm from the man. (If the woman releases 3 eggs at the same time, she may conceive non-identical triplets and so on.