Twins account for around 90% of multiple births and far outnumber triplets or quads in the multiple birth stakes. Currently in Australia almost 2% of all babies born come in multiples.

Double trouble! Once you have found out that you are expecting twins it can very exciting. It can also be scary as you think about how you will juggle two babies at once.

The following information aims to help you to understand more about twins and offers some ideas about how to care for them. Most of the information also applies to triplets and other multiple births.

How will I know if I’m having twins?

You may suspect you are having twins long before they are positively diagnosed. The pregnancy hormone, hCG is being produced in massive quantities and its effects on your body become very evident. One of the first symptoms is likely to be extreme nausea and the inability to keep any food down. You’re likely to be able to tick all the boxes for early pregnancy symptoms, but increase them tenfold - smells are more acute, your bladder seems miniscule, you’re absolutely exhausted and your breasts have taken over your chest.

Pregnancy is usually not obvious until after the 12th week when the uterus starts lifting up out of the pelvis. Two babies, however, take up double the space so it’s likely you’ll “show” much sooner and often a little round bulge is visible long before the end of the first trimester.

Another give away sign is lots of movements, felt earlier than normal. Quickening is not generally felt until around 16 weeks by first time mothers and as early as 14 weeks for those who’ve been pregnant before. But with twins, those tiny first movements can be very clear as they fill up the uterus much earlier than one baby and are in contact with the uterine wall as they bounce and flit around.

You may also find out from having an ultrasound and see two babies on the screen. Sometimes pregnant mothers don’t know they’re having twins until the 18 week screening ultrasound; others as early as 12 weeks. It’s possible to see on ultrasound at 12 weeks or earlier which type of twins a woman is carrying.

Finally, a twin pregnancy can be detected through Doppler; when two separate heartbeats are heard.

How are twins formed?

Identical twins (or monozygotic twins)

• Identical twins occur when a single sperm fertilises an egg, and then, at a very early stage, the fertilised egg divides into two and starts forming two babies.
• Identical twins have the same genes, so they are the same sex.
• Some of these twins have their own separate placenta (afterbirth) and sac to grow in the mother’s uterus (womb) but many share the same placenta and sac.
• Monozygotic twins may be quite different sizes at birth, but they become more alike with time. They are often hard to tell apart when they are older.
• Identical twins do not usually “run in families” and it is not known why monozygotic twins occur.
• Identical twins happen about once in every 250 live births.

Non-identical twins (or dizygotic twins)

• Non-identical twins are also sometimes called fraternal twins. They happen when two separate eggs are fertilised by two different sperm so that two embryos (the beginnings of a baby) are formed.
• Each has its own separate place in the uterus and separate placenta and sac.
• They may be the same sex or different sexes.
• Dizygotic twins are often similar at birth, but they become less alike as they get older, as do other (different age) brothers and sisters.
• Dizygotic twins are more likely to happen when there are twins in the mother’s family, or if the mother has been having fertility treatment. If a mother is a non-identical twin, she has about a 10% chance of having twins herself. (A mother of twins who is not a twin herself, has about a 5% chance of having another set of twins). If the father is a twin, this does not make it more likely that the parents will have twins.
• About two births in every hundred are dizygotic twins. There has been a rise in the number since the use of fertility treatment has become more common.

Siamese twins (or conjoined twins)

• Siamese twins are extremely rare.
• Conjoined twins come from the same egg (monozygotic) but the embryo does not separate completely to form two separate babies. This means that the babies are joined together in some way. Some can be separated by an operation without too much difficulty. In other cases they share vital organs and cannot be separated without the death of one or both twins.

What are the risks of having twins?

There is a greater risk of miscarriage and other pregnancy complications. The “safest” twin pregnancy to have is considered to be the fraternal twin variety. This is because each twin will have its own placenta and amniotic sac.

Common twin pregnancy complications for the mother include:

• Morning sickness which commonly extends to hyperemesis Gravidarum (extreme vomiting).
• Gestational Diabetes.
• Pre-Eclampsia.
• Premature birth. If a mother can get to 38 weeks carrying a twin pregnancy she is doing very well.
• Caesarean section delivery – particularly if this is the mother’s first pregnancy and she has not laboured before.
• Bleeding/placenta praevia/placental abruption.

Common twin complications for the baby include:

• Smaller birth weight.
• Jaundice.
• Problems with feeding.
• Longer stay in hospital after birth.
• Occasionally the babies have problems maintain their body temperature and stabilising their blood sugar levels.
• Infections and vulnerability due to their size.
• Breathing problems.

Preparing for twins

It is important to prepare your mind as well as your body for the twins’ arrival.

• Once you know you are having twins it is a good idea to start thinking about them as separate individuals so you can get to know them.
• You can start building your relationship with your babies by getting to know their movements and their position in the womb. You can also use ultrasound pictures to share your experiences with the babies' father.
• You might feel emotionally and physically drained by the changes happening to your body. It is important to share these feelings with your loved ones. This helps them to start sharing the care.
• You are doing the best thing you can by reading as much as you can about twins and how to care for them.
• If you get offers of help – accept! You may feel uncomfortable about this at first. Every bit of help you get will help you to build a better relationship with your babies. People like to be helpful. You could, for example, accept help with cleaning, ironing, shopping or with preparing food.
• · Freeze some meals in advance for times when you need them after the birth.
• · In the first few weeks while you are getting settled you may need a lot of help. This is a good time to plan for your partner, a family member or family friend to be available to help out.
• · Plan what you are going to do about nappies. A nappy service or disposable nappies may be helpful.
• Because twins often come early, plan to go to your antenatal classes a bit earlier than usual to make sure you can complete them. Your midwife or doctor will be able to help you with this planning.
• If you have other children at home, particularly very young children, think about how you are going to prepare them for the new babies.

Feeding twins

Because breast milk supply increases with extra demands, most women can breastfeed twins well. This can mean much less work compared to preparing and giving formula. However, because of the extra challenges of feeding two babies, you may wish to get some support from your nurse or midwife, local breastfeeding association or a lactation consultant.

You can feed your babies together or separately. Feeding both babies at once can give you more time to get some rest in between feeds, however you may want to feed separately some of the time so you get more chance to get to know each baby.

If you are bottle feeding your babies, it is often recommended to feed each baby separately, as this separate closeness and touching helps encourage bonding with the baby. If you try to feed them together you will find you are holding the bottles, not the babies!

Caring for twins at home

Looking after even one baby can make you feel very tired, and caring for two babies can be even harder if they are unsettled. The most common cause of depression for new mothers is fatigue. If you are experiencing stress, anxiety or depression seek help immediately.

It’s important to remember that despite all the challenges, the excitement and joy of having a multiple birth makes up for the hard work.