The number of twin pregnancies has steadily increased over the last decade. In Europe approximately 1 in 80 pregnancies are twins and multiple births are more common nowadays. This is partly due to the increase in fertility treatment and also because women are delaying getting pregnant, thus increasing their chances of multiple pregnancy. Whatever the reason, having twins is something special.
Twin and multiple pregnancies are considered high-risk for both mother and baby. For the mother, there is an increased risk of complications, for example, gestational diabetes (see page 81), pre-eclampsia (see page 110) and anaemia. For the babies, the risk of growth restriction and pre-term labour are of particular concern. Therefore, you will be offered close antenatal care and regular scans to monitor the growth of your babies.
The first few months
In early pregnancy, an increase in common symptoms, such as pregnancy sickness or excessive tiredness, or simply an unusually large uterus, may suggest that you are carrying twins. However, the obstetrician needs to know not just how many babies there are but also the number of placentas.
In the majority of twin pregnancies, there are separate placentas (dichorionic twins). In about 20 per cent of these pregnancies, the placenta is shared (monochorionic twins). Monochorionic twins have much higher complication rates and therefore need closer monitoring.
As with one baby, twins can be screened for Down's syndrome at 11-14 weeks by looking at the nuchal translucency (see page 126). A detailed scan is also performed at 18-20 weeks. Twins are more likely to have certain structural abnormalities, for example congenital heart disease and neural tube defects (such as spina bifida).
All twins are monitored at least every 4 weeks by ultrasound to look for growth restriction. This affects about 25 per cent of dichorionic twins and almost 50 per cent of monochorionic twins. The major risk to monochorionic twins, however, is the development of twin-twin transfusion syndrome.
Twin-twin transfusion syndrome
About 15 per cent of twins who share a placenta develop a condition known as twin-twin transfusion syndrome.
Coping with twins
Having two babies is especially exciting, and even a little awesome, for both you and the people around you. It can also be overwhelming at times. If you are carrying twins, it is important to have regular antenatal checks in order to identify any potential complications. Many obstetricians recommend iron and folate supplements to prevent anaemia.
Pregnancy symptoms are often more pronounced with twins and multiple pregnancies - for example, you may experience more sickness, fatigue, heartburn, haemorrhoids - because your body is working harder and carrying more weight than during a singleton pregnancy. You are also more likely to develop high blood pressure (hypertension) and you may need to give up work earlier - many women stop work at around 26 weeks of pregnancy. Do not worry - both you and your babies will be monitored closely throughout your pregnancy.
Since early delivery is much more common in twins and multiple pregnancies, you should visit the hospital to be checked over if you notice any hint of labour occurring. You are more likely to deliver early if you have a short cervix, and some hospitals offer a scan at 24 weeks to measure the length of this. Almost all twins are delivered in hospital and both of them are monitored continually throughout labour.
Take any opportunity to talk to others with twins for practical tips and advice. You could start attending a support group for the parents of twins, if there is one in your area, in order to build up a support network ready for when your babies are born.
It is even more important to maintain your energy levels by eating a healthy, balanced diet. It is often easier to digest small, frequent snacks than three main meals a day. Small meals, such as pasta or a jacket potato, based on slow-release carbohydrates will keep your energy levels higher for longer than a biscuit or doughnut, which will only give you a short 'sugar high'.
|Did you know?
The average length of a twin pregnancy is 36 weeks, and 34 weeks for triplets.
Tall women are more likely to conceive twins.
Women over 35 are more likely to have twins.
The highest rate of twins are born to Nigerian women.
Up to 22 per cent of twins are left-handed while for non-twins the rate is just under 10 per cent.
The United States has one of the highest rates for multiple births, while Japan has one of the lowest.