From double the overwhelm to double the excitement, finding out you are pregnant with twins can bring on a range of emotions but, what are the chances that you will be seeing double at your booking appointment?
A multiple birth is a pregnancy where you are carrying more than one baby; most commonly twins. There has been an upward trend in the numbers of multiple births over the last 20 years.
In 1984, 1 in every 100 pregnancies resulted in a multiple birth in the UK and now that has increased to 1 in every 65 (1).
What has caused the rise in multiple pregnancy?
There are a number of reasons why there has been a rise including (2):-
- an increase in the use of fertility treatments, such as IVF
- increased survival rates of premature babies due to advances in medical care and more knowledge about how we can prevent preterm birth
- Couples starting their families later in life
What are the different types of twins?
- Dichorionic diamniotic twins (DCDA) – each baby has a separate placenta and amniotic sac.
- Monochorionic diamniotic twins (MCDA) – the babies share a placenta but have separate amniotic sacs.
- Monochorionic monoamniotic twins (MCMA) – the babies share a placenta and amniotic sac
When do you find out if you are expecting twins?
You will usually find out for certain if you’re having twins at your first ultrasound scan. This is part of your routine antenatal care at around 11 to 14 weeks of pregnancy. However, you may already know that you are pregnant with more than one baby if you are going through IVF or you have an early pregnancy scan.
Identical or non-identical?
Whether the babies are identical or non-identical depends on how the babies are formed.
The likelihood of having identical twins is about 1 in 250 (or about 0.5%) (1). Known as monozygotic twins, a single egg is fertilised then splits into two (or in some rare cases three or more) soon after fertilisation creating identical babies with the same sex, DNA and physical features.
Complications of a twin pregnancy
If you are expecting twins, there are some complications that you should be aware of. It’s important to remember that most pregnant people carrying twins will go on to have healthy pregnancies and healthy babies.
Complications for you when having a twin pregnancy (3,4)?
- Increased pregnancy symptoms: double the babies can mean double the symptoms of pregnancy such as sickness, heartburn, breast tenderness, backache, pelvic pain and swollen legs
- Anaemia: having a twin pregnancy makes you more likely to develop anaemia, a condition where your body is short of red blood cells that carry oxygen around your body
- Pre-eclampsia: a condition that only pregnant women can get that causes a combination of raised blood pressure and protein in your urine. Some pregnant women expecting twins will be advised to take low dose aspirin if they have any other risk factors for pre-eclampsia
- Gestational diabetes: carrying a twin pregnancy will make you more likely to develop gestational diabetes and you will be offered a screening test for this
- Antenatal depression: If you are having a twin pregnancy you may have to cope with a difficult pregnancy, labour and birth which is you are more likely to experience antenatal depression. Depression in pregnancy is common and it should never be stigmatized. It’s important to tell your midwife or doctor how you feel so they can help you find treatment and support.
- Intrahepatic cholestasis of pregnancy (ICP): a liver disorder that can develop in pregnancy. This can be more common in twin pregnancies and the main symptom is itching, usually without a rash.
Complications during your labour (5)?
If you are carrying twins, it can make planning the delivery of the babies more complicated. Your doctor will discuss potential plans depending on the position of the babies and how many weeks you are when they are born.
If the babies are in a head-down position, you are likely to be offered an induction to help bring on your labour. If you are carrying twins it is more likely you will deliver by a caesarean section or have an assisted birth.
There is also an increased chance of bleeding more heavily than normal after birth.
Complications for your babies (6)?
Carrying twins can mean there can be complications for your babies including
- Growth: if you are carrying twins there is an increased chance the placenta will not work as efficiently as it should. This can affect the babies’ growth and development.
- Premature birth: most twins are born prematurely and this often happens spontaneously. You may be offered a medication called corticosteroids during your pregnancy to help your baby’s lungs develop more quickly. This can reduce the risk of complications associated with giving birth prematurely.
- Baby loss: sadly, losing a baby is more common if you are having a twin pregnancy. This is often because of complications such as chromosome abnormalities, complications of your babies sharing a placenta or if there is problems with the growth of one of your twins. It can be really difficult if you have another baby that survives and this can often cause a range of emotions that can be really difficult to cope with.
The complications associated with a twin pregnancy can sound scary but you should always be able to talk to the team looking after you about complications and your birth preferences. Remember that they are trained to deal with twin pregnancies and keep you and your babies safe.
Antenatal Care
Your care throughout pregnancy should be from a specialist team of doctors and midwives who are experts in managing twin pregnancies. This team can also include other members such as support from mental health professionals, physiotherapists and feeding specialists. This team should be able to advise you about:
- Your mental health and wellbeing during your pregnancy and after delivery
- Your nutrition throughout your pregnancy
- The complications associated with a twin pregnancy
- Your birth preferences
- How to feed your babies
Carrying a twin pregnancy can be rewarding but also challenging at times, often having to cope with a more difficult pregnancy, labour and delivery. There is treatment and support available for you to help you cope with a twin pregnancy and it’s important to let the team looking after you know how you are feeling.
References
1. Twins UK. Multiple Birth Statistics 2012. 2014; Available from: http://www.twinsuk.co.uk/twinstips/18/9934205/multiple-birth-statistics,-facts-&-trivia/multiple-birth-statistics-2012-%28released-2014%29/
2. Monden C, Pison G, Smits J. Twin Peaks: more twinning in humans than ever before. Hum Reprod. 2021;36(6).
3. Wang SS, Revels J, Dubinsky TJ. Double Trouble: Complications in Twin Pregnancies. Vol. 36, Ultrasound Quarterly. 2020.
4. Rauh-Hain JA, Rana S, Tamez H, Wang A, Cohen B, Cohen A, et al. Risk for developing gestational diabetes in women with twin pregnancies. J Matern Neonatal Med. 2009;22(4).
5. Jonsson M. Induction of twin pregnancy and the risk of caesarean delivery: a cohort study. BMC Pregnancy Childbirth. 2015;15(1).
6. Cheong-See F, Schuit E, Arroyo-Manzano D, Khalil A, Barrett J, Joseph KS, et al. Prospective risk of stillbirth and neonatal complications in twin pregnancies: Systematic review and meta-analysis. BMJ. 2016;354.