Twin pregnancy: having more than one baby

  • A ‘twin pregnancy’ is the term used when you are expecting two or more babies at the same time. It occurs in about one in 80 pregnancies.
  • Fertility treatment increases the chances of twin pregnancy.

  • At your early ultrasound scan which confirms whether you are carrying twins or triplets, it is important to find out the ‘chorionicity’ of your pregnancy.
  • This is to help identify whether your babies share a placenta and it is important because babies who share a placenta have a higher risk of complications.
  • This ultrasound is part of routine protocol at our SAAVI women’s hospital.

Placentation of Twins

Placentation of Twins

  • If your babies share a placenta, they are identical or ‘monozygotic’.
  • Most babies who do not share a placenta are non-identical or ‘dizygotic’.
Diamniotic-2 Eggs fertilised or 1egg splits soon after fertillisation within 1-3 days.

Diamniotic-2 Eggs fertilised or 1egg splits soon after fertillisation within 1-3 days.

Monochorionic-Diamniotic-Fertilised egg splits a little later within 4-8 days.

Monochorionic-Diamniotic-Fertilised egg splits a little later within 4-8 days.

Monoamniotic-Fertilised egg splits later with in 8 – 13 days.

Monoamniotic-Fertilised egg splits later with in 8 – 13 days.

Conjoined Twins-Fertilised egg splits later than the 13 Days.

Conjoined Twins-Fertilised egg splits later than the 13 Days.

  • Dichorionic diamniotic (DCDA) – if two eggs are fertilised or if one egg splits soon after fertilisation, each baby has its own placenta with its own outer membrane called a ‘chorion’ and its own amniotic sac.
  • Monochorionic diamniotic (MCDA) – if the fertilised egg splits a little later, the babies share a placenta and chorion but they each have their own amniotic sac; these babies are always identical.
  • Monochorionic monoamniotic (MCMA) – much less commonly, the fertilised egg splits later and the babies share the placenta and chorion and are inside the same amniotic sac; these babiesare always identical; this is rare and carries additional risks.

Types of Conjoined Twins

Types of Conjoined Twins

  • Twins that are physically joined at birth, sometimes sharing organs , and in some cases separable by surgery ( depending on the degree of fusion ).
  • Incidence:
  • Approximately 2/3rd of twins are dizygotic.
  • Birth rate of Dizygotic twins vary from 10 – 40 per 1000 birth.
  • Birth rate of Monozygotic twins vary from 2 - 3 per 1000 birth.

  • Most women who have a twin pregnancy have healthy pregnancies and healthy babies. However, complications are more common in twin pregnancy and having extra care during your pregnancy including more ultrasound scans reduces these risks to you and your babies.

For you

  • Minor problems that many pregnant women experience, such as morning sickness, heartburn, swollen ankles, varicose veins, backache and tiredness, are more common in twin pregnancies. They get better naturally after the babies are born.
  • Any problems that arise in any pregnancy are more common with twins and include:
    • Anaemia – this is usually caused by a shortage of iron because developing babies use up a lot of iron. Our nutritionist at SAAVI women’s hospital will help you for your diet need.
    • Pre-eclampsia – a condition that causes high blood pressure and protein in your urine.
    • A higher chance of bleeding more heavily than normal after the birth
    • A higher chance of needing a caesarean section or assisted vaginal delivery to deliver your babies.

For your babies

Prematurity

  • You are more likely to have your babies early if you are expecting twins or triplets:
    • About 60 in 100 sets of twins will be born spontaneously before 37 weeks of pregnancy
    • About 75 in 100 sets of triplets will be born spontaneously before 35 weeks
    • In comparison, only about 10 in 100 women who are pregnant with one baby will give birth before 37 weeks.
  • Babies born earlier than 37 weeks of pregnancy have an increased risk of problems, particularly with breathing, feeding and infection. The earlier your babies are born, the more likely this is to be the case.

Twin pregnancy and USG

Twin pregnancy and USG

Twin pregnancy and USG

  • Chorionicity is the main determinant of the perinatal outcome in twin pregnancies
  • Complications are significantly higher in monochorionic versus dichorionic twins.
  • Characteristics of the intertwine membrane is used to evaluate chorionicity.
  • “Lambda” appearance in dichorionic pregnancy
  • The typical “T” appearance in the monochorionic ones.
  • It is best seen in the first trimester (between 10-14 weeks)
  • The twin peak sign (also known as the lambda (λ) sign) is a triangular appearance of the chorion insinuating between the layers of the intertwin membrane and strongly suggests a dichorionic twin pregnancy.
  • The “T sign” is really the absence of a twin-peak sign (or lambda (λ) sign) and is used in ultrasound assessment of a multifetal pregnancy. It refers to the lack of chorion extending between the layers of the intertwin membrane, denoting a monochorionic pregnancy.

Twin-to-twin transfusion syndrome (TTTS)

  • Twins sharing a placenta (monochorionic pregnancies) also share the blood supply.
  • In around 15 in 100 monochorionic twin pregnancies, the blood flow may be unbalanced. We call this twin-to-twin transfusion syndrome (TTTS).
  • One baby, the ‘donor’, receives too little blood and has a low blood pressure while the other baby, the ‘recipient’, receives too much blood and has a high blood pressure.
  • You will be monitored with frequent scans for signs of TTTS. It can be mild and may not require any treatment, or it can be serious, in which case you will be offered treatment .

  • You may go into labour early with twin pregnancy. Even if you don’t, you will probably be advised to have your babies before your due date (elective birth). This is done either by having labour started off (induced) or by having a caesarean section.

  • As twin pregnancy have higher chances at pre mature birth you may be advised corticosteroid injection. corticosteroid in pregnancy

  • The exact timing of delivery for twin pregnancy depends on individual circumstances; however, if your pregnancy has been uncomplicated, it is advised that you should be offered spontaneous pain, to start.

  • If the baby nearest to the neck of the womb (often called the presenting twin) is head-down and you have no other complications then you should be able to have a vaginal birth if you wish. The position of your second twin can change after the first baby is born and should not influence how you choose to give birth.

  • If the baby nearest to the neck of the womb (cervix) is bottom-down (breech) towards the end of the pregnancy, a caesarean section is usually recommended.

  • These babies are usually delivered by caesarean section unless you are in very premature labour or you give birth to the first baby very quickly.
  • Your own preference is important and you should be given enough time to consider all of the relevant information before deciding what suits you best.

  • Monitoring your babies’ heartbeats during labour is recommended as it shows how well they are coping.
  • After your first baby is born, the cord will be clamped and cut in the usual way but the placenta will stay inside the womb until your second baby has been born.
  • Your doctors will check whether your second baby is coming head-first or bottom-first. As your second baby comes down the birth canal, the second bag of waters may be broken. A normal birth usually follows within about 30 minutes.
  • Although it is uncommon for the first twin to be born vaginally and the second to be born by caesarean section, it can occur if the second baby needs to be delivered urgently and/or a vaginal birth would be unsafe.

  • Breast milk is best for newborn babies and your body should produce enough milk for your babies. If you encounter difficulties, you can give formula.

  • Twins often come early and you will have a bigger bump than if you were having just one baby. You might consider stopping work early.

  • Twin pregnancy occurs in about one in 80 pregnancies.
  • It is important to check , whether your babies share a placenta , because babies who share a placenta have a higher risk of complications.
  • Conjoined Twins: ( Siamese twins )are – extremely rare
  • Extra antenatal checks and ultrasound scans to monitor your babies will be offered.
  • Common problems with twin pregnancies are anemia, high blood pressure (PIH). Early delivery of baby, bleeding during delivery and higher chance of cesarean
  • Most women with twin pregnancies will have a healthy pregnancy and healthy babies,

  • This information aims to helps you make the best decision regarding your care. It is not meant to replace advice from a doctor about your own situation.