In 2013, 114 sets of twins were born at the Rosie - which is about one in 50 births.

Triplets occur naturally in approximately one in 10,000 pregnancies (the Rosie welcomed three sets of triplets in 2013), and quadruplets are even rarer. Nowadays, the treatment of infertility has made multiple births more common.

There are three types of twin pregnancy. The biological principles are the same for triplets, though these are more complex than with twin pregnancies.

Identical twins

Identical (monozygotic) twins occur when a single egg (zygote) is fertilised. The egg then divides into two, creating identical twins who share the same genes as one another. Identical twins are always the same sex, so if your twins are identical you'll have two girls or two boys, and they'll look very alike. 

Non-identical twins

Non-identical (dizygotic) twins occur when two separate eggs are fertilised and then implant into the woman’s womb (uterus). These non-identical twins are no more alike than any other two siblings. Non-identical twins are more common. The babies may be of the same sex or different sexes. One-third of all twins will be identical and two-thirds non-identical.

If your babies share a placenta they will be identical. If they have two separate placentas they may or may not be identical:

  • Dichorionic diamniotic (DCDA) twins have their own separate placenta with its own separate inner membrane (the amnion) and outer membrane (the chorion)
  • Monochorionic diamniotic (MCDA) twins share a single placenta with a single outer membrane and two inner membranes
  • Monochorionic monoamniotic (MCMA) twins share both the inner and outer membranes

If you are pregnant with twins (or more) a plan of care will be made for you which will involve consultant led care. This means that you will be offered visits to the Rosie hospital for antenatal checks and ultrasound scans on an increasingly regular basis. During these antenatal checks we will closely monitor the health of both you and your babies. 

Be prepared

It is quite normal for twins to be born around two to four weeks prior to your due date (36 to 38 weeks of pregnancy) and for triplets around four to eight weeks early (32 to 36 weeks of pregnancy). It is therefore advisable to be as prepared as possible. 

Try to gather as much information as you can regarding caring for twins or triplets, and think about the impact of having two or three babies to look after at the same time. Come to the Rosie twins night, join a local twins club and find out about Tamba (Twins and Multiple Birth Association). Speak to your community midwife for advice and see the other useful contacts below.


When thinking about the timing and safest way for your babies to be born, there are many factors which must be considered and these will be discussed with you when you see an obstetrician in the antenatal clinic. This will help you to make an informed decision about which way your babies will be delivered and the best time in your pregnancy for this to happen.

It is usual for triplets to be delivered by a planned caesarean section between 34 and 36 weeks of pregnancy. 

With an uncomplicated twin pregnancy, women are given the option of an induction of labour at around 38 weeks of pregnancy, or to await natural, spontaneous labour. However, approximately 4 out of every 10 sets of twins are born before 37 weeks. 

Your obstetrician may suggest that your babies are born by caesarean section. The reasons for a planned or ‘elective’ caesarean section will be discussed with you and you will be offered information on all the risks and benefits of this mode of birth. 

Your Babies

Babies born after 37 weeks of pregnancy will usually just need time and patience to establish feeding. If your babies are born before 37 weeks they are considered to be preterm, and they may need care on the neonatal unit immediately after birth. Unfortunately, this may involve a short period of separation from you, but when you have had time to recover from the birth and no longer need to be cared for on the delivery unit you can be taken to be reunited with your babies. 

There is a lot you can do to help your babies, please speak to your midwife if you wish to breastfeed and the earlier you are able to start to do this, the better your milk supply will be.

You will be fully informed and involved with the care of your babies wherever they receive their care but please be aware that each baby is considered as an individual and it is possible that they may need different care in different places. 

The length of your postnatal stay is variable. It depends on how many weeks pregnant you are when your babies are born and what type of birth you have had. It is possible that your babies will need to stay in hospital longer than you.

The Rosie twins night

This is an evening meeting led by a midwife and held at regular intervals during the year. It is a structured but informal evening to discuss the many aspects of having twins/triplets. Dates of meetings are displayed in antenatal clinic, or you can enquire at Rosie reception.

Booking is essential. Please telephone: 01223 217 617.

Resources on other sites: