Finding out you are pregnant with twins can be an exciting and stressful time.
Twin pregnancy brings with it many variables, least of all the possibility you will meet your babies early.
If you are pregnant with twins, there is a good chance you will give birth early.
It’s estimated around 60% of twins are born before 36 weeks gestation, a month earlier than the average 40 weeks gestation of a single baby.
Most twin births are planned, meaning labour is induced or the babies are born via c-section, yet this brings with it the risk of complications due to premature birth.
When Is The Best Time For Twins To Be Born?
So, when is the right time for twins to be born? Firstly, here’s an explanation as to why twins can be born early.
Why Are Twins Born Early?
The average twin pregnancy lasts around 35 weeks. Some women carrying twins will go into labour spontaneously, and others will need to have their babies early due to increased risk of complications.
The reason for early spontaneous labour with twins is not well understood but it’s believed to be due to the increased size of the uterus. Like all muscles, the uterus will tend to contract as it is stretched. With twin pregnancies, the uterus is stretching considerably more and earlier than with a singleton pregnancy.
When there are concerns about the health of mother or of the babies, the risk of premature birth may be weighed against the risks to continuing the pregnancy with complications.
Increased risks for premature birth include:
- High blood pressure or preeclampsia
- Gestational diabetes
- Preexisting diabetes
- Maternal infections
- Placental bleeding (previa or abruption)
- Reduced placental function
- Premature rupture of membranes
- Fetal abnormalities
- Intra-uterine growth restriction (IUGR)
- Monochorionic pregnancy (twins who share a placenta)
- Twin to twin transfusion syndrome (TTTS)
There is a slightly increased risk of stillbirth for twin pregnancies compared to singleton pregnancies. For singleton pregnancy, the stillbirth rate is around 5 per 1,000 births, for twins the rate is around 12.3 per 1,000 births.
What Are The Current Recommendations?
Women who are pregnant with twins are usually told their babies need to be born early to reduce the risk of stillbirth or neonatal death.
Yet the optimal gestational age for twin birth has not been known. Most recommendations range from 34 to 39 weeks. This is because the risk of stillbirth begins to increase after 39 weeks.
Most countries recommend a planned birth for twins, either by induction of labour or elective c-section. The main problem with early birth is the complications that can occur as a result of premature birth.
Babies who are born early may experience the following short term problems:
- Low birth weight
- Respiratory problems
- Heart problems
- Brain injury
- Inability to regulate temperature
- Gastrointestinal problems
- Blood problems (jaundice or anaemia)
- Low blood sugar
- Low immune system.
Premature birth can lead to longer-term complications, such as:
- Cerebal palsy
- Vision and hearing loss
- Delayed cognitive skills
- Behavioural problems
- Chronic health problems (asthma, infections)
- Increased risk of SIDS.
Is 36 Weeks Optimal For Twins?
A study published in the British Medical Journal has reviewed 32 studies and determined there is no evidence to support planned delivery of twins before 36 weeks.
The review looked at over 35,000 twin pregnancies in order to find out if there is an optimal gestational age for birth. The data included 29,685 dichorionic pregnancies (each twin has individual placenta) and 5,486 monochorionic (twin shares a single placenta).
The study data showed in dichorionic pregnancies the risk of stillbirth and neonatal death didn’t change until 37 weeks gestation. If birth was delayed for one extra week (to 38 weeks) there was an additional 8.8 perinatal deaths per 1000 pregnancies.
For twins sharing one placenta there was no clear evidence to support planned birth before 36 weeks gestation.
This new information will help efforts to reduce the stillbirth rate in twins while lowering the risk of complications due to premature birth. If you’re pregnant with twins ask your care provider about the risks and benefits of birth choices as well as timing for birth. This will enable you to make an informed decision about your pregnancy care and birth plan.