16 – 32 weeks.
A premature birth screening, or preterm labour test, is actually a series of tests that combine to predict if you are likely to go into labour early.
It does not give a definite answer, but tries to identify low risk from high risk women and it can only be performed between 22 and 35 weeks of pregnancy.
A premature birth screening may also be called a preterm labour screening, preterm birth screening, early labour assessment, early labour prediction, preterm birth screening (PTBS) or premature baby prediction.
Am I at risk of an early delivery ?
Any woman can have a premature birth, but you may be at more risk if:
- You’ve delivered a preterm baby in the past
- You’ve had an operation on your cervix
- You are having more than one baby
It’s important to avoid a premature birth because premature babies are less able to cope with life outside the womb.
Around 6-10% of babies in the UK are born premature and out of all babies who die within the newborn period, 75% are premature. Prematurity is the main reason for admissions to neonatal intensive care units and is the leading cause of damage in newborn babies.
Signs of an early labour
These early signs of labour that may lead to a premature birth:
- A tightening or cramping pain that occurs every 10 minutes or more frequently
- Bleeding combined with a pink mucous discharge
- Back or pelvic pain which feels like downward pressure from your baby
If you are at all worried it’s important that you speak to your consultant or midwife.
What happens during the premature birth screening ?
During this appointment our fetal medicine specialist will:
- Analyse your previous medical and pregnancy history
- Discuss the possible outcome of the screening
- Perform an ultrasound assessment of your cervix
- Take a vaginal swab for fetal fibronectin
- Give you a detailed report from our Viewpoint Maternal and Fetal Database
- Discuss the findings with you
Predicting when a pregnant woman will go into premature labour is a complex process and some details in your medical history may provide the consultant with additional information that may influence your risk of a premature birth.
The Cervical Scan
Research has shown that if the cervical length shortens the risk of premature birth increases significantly. We measure the length of your cervix by an internal ultrasound examination, this allows for optimum accuracy in estimating the chance of early labour.
The Fibronectin Test
This test looks for the presence of a substance called fetal fibronectin in middle pregnancy. If fibronectin is present the chance of going into early labour rises. If fibronectin is not present the chance of early labour lessens significantly.
What happens if you get a positive result ?
Depending on your particular outcome from the premature birth screening, your obstetrician or midwife may decide to:
- Admit you to hospital
- Prescribe therapeutic steroid injections to help your baby prepare for premature birth