Group B Streptococcus Testing Information
Group B Streptococcus (GBS) is the most common cause of life threatening infections in new born babies in the UK
What is Group B Streptococcus (GBS)?
Group B Streptococcus (GBS) is the UK’s most common cause of life threatening infections in new born babies, and of meningitis in babies up to age 3 months.
Most GBS infections can be prevented by giving antibiotics intravenously (through a vein) at the onset of labour to all women that carry GBS. UK guidelines recommend mums should be offered these antibiotics in labour if GBS has been detected during the current pregnancy, if a previous baby had GBS infection or if she has a fever in labour. Other risk factors include labour starting or waters breaking before 37 completed weeks of pregnancy and waters breaking more than 18 hours before birth.
Intravenous antibiotics in labour are highly effective at preventing GBS infection in new born babies, reducing the risk for a baby born to a women carrying GBS from around 1 in 300 to less than 1 in 6000. Oral antibiotics should not be given during pregnancy for GBS carriage as they have not been shown to reduce GBS infection in babies.
There are always small but potentially serious risks associated with taking antibiotics, and this needs to be fully discussed with your doctor or midwife.
Detecting a GBS carrier
Screening for GBS is not routinely offered in the NHS. Laboratory testing of GBS is routinely undertaken at the Laboratory we send the samples to.
Two swabs (lower vaginal and rectal) need to be cultured, ideally in the last five weeks of pregnancy, to best predict GBS carriage around the time of delivery. The swabs will be taken by yourself in privacy.
When the ECM test is properly performed within 5 weeks of giving birth, a negative result was shown to be 96% predictive of not carrying GBS at delivery (4% of women acquired carriage between the test and birth) and a positive result 87% predictive of carrying GBS at delivery (13% of women lost carriage in that time). The test can be done earlier, but isn’t as reliable at predicting carriage status over longer periods. It can be done later, but the chance of the baby arriving before the result increases.
The results of the test takes between 3-5 days to be returned. This will be sent to you via a text message to show if the test is positive or negative. In the result of a positive test, you will need to let you GP/Midwife know as soon as possible. It is also advised to present this information as soon as you go into labour, so the antibiotics can be arranged for you.
Price- £49 week days and £59 on an evening or weekend
The IONA® test
The IONA® test is a non-invasive prenatal test for pregnant women which estimates the risk of a foetus having Down’s syndrome (T21), Edward’s syndrome (T18) and Patau’s Syndrome (T13). The IONA® test can now also test for XY chromosomes to determine the baby’s gender if required.
The IONA® test is an advanced screening test carried out on a small blood sample taken from the mother’s arm with no risk of miscarriage.
Why choose to have the IONA® screening test- NIPT?
Traditional screening that is offered by the NHS during pregnancy is currently called the combined test. This is an ultrasound scan to measure the nuchal translucency (NT) and a blood test. This is much less accurate than NIPT and it only detects around 85% of babies with Down’s syndrome.
The IONA® test has a higher detection rate than the current combined test offered to pregnant women. This means that fewer pregnant women will undergo unnecessary invasive follow-up procedures such as amniocentesis or CVS (chorionic villus sampling) which are stressful, painful and can carry a small risk of miscarriage.
- Safe: non-invasive with no risk of miscarriage
- Fast: results available in 3-5 working days
- Accurate: greater than 99% at detecting trisomy conditions (trisomy 21, 18 and 13) and greater than 97% at detecting fetal sex (optional)
- Local: the IONA® test is performed in a laboratory local to you, not shipped to US or China
- Quality: the IONA® test is a regulated screening test which is CE markedFrom 10 weeks gestation a small blood sample is taken from the mother’s arm and sent to a local laboratory for analysis with the IONA® test. The DNA from the mother’s blood is extracted and the test is performed on the small amount of DNA. During pregnancy, the placenta leaks fetal cell-free DNA which circulates in the maternal bloodstream. As a result, a maternal plasma sample contains a mixture of fetal and maternal circulating DNA. The IONA® test directly measures the amount of cell-free DNA and can detect small changes in the DNA ratio between the maternal and cell-free DNA when a fetal trisomy 21, 18 or 13 is present.
- How are the IONA® results reported?
- The IONA® Software for analysis calculates the relative amount of chromosomes 21, 18 and 13 to calculate a likelihood ratio to predict the presence of a trisomy. This figure is then combined with the mother’s age to calculate the probability of the foetus being affected.
- How the test works
- Low Risk: means that it is very unlikely your pregnancy is affected by trisomy 21, 18 or 13.
- High risk: means that your pregnancy is at increased risk for trisomy 21, 18 or 13 and the result should be confirmed by a follow up invasive such as amniocentesis.
- No result: Very occasionally there is insufficient placental DNA in the sample to obtain a result. Women may be asked back by your healthcare provider for a further blood sample.
For further information please visit www.the-iona-test.com
Price- £439 week days and £449 on an evening or weekend