PrenatalSafe® Complete Plus

During pregnancy, the placenta sheds the baby’s (fetal) DNA into the mother’s blood. A blood sample is taken from the expectant mother. The circulating fetal DNA is isolated from the plasma component of the maternal blood and is then evaluated to determine the chance of having a baby with one of the conditions listed below.

It is important to note, that the Prenatalsafe® test is a screening test and is not a diagnostic test. If a high- chance result is obtained, the fetal medicine consultant will call you to discuss your options including diagnostic testing (chorionic villus sampling or amniocentesis).

The test will initially screen for:

• Down Syndrome (Trisomy 21)
• Edwards Syndrome (Trisomy 18)
• Patau Syndrome (Trisomy 13)
• Turner Syndrome (XO)
• Klinefelter syndrome (XXY)
• Jacobs Syndrome (XYY)
• Triple X syndrome (XXX)
• Rare Autosomal Aneuploidies = abnormalities involving all chromosomes besides 21,18,13,X and Y.
• Deletions and Duplications in any chromosome. These are missing or gained pieces of chromosomes (>7Mb)
• 9 different Microdeletion syndromes: 1p36 (1p36 deletion syndrome), 4p- (Wolf-Hirschhorn syndrome), 5p-(Cri-du-Chat syndrome), 15q11.2 (Prader-Willi / Angelman syndrome), 22q11.2 (DiGeorge syndrome), 8q24 (Langer-Giedion syndrome), 11q23 (Jacobsen syndrome) and 17p11.2 (Smith-Magenis syndrome)

The test will also screen for 45 ‘gene disorders’ including cystic Fibrosis, deafness, beta-thalassemia, sickle cell anaemia and other De Novo disorders. These results will be available 10 days following the initial chromosomal results.

DETECTED (High Probability/Chance)

Aneuploidy detected: indicates that the test has produced a result consistent with an aneuploidy of one (or more) of the chromosomes investigated. However, this result is not diagnostic and therefore does not guarantee that the fetus has the condition. Your consultant will call you to discuss the results in detail. The recommended follow-up is an invasive prenatal diagnosis test, such as chorionic villus sampling (CVS) or amniocentesis.

NOT-DETECTED (Low Probability/Chance)

Aneuploidy not detected: indicates that the test did not detect any aneuploidies for the chromosomes investigated. One of the major strengths of NIPT is the very high negative predictive value – which means that if you get a low chance result it is very unlikely that your baby will have one of the trisomies screened for. However, this result does not guarantee that the fetus does not carry these abnormalities.

INCONCLUSIVE RESULT (approximately 1%)

In certain cases where the sample did not pass the quality parameter thresholds, an inconclusive result is issued. In such cases, the expectant mother will likely be asked for a new blood sample in order to repeat the test. The re-test might still produce an “Inconclusive result” (in about half the cases) and a discussion with our specialist consultants is needed to determine the next steps.

The performance of the ‘chromosomal disorders’ part of the test has been assessed after looking at >71,000 pregnancies and follow-ups. This has been compiled in a document that is available upon request.

The performance of the ‘gene disorders’ part of the test is currently being reviewed and will soon be available. However, concordance with confirmatory tests for the De Novo conditions is 100% when an ultrasound finding has been detected/suspected. In the absence of ultrasound findings, concordance is observed to be ~70%.

The initial chromosome results will be available within 14 working days and one of our team members will call you as soon as the results are available and then email you a copy of the result. The 45 genetic disorders result will be ready in approximately 10 days after the initial chromosome results are available.