Your baby is our second patient, as important to us as you and your partner. Over the years, we have developed expertise in evaluating the fetus for health and wellbeing. This allows us to guide you through the pregnancy to make the correct choices about when, where and how to deliver your baby. We will explain the value and meaning of each fetal assessment tool, and recommend the most suitable path to assess the health and wellbeing of your unborn baby.
The clinic offers one of the most comprehensive range of services for fetal assessment and therapy which includes fetal growth scans, Non-invasive prenatal testing, Cardiotocograms (CTG), Amniotic fluid index (AFI) and Doppler, Immune modulation and hormonal therapy and Intrauterine fetal therapy.
PRENATAL SCREENING & DIAGNOSIS SERVICES
Most babies born are healthy, and there is often no need for concern. However, most parents want some reassurance that their unborn baby is not suffering from various possible birth defects, such as physical deformities, chromosomal abnormalities and genetic diseases. Many defects can be discovered during pregnancy by one or more prenatal tests,
In most cases, prenatal testing is reassuring, and it allows parents to continue to enjoy their pregnancy and bond with their unborn baby.
1. Dating Scan
One of the most important things to know about your baby is her ‘dates’. This means how old your baby is. By convention we measure your fetus’ age from the first day of your last normal menstrual period. It IS an important estimate on which many decisions about your baby will depend, such as when to perform the nuchal translucency scan, when to do the amniocentesis, and when to deliver the baby.
The dating scan accurately determines the fetal age, but at this scan important additional information can be gathered such as the viability of the fetus, the number of fetuses, and in the case of twins whether they’re fraternal or identical twins. A slow fetal heart rate in pregnancy may indicate a higher risk of miscarriage, but a good, fast fetal heart rate in early pregnancy suggests a very good chance that the pregnancy will continue nicely.
2. Non Invasive Prenatal Screening
Prenatal testing includes both screening tests and diagnostic tests. Screening tests are non-invasive and usually involve a simple blood test and an ultrasound scan.
Research has led to new advances in Non Invasive Prenatal Screening. Non-invasive for prenatal care means no deployment of any invasive means near the fetus, more specifically, no needling near the fetus.
In the pregnant mother’s blood circulation are free DNA molecules – and about five per cent of that free DNA is derived from fetal cells. This is called Cell-free DNA (cfDNA) and given that they are actual fetal fragments of DNA circulating in the pregnant mother’s blood, they are considered to be a more direct and accurate form of obtaining information on the fetus, as opposed to visual screening methods such as ultrasound, which is reliant on the skill of the operator.
The test involves taking a small blood sample form the mother at 10 weeks gestation onwards. Results are usually returned within 2 weeks.
The Non Invasive Prenatal Test (NIPT) is able to detect chromosomal abnormalities in the fetal cfDNA fragments with 99.96% accuracy, rendering it a near diagnostic.
Non Invasive Prenatal tests are quickly being adopted as they have a detection rate of 99% for Down Syndrome, Edwards Syndrome and Patau Syndrome. NIPT can also detect sex chromosome abnormalities such as Klinefelter Syndrome, Turner Syndrome and Jacobs Syndrome.
To date, these new tests such as iGeneScreen and MaterniT21 have significantly reduced the number of invasive diagnostic tests such as Amniocentesis and Chrorionic Villus Sampling (CVS). These invasive tests carry a risk of miscarriage of about 1 in 100.
3. Nuchal Translucency (NT) Scan
The Nuchal Translucency scan is usually done between the 11th and 14th week of pregnancy. This test can estimate the likelihood of a baby having Down syndrome (Trisomy 21) and identifies women who should be offered further testing.
The nuchal translucency is a pocket of fluid at the back of the baby’s neck, which can best be seen between the 11th and 14th weeks of pregnancy. Babies with Down syndrome tend to have a larger collection of fluid than healthy babies. Using ultrasound, the amount of fluid is measured and this measurement is fed into a computer, along with the mother’s age to compute the risk of the baby having Down syndrome at the time of the clinic visit.
4. Combined Test
Nuchal Translucency (NT) Scan + First trimester serum screen
In this test, the results of the NT Scan are combined with the blood results of two pregnancy specific hormones: b-human chorionic gonadotrophin (b-hCG) and pregnancy-associated plasma protein A (PAPP-A).
Other tests are being developed to enhance the non-invasive detection of Down syndrome such as nasal bone evaluation, blood flow in specific fetal vessels (ductus venosus) and more serum markers, but these are not yet in routine clinical practice.
5. Triple Test & Quadruple Test
Triple tests and quadruple tests are blood tests that measure similar biochemical substances in mother’s blood: alphafetoprotein (AFP), human chorionic gonadotropin, unconjugated estriol, and inhibin A. The first three are measured in both tests; inhibin A is included in the quadruple test. Both tests are usually performed between the 15th and 22nd week of pregnancy, however the earlier the better.
High levels of AFP could indicate that the fetus has a neural tube defect such as spina bifida or anencephaly. Low AFP levels, on the other hand, and abnormal levels of human chorionic gonadotrophin could indicate that the fetus has chromosomal abnormalities such as Down syndrome (Trisomy 21) or Edward syndrome (Trisomy 18).
The triple and quadruple tests are screening tests. Like all screening tests, these tests can only indicate that the fetus may have a problem. Further testing, by invasive prenatal methods are necessary to confirm any abnormality.
Amniocentesis is a prenatal diagnostic test that’s carried out between the 15th and 20th weeks of pregnancy.
The amniocentesis procedure involves a fine needle being inserted into the fetal amniotic sac to obtain up to 20 ml of amniotic fluid for analysis. The amniotic fluid is analysed for fetal cells and fetal DNA to study chromosomal and genetic disorders such as Down syndrome, thalassemia and cystic fibrosis.
This is a highly versatile test that can also detect many other genetic disorders. These days however, mothers over the age of 35 are increasingly opting for non-invasive prenatal testing as a first option, and will do an amniocentesis only if they find that the test returns a positive for abnormality.
Amniocentesis results take between 8 to 21 days to be ready. Modern molecular technologies such as AmnioPCR (or QFPCR) now allow some results to be available within 48 hours (unless it’s over a weekend), and even newer techniques have been developed that allow laboratory testing to be completed within two hours. FlashFISH™ technology allows, for the first time ever, Same Day Prenatal Diagnosis.
Amniocentesis is associated with a small, but not insignificant, risk of fetal miscarriage of about 1%.
7. Chorionic Villus Sampling
Chorionic villus sampling (CVS) is another invasive prenatal diagnostic test that is usually carried out between the 11th and 13th weeks of pregnancy. At CVS, a fine needle is inserted into the placenta and a tiny piece of the placenta (chorionic villus) is obtained for analysis.
Just as with the amniocentesis, CVS is carried out to obtain fetal cells and fetal DNA to study chromosomal and genetic disorders such as Down syndrome, thalassemia and cystic fibrosis. Similarly as well, it also is a highly versatile test that can detect many other genetic disorders.
This test is usually recommended for pregnant women known to be at increased risk for chromosomal and genetic disorders such as Down syndrome and thalassaemia. CVS is associated with a slightly higher risk of fetal miscarriage of about 1.3% – 2%.
This diagnostic test, which examines blood from the fetus to detect fetal abnormalities is also known as fetal blood sampling and percutaneous umbilical cord blood sampling (PUBS).
Using ultrasound to determine the location where the umbilical cord meets the placenta, or the fetal liver, a thin needle is inserted into the umbilical cord to collect a small sample of fetal blood.
This procedure, which is similar to amniocentesis except that fetal blood is retrieved instead of amniotic fluid, is generally performed after the 20th week of pregnancy.
Like amniocentesis, cordocentesis tests for chromosomal abnormalities and blood disorders. Cordocentesis can also help diagnose fetal anaemia and Rh isoimmunisation. The risk of miscarriage related to cordocentesis is about 2%.