All parents want to believe that their pregnancy and baby will be perfect but want to be assured that it is so indeed. Prenatal investigations which include the use of ultrasound, biochemical markers and hormonal tests are used to achieve this aim. These investigations will also prompt the obstetrician to optimise the obstetrics antenatal care or suggest further diagnostic procedures as and when needed.
There are a variety of non-invasive and invasive techniques available:
Knowing about problems (if any) before the baby is born can help parents make decisions about the pregnancy. Certain problems can be treated before the baby is born, while others may need special treatment right after delivery.
This test is widely recommended by Colleges of Obstetricians & Gynaecologists in Singapore , United Kingdom, United States, Australia and most countries as an effective way of assessing the risk of a foetus having Down Syndrome or other common chromosomal disorders eg, Tri 13 or 18, This screen combines a high resolution ultrasound scan with screening of a maternal blood sample, and is done between 11 and 14 weeks of pregnancy. This screen is approximately 90% sensitive.
This is most sensitive screening test for Trisomy 21,13 and 18 currently as it is 99% senstive. It utilises the free fetal DNA present in the mother’s circulation to determine whether there is excessive DNA present to confirm the presence of a karyotype. The blood test can be drawn from the mother as early as 10 weeks and the results will be returned at the 12 weeks gestation where a nuchal and early fetal anomaly scan should be performed.
Carried out between 6 to 10 weeks, the fetal viability scan is an extremely useful test for patients who have had previous miscarriages or who are experiencing pain and/or bleeding. At this stage in pregnancy, it is possible to confirm the presence and number of live fetuses and determine the location within the uterus using the trans-vaginal or abdominal approach.
A fairly short procedure, this scan aims to make measurements which accurately predict the due date of the baby. This can be done from 8 to 20 weeks, but dating is more accurate when the scan is done before 14 weeks than afterwards.
To examine the fetal anatomy and assess normal growth, and check the placental position and cervical status. This scan, carried out between 20 to 24 weeks, can detect up to 90% of significant abnormalities.
Measuring the cervical length gives an indication of the risk of preterm labour and is best incorporated into the Fetal Anomaly Scan. Early detection of those at risk may help to avoid preterm labour by active intervention.
This scan, which is done from 24 to 41 weeks, aims to assess the baby's growth and evaluate the placental location, amniotic fluid volume as well as fetal movements. Blood flow from the placenta to the baby is also assessed with the use of colour Doppler ultrasound.