Pregnancy scans provide useful medical information to date the pregnancy, to detect multiple pregnancy, viability of pregnancy, detect ectopic pregnancy, ovarian cyst, localise placental position, growth and size of the foetus, presentation of the foetus prior to delivery and may detect some foetal structural defects, although it is not possible using ultrasound scan to detect all structural abnormalities prior to birth.

Even when foetal structural abnormalities are present at 17 to 20 weeks, or beyond 20 weeks, for example, spina bifida, heart defects, cleft lip-palate, finger or toe abnormalities may not be detected on ultrasound scan until the baby is born.

An increasing number of pregnant women have an ultrasound scan done between 11 weeks 3 days to 13 weeks 6 days to measure the nuchal translucency (soft tissue/ fluid at the back of the foetal neck ) to determine the risk of Down’s syndrome. This test is done in conjunction with a sample of blood drawn from the forearm vein of the pregnant woman between 9 weeks to 12 weeks (maternal serum screening for free beta-hCG and PAPP-A levels). The combined test of ultrasound scan and blood test may be able to detect 9 out of 10 unborn babies with Down’s syndrome.

Amniocentesis done at 16 weeks, by inserting a needle under ultrasound scan control into the amniotic sac to test the chromosomes, is a more accurate and reliable test for diagnosis of Down’s syndrome. The clinic at COGUS performs amniocentesis.

COGUS is accredited to perform such nuchal translucency measurement, holding the certificate of competence for ultrasound examination at 11 to 14 weeks, issued by the Foetal Medicine Foundation, London and Royal Australian and New Zealand College of Obstetricians and Gynaecologists.

Pregnancy scans are performed by scanning on the skin of the abdomen with a partially filled comfortable urinary bladder. More detailed and accurate medical information about the pregnancy can be obtained by vaginal ultrasound (called TVS, Trans Vaginal Scanning) below 14 weeks pregnancy. TVS is safe, painless and does not harm the pregnancy. A pregnant woman may choose not to have vaginal scanning during pregnancy. In later pregnancy, a vaginal scan may be needed to identify the location of the placental margin in relation to the cervix, for a suspected low lying placenta (placenta praevia).