Dating and Viability Scan
A dating scan is performed in order to establish the gestational age of the pregnancy and is accurate to within 3 days. Dating scans also reveal other important information such as the location of the pregnancy, the number of embryos in the uterus, the presence of a heart beat in the embryo (viability), the length of the embryo (this will establish the dating of the pregnancy) and the presence of uterine fibroids or ovarian cysts in the pelvis.
11-14 Week Scan with Downs Syndrome Risk Assessment
The best time to perform this scan is at 13 weeks. The scan, which is usually done transabdominally, but occasionally it may be necessary to do the scan transvaginally, assists to date the pregnancy accurately, to diagnose a multiple pregnancy, to diagnose certain major fetal abnormalities, to assess the risk for Down Syndrome and other more rare chromosomal abnormalities (Edward Syndrome, Patau Syndrome, Turner Syndrome and Triploidy) with nuchal translucency measurement.
20 to 22 Week Anomaly (Detail) Scan
This is a routine examination performed at 20-22 weeks. In our practice the vast majority of patients have had an 11-14 week scan which has already determined the number of babies present, estimated due date and risk of Downs Syndrome and early anomaly scan.The scan at 20-22 weeks is more to assess and evaluate the fetal brain, face, spine, heart, lungs, stomach, kidneys, bladder, cord insertion at the belly button, arms and legs, placenta position, length of the cervix and amniotic fluid volumes. The fetal position and size of the maternal abdomen are important factors that affect fetal anomaly detection. The gender of the fetus can often be determined on this scan.
Fetal Echocardiography (Heart Scan)
This scan is offered as part of the 20-22 week scan. Heart abnormalities affect 1:100 babies and the vast majority of cardiac abnormalities (75%) can be detected at 20-22 weeks by sonologists trained in fetal cardiac scanning. We recommend this scan for women with a family history of heart abnormalities, previous baby affected by a heart abnormality, or where increased nuchal translucency had been found at the 11-14 week scan.
Fetal Growth and Well Being Scans
Your obstetrician may refer you for a scan in the third trimester for a variety of reasons – for example, if you are clinically too large or too small for dates, have vaginal fluid loss, have premature contractions, high blood pressure, pain in the abdomen or diabetes. This scan aims to determine the growth and health of the fetus by examining the movement of the fetus, the measurements of the size of the fetal head, abdomen and thigh bone and calculation of an estimate of fetal weight, measuring the amount of amniotic fluid and evaluating the placental position and appearance as well as assessing blood flow to the placenta and fetus by colour Doppler ultrasound.
This scan assesses the development and well-being of the fetuses in a twin pregnancy and whether you are carrying Dichorionic Diamniotic (DCDA) twins - who have 2 placentas and 2 separate sacs; Monochorionic Diamniotic (MCDA) twins - who have a single placenta and 2 separate sacs; or Monochorionic Monoamniotic (MCMA) twins - who have a single placenta and both babies are moving around within the same sac. Some special problems may be encountered during a twin pregnancy, such as premature labour, growth restriction of one or both fetuses and low birth weight, twin-twin transfusion syndrome, cord entanglement and conjoined twins.