VIABILITY SCAN

A viability scan is an early scan to confirm pregnancy, and is most commonly requested by women who have missed a period and suspect that they may be pregnant or upon a positive pregnancy test. Scans may be undertaken from 5 weeks onwards and may show only a gestational sac in the very early pregnancy (5 weeks) or a fetal pole (6 weeks), or a measurable length of the fetus from 7 weeks onwards. For a pregnancy to be called ‘viable’, a fetal heart beat must be identifiable on the scan.

Where there is a fetal pole within the uterine cavity but no fetal heart activity, the pregnancy is deemed ‘non viable’ or a miscarriage, and management would depend on symptoms and gestational age, and could be either conservative, medical or surgical.

DATING SCAN

A dating scan is requested and performed, usually when there are uncertainties about the last menstrual period, especially when cycles have been irregular or when the period dates cannot be recalled with certainty. A dating scan is best done at and after 7-8 weeks when the fetus can be measured accurately and the age of the pregnancy established reliably.

An early scan can also show more than one fetus, and can confirm twin pregnancy, and is helpful if there is a family history of twins.

FETAL GROWTH SCAN

A fetal growth scan involves measurements of certain vital fetal structures, and comparing them against a range expected at the stage of pregnancy. When several growth scans are performed at regular intervals, an accurate track of baby’s growth can be obtained, and the birth weight can be predicted. In addition the amniotic fluid volume and placental site are noted and documented. At Women’s Health Care Ltd., we also look at functional well being at every growth scan. Fetal breathing and truncal movements, limb and eye movements are noted. Blood flow in the umbilical artery and other fetal blood vessels are identified and measured. The structural and functional findings help in assessing fetal growth and well being.

DOPPLER ULTRASOUND

Doppler ultrasound measures blood flow in blood vessels.

At Women’s Health Care Ltd., Doppler ultrasound measurement of blood flow in the fetal umbilical arteries is done routinely as part of the fetal growth scan. Doppler assessment of blood flow in uterine arteries at 24 weeks help in predicting a small baby or pre-eclampsia.

ANATOMY SCAN

This is a detailed scan conducted between 20 to 21 weeks to examine the baby’s anatomy. The fetal structures are surveyed according to an agreed checklist; in addition the amniotic fluid and placental site are noted and documented. The baby’s measurements are noted and compared with expected values. Usually, the scan takes about 20 minutes and is completed in one sitting, but sometimes the baby’s position might preclude good views, and the scan may take longer to complete.

EARLY ANATOMY SCAN

An early anatomy scan is done at about 16-18 weeks to have an early assurance of  baby’s normal development. It is exactly like the standard 20 week scan looking at the baby’s anatomy. The only structure that should have a later confirmation is the fetal heart which may not be seen and assessed reliably at 16-18 weeks. Parents find a normal fetal scan at 16 weeks very reassuring, and find it easier to relax for the remainder of the pregnancy.

CERVICAL SCAN

The cervix is often measured during pregnancy as it becomes shorter when there is a risk of preterm labour. Women who have had a previous preterm birth or have an irritable uterus are at increased risk of an early labour and delivery. A cervical length scan measures the length of the cervix, and can help in predicting preterm labour. This is done by using an internal probe (transvaginal scanning) to identify the upper and lower ends of the cervix to obtain an accurate measurement.