Ultrasound in Obstetrics Practise
Written by Dr. Ramesh Marimuthu
Is Ultrasound Safe for My Developing Foetus?
In modern day obstetrics, ultrasound has long been accepted as an integral part of routine antenatal care. Many researches and papers on this matter have been published. Ever since its use in the 60’s till now, it has been established to be safe to the developing embryo and foetus. There are potential thermal and mechanical hazards; however the modern ultrasound has not been found to cause any harmful effects to date. Importantly, the ultrasound should only be used when needed, conducted by a certified person and for the shortest time to reduce harm.
How Many Ultrasound Scans should I have in Pregnancy?
There are no definite answers. The schedule for ultrasound scan may vary from one centre to another. However there is four times in your antenatal period that you should seek for an ultrasound scan.
|Recommended Ultrasound Schedule||Gestation Weeks|
|Foetal Viability||6 – 10|
|Nuchal and Gross Foetal Abnormality||11 – 14|
|Detail Scan||18 – 23|
|Foetal Well-being||from 28 Weeks Onwards|
Most doctors will recommend an early scan as soon as you find yourself pregnant. This is done as early as 6 weeks to detect the foetal heart and establish viability. A second scan is recommended at 11-14 weeks to detect any gross abnormality and also to measure nuchal translucency. Nuchal translucency is an area at the neck of foetus. When measured, it can inform if the foetus is normally developing or otherwise. It is useful in detecting Down ’s syndrome. It is also during this time, an accurate assessment of gestational age and verification of EDD (expected date of delivery) is done.
A Detail Scan is done around 20 weeks or more gestation. It is detailed survey of almost every part of the foetus and will detect most of major structural abnormalities. The foetus is systematically viewed starting from brain, face, spine, heart, lungs, diaphragm, stomach, kidneys, bowel and the upper and lower limbs. We can also detect any major syndromes like Down’s from this scan by looking for soft markers. Soft markers are changes in the structure of the foetus when collectively give us clue of a syndrome.
Foetal well-being scan is undertaken at least once after 28 weeks to assess growth and foetal weight. It also conducted to determine placental localisation. This is usually done serially once a month or more frequently till delivery.
Dr. Ramesh is an Obstetrics & Gynaecologist (O&G) resident consultant at Nilai Medical Centre. He is passionate about his specialty and has special interest in reproductive medicine and emergency obstetrics. Dr. Ramesh’s clinic is open from Monday to Friday (9am – 5pm) and Saturday (9am – 1pm).