Ultrasound scan in pregnancy

Ultrasound has been used in obstetrics for more than thirty years. Evidence suggests there are no harmful effects on the human fetus. Most importantly, the ultrasound baby scan should only be used when there is an indication and that the fetus should be exposed to a pregnancy scan for the shortest duration of time as possible.

 

Early Pregnancy scan (6-10 weeks gestation)
An early pregnancy scan is usually done soon after a woman knows that she is pregnant. The baby scan is done to confirm that the woman is pregnant and that the pregnancy is inside the womb(intra-uterine pregnancy) and not outside the womb(ectopic pregnancy) and to diagnose if a miscarriage has occurred. It is performed to confirm that the fetus, if already formed, is viable and has a heart beat and to estimate the gestational age of the fetus. Multiple fetuses can sometimes be diagnosed at this scan.

 

Nuchal Thickness scan (11-14 weeks gestation)
The nuchal scan is done to assess the risk of Down’s Syndrome by measuring the thickness of the fat pad behind the fetus neck and to identify the nasal bone. Major fetal abnormalities can be detected during the scan.

 

Detailed Anomaly Scan (18-23 weeks gestation)
The detailed baby scan is performed to determine if the fetal structures are normal and to identify fetal abnormalities, in particular, in the fetal brain, spine, heart, gut and limbs.The position of the placenta is determined accurately during the scan.

 

Fetal Growth and Health scan (26 weeks gestation onwards) 

The scans for the rest of the pregnancy is concerned in assessing fetal growth and well-being and ensuring the fetus is developing normally and healthily.

Doppler assessment of fetal vessels may be needed if there is cause for concern regarding fetal growth and well-being.

Newer technology with 3D/4D baby scans allow accurate visualisation of the fetal face and fetal spine.