Importance Of Level II Ultrasound Scan ( Anomaly Scan)
What is the Level II ultrasound scan
The vast majority of babies are normal. However all women, whatever their age, have a small chance of delivering a baby with structural abnormalities that cause physical or mental limitation. Many such abnormalities can be diagnosed and ruled out with the fetal anomaly scan.
This is a detailed scan done at 18-20 weeks during which each part of the fetal anatomy is examined to see if the baby is developing normally. Special attention is paid to the fetal structures like brain, spine, face, stomach, bowel, kidneys, urinary bladder and limbs.
In addition to these structures fetal growth, the position of the placenta, amniotic fluid, the umbilical cord, fetal tone, fetal movements and cervical canal are also assessed.
What are the indications of Level II scan
Now a days with the advancement of the medical field it is a routine to get level II USG for all the expecting mothers whether there is any history of any congenital abnormality in previous issues or not. Even If you had a first-trimester (level 1) sonogram as part of a first-trimester screening test, the more detailed level 2 sonogram is important because of all the additional valuable information it gives your practitioner about what’s going on with your baby.
In Indian setup, the level II scan is done between 18-20 weeks. It is advisable to get it done at 18 weeks so you have a window of 2 weeks to get any additional tests done like a quadruple marker or a review USG in higher centers in case of any abnormality is detected
How a level 2 ultrasound is done
First, the important thing is you need not to be the empty stomach. You may need to drink some water before your exam so you’ll have a full bladder, which makes it easier to take ultrasound images.
You’ll lie on an exam table with your abdomen exposed, and a sonographer will apply gel and then move a transducer over your abdomen. The detailed level 2 scan can take 30 to 45 minutes depending upon the position of your baby at the time of examination, so be patient for best results. You may be told to wait for sometime and take a stroll or drink some juice if the position of the baby is not allowing the doctor to see some parts of the fetus.
During the scan, your doctor may show you the heartbeat, hands, feet, spine, and face of your baby. You may even catch sight of your baby yawning, sucking a thumb, waving the hand, kicking etc.
What is the significance of the results of this scan
In very few cases severe structural abnormalities can be detected at this stage like anencephaly, the fetus with multiple structural abnormalities, skeletal dysplasias, absent liquor with abnormalities kidneys etc seen. In these cases and carrying the pregnancy further is of no use and termination of pregnancy is the only option.
Detection of such abnormalities at this early stage helps in timely and safe medical termination of pregnancy ( which is not allowed in India once the fetus crosses 20 weeks)
In many cases, soft markers are detected ( i.e few markers which indicate the risk of having any chromosomal abnormality) like choroid plexus cysts, hypoplastic nasal bone, echogenic focus in heart, fetal ventriculomegaly etc.
Very few babies showing soft markers end up having an abnormality. If any of these markers are seen on the USG scan, your practitioner will let you know whether any follow-up testing is necessary (like amniocentesis, chorionic venous sampling, NIPT etc).
It is not necessary that every abnormality detected in the anomaly scan will result in the termination of the pregnancy. Some abnormalities can also be treated whereas some other defects are so minute that they hardly affect the birth and growth of the baby.