Why do you need Detail/Anomaly Scan?
It is a routine practice for pregnant women to have detail or anomaly scan at 18-20 weeks of gestation. Anomaly scan is important as it is the best chance of detecting some abnormalities that can have a profound impact on the health of the mother and the baby. There are a number of aspects of pregnancy that can be assessed during this scan.
- The Anatomy or Structure of baby
The sonographer will have a routine look at the baby’s head and brain, face, heart, umbilical cord insertion, spine, stomach, kidneys, bladder, spin, hands and the feet.
- Baby measurements
During the anomaly scan, sonographer will also measure – Biparietal diameter and head circumference of the baby’s head, abdominal circumference of the baby, femur length of the baby’s leg, humerus length of the baby’s arm and the binocular distance between the baby’s eyes. Each and every measurement is compared with the standard reference range. Each individual baby has its own features and is often similar to the parents. Measurements that are outside the normal range are not significant, if there is a minimal difference.
- Heart rate and rhythm of baby
The heartbeat of a baby may vary and is usually not the same as in adults. Most of the babies have a heartbeat rate of 120-200 beats per minute.
- Position of placenta
The position of placenta with relation of the cervix is also observed. If the placenta is very close to the cervix, then it is termed as low-lying placenta. As uterus grows big during the third trimester of pregnancy, it pulls the placenta away from the cervix. The length of cervix is also determined during second trimester.
- Amount of amniotic fluid
The volume of amniotic fluid is accessed subjectively, rather than being measured precisely.