The role of ultrasound in obstetrics

Ultrasound in obstetrics is like a doctor's stethoscope. To date, despite the benefits and importance that have been confirmed, there are no studies showing harmful effects of ultrasound...
Ultrasound during pregnancy is very important, in order to determine:
» The number of fetuses, the nature of the placenta if it is multiple pregnancies (need to determine the status of the placenta or separate placental fetuses, this is valuable in predicting the risk for fetal development)
» Fetal activity
» Is the position of the fetus in the uterus or ectopic
» Fetal biometric index (Fetal size)
» Fetal position
» Placement and maturity of the placenta
» Assessment of amniotic fluid
» Assess fetal morphological abnormalities (3D, 4D ultrasound)
» Assess placental perfusion (Doppler ultrasound)
During the first 3 months of pregnancy, 2D ultrasound will help the obstetrician calculate age The difference between pregnancy and due date is only 3 days. Through ultrasound, the doctor knows how many fetuses, identical or fraternal, live or stopped developing, especially helping to determine whether the pregnancy is inside or outside the uterus. In addition, at 11 - 13 weeks and 6 days, we need to perform an ultrasound to measure the light on the back of the baby's nape (NT ultrasound), which is an early indicator indicating that the fetus is at risk of fetal syndrome. Down or not. The time of 20 - 22 weeks is an extremely important time for the investigation of fetal malformations by 3-dimensional (3D) ultrasound and 4-dimensional (4D) ultrasound. At 30 - 32 weeks of pregnancy, another ultrasound is required, this ultrasound helps detect some morphological abnormalities that occur late such as abnormalities in the arteries, heart and a structural area of ​​the brain. In addition, ultrasound at 30 - 32 weeks also helps to recognize slow growth in the uterus.

So far there have been no studies showing harmful effects of ultrasound .
Thus, ultrasound must be done at least 3 times for normal pregnancies (11 - 13 weeks, 20 - 22 weeks and 30 - 32 weeks) and there is no maximum limit on the number of ultrasounds. . To date, there have been no studies showing harmful effects of ultrasound. Therefore, fetal ultrasound is still considered very safe and does not appear to present a significant risk. Although no long-term harmful effects of prenatal ultrasound on the fetus have been found, experts still recommend that antenatal ultrasound should not be used for non-medical purposes. For example: ultrasound just to know if it's a boy or a girl, or to see what the baby's shape is like...
In addition to the above routine ultrasounds, during antenatal care, doctors will decide whether to have a baby. Indicate ultrasound or not when there are markers. For example, when measuring the height of the uterus, the index does not increase with gestational age, the doctor thinks about the possibility of fetal growth retardation, needs to survey the biometric index, survey the amount of amniotic fluid. 2D sonogram; or further, if there is a need to investigate the status of uterine vascularity, the status of placental perfusion through the umbilical artery, the middle cerebral artery of the fetus (in cases of suspected intrauterine growth retardation). , pregnant women with pre-eclampsia, gestational hypertension, gestational diabetes, ...) will need color Doppler ultrasound tools in addition to the above periodic ultrasounds. Therefore, there will not be a universal formula for all mothers.
When there are concerns and questions, mothers need to talk to their doctor for advice.

Ths. Bs. Nguyen Thi Thuy Dieu
Department of Obstetrics and Gynecology
Vinmec International General Hospital