The objective of obstetric ultrasound is to provide a safe, non-invasive, and accurate method to clinically evaluate the pregnant uterus and fetus. The evaluation starts right from the confirmation of a viable (alive) pregnancy to throughout the woman’s pregnancy.
Ultrasound imaging is a kind of radiological assessment. It is also called ultrasound scan or ultrasound sonography (USG) or sonography. It consists of a small probe called a transducer that is placed directly over the skin.
A gel is applied over the skin before placing the transducer. High-frequency sound waves generated in the device travel from the transducer through the gel into the body. Sound is absorbed by the tissues and reflected to the transducer. The sound waves are converted to electrical impulses that are interpreted as black and white images.
Why is obstetrics ultrasound performed?
Obstetric ultrasound is performed every three to four weeks to monitor the fetus and pregnant uterus throughout pregnancy.
First-trimester obstetric ultrasound
An ultrasound is performed initially to confirm a viable pregnancy. It may be performed either trans-abdominal (the transducer is placed over the abdomen) or trans-vaginally (the transducer is narrow and placed in the vagina). Sometimes, both may be done simultaneously.
It is ideally performed before 13-14 weeks of pregnancy. A first trimester ultrasound examination can help diagnose a miscarriage early and the presence of multifetal gestations (multiple fetuses such twins or triplets). A first semester ultrasound also helps to evaluate the mother’s reproductive system to detect anatomical abnormalities and pathologies.
Second- and third-trimester ultrasounds help to assess fetal growth and anatomy. An obstetric ultrasound examination may also include evaluation of the fetal position, amniotic fluid volume around the fetus in the uterus, location of the placenta, fetus cardiac activity, the fetal spine and fetal anomalies.
If fetal anomalies are detected between 18 and 20 weeks of pregnancy, termination of pregnancy may still be an option. Monitoring the fetus with the help of ultrasound helps to monitor fetal health, determine the mode of delivery, and calculate the estimated fetal weight and amniotic fluid. Fetal growth evaluations are typically performed every three to four weeks.
Hope you found this information helpful. Good luck with your pregnancy!!!
