An ultrasound scan, or USG scan, is one of the most crucial diagnostic procedures performed throughout the pregnancy. This imaging technique employs high-frequency sound waves instead of harmful radiation to create images of the womb, fetus, placenta, and amniotic fluid in real time. A USG scan enables the obstetrician to track the development of the fetus, ensure its proper growth throughout the pregnancy, and spot possible complications.
Types of Pregnancy Ultrasound Scans
There are usually four different types of ultrasounds performed during pregnancy. Depending on the trimester, the doctor may prescribe several scans:
- Transabdominal Ultrasound: The most common type of scan performed throughout the pregnancy; a specialist moves a special instrument called a transducer with a gel on the patient’s belly to obtain images;
- Transvaginal Scan (TVS): Often done during the first trimester to see the womb and detect complications; the transducer is placed in the vagina after being covered with a disposable sheath;
- 3D/4D Ultrasound: An updated version of the standard scan that provides three-dimensional images or video streams (in case of 4D);
- Fetal Doppler: A special scan that monitors the blood flow in the umbilical cord, placenta, and fetus to make sure that the fetus is getting enough oxygen and nutrients.
Pregnancy Scans Dates and Objectives
The doctor usually schedules several scans during the pregnancy to monitor the health condition and growth of the fetus. The following procedures are the most common:
- Viability Scan: Performed between the 6th and 9th week to confirm whether the fetus is viable; it also determines the due date of the birth, the number of conceptions (single or multiple), and the heart rate of the embryo.
- NT (Nuchal Translucency) Scan: Done between the 11th and 13th week to estimate the chances of the baby having Down Syndrome by measuring fluid at the back of the baby’s neck.
- Anomaly Scan: The most detailed procedure done between the 18th and 22nd week to spot any irregularities in the fetus’s body structure, such as heart defects, kidney issues, spine deformities, etc.
- Growth and Wellbeing Scan: Performed between the 28th and 32nd week to assess the fetus’s weight and growth rate, check the position of the womb and placenta, and estimate blood flow with the help of the Doppler.
Preparation for an Ultrasound Scan
Since an ultrasound is generally a harmless procedure, the preparation is minimal. However, to get the most accurate results, a pregnant woman should:
- Drink plenty of water to fill the bladder if the procedure is scheduled before the 12th week; a full bladder acts as an amplifier that helps to get clear images.
- Wear clothes with a two-piece or stretchy skirt to allow free access to the womb during the scan.
- Talk to your specialist about the preparation guidelines, especially if you are advised to have a transvaginal scan, which requires an empty bladder.
An ultrasound scan is a vital procedure during pregnancy that helps ob/gyn to monitor the health and growth of the fetus and spot possible complications. Knowing the purpose and preparation guidelines for each scan can help future mothers know what to expect during their appointment.
