US DATING TVS SCAN

The first few weeks of pregnancy are filled with excitement, anticipation, and many questions. One of the most important early milestones is the Dating Scan / TVS, often the very first ultrasound you will have. This scan provides crucial information and profound reassurance as you begin your journey to parenthood.

At Cadabams Diagnostics, we understand the significance of this moment. A dating scan has several primary goals: it confirms that your pregnancy is located in the correct place (the uterus), determines the precise gestational age, and, most excitingly, confirms the presence of a fetal heartbeat. It is a safe, non-invasive procedure, most often performed using a transvaginal probe (TVS) to provide the clearest and most detailed images possible in early pregnancy.

What is a Dating Scan?

A Dating Scan / TVS is a diagnostic imaging test that uses high-frequency sound waves (ultrasound) to create real-time images of your pelvic organs and the developing pregnancy. It does not use any radiation and is completely safe for both you and your baby.

In the first trimester, a transvaginal ultrasound for pregnancy is the preferred method. This is because the probe can be placed closer to the uterus, providing a much clearer and more detailed view of the tiny, developing fetus than a scan performed over the abdomen. This clarity is essential for making accurate measurements and assessments.

Types of Dating Scan

There are two primary methods for performing a dating scan, with one being the standard for early pregnancy.

• Transvaginal Scan (TVS): This is the gold standard for an early pregnancy ultrasound. A slender, specially designed and lubricated probe is gently inserted into the vagina. Its proximity to the uterus allows for high-resolution images, making it superior for detecting the earliest signs of development.
• Transabdominal Scan: This is the method many people picture when they think of an ultrasound, where a probe is moved over the skin of the lower abdomen. While used later in pregnancy, it is less common for dating scans because the uterus is still very small and located deep within the pelvis, often resulting in less clear images.

Your sonographer will be looking for several key markers to assess the health and progress of your pregnancy. These include:

• Gestational Sac: The presence, location (inside the uterus), and size of the fluid-filled sac that encloses the embryo.
• Yolk Sac & Fetal Pole: The identification of these structures is a positive sign of early development. The yolk sac provides nourishment until the placenta takes over, and the fetal pole is the first visible sign of the developing embryo.
• Crown-Rump Length (CRL): This is the single most important measurement taken during a dating scan. It measures the fetus from the top of its head to the bottom of its torso. This measurement is used to accurately determine the gestational age and calculate your Estimated Due Date (EDD).
• Fetal Heart Rate (FHR): The presence of a heartbeat and its rate (measured in beats per minute) are measured to confirm viability.
• Number of Fetuses: The scan will confirm if you are carrying a single baby, twins, or other multiples.
• Uterus and Ovaries: The surrounding structures, including your uterus and ovaries, are assessed for any co-existing conditions, such as fibroids or cysts, that might be relevant to the pregnancy.

This first scan serves several critical purposes that set the stage for your entire pregnancy care plan.

• Confirm Viability: The scan’s primary purpose is to act as a viability scan, confirming that the pregnancy is developing and has a heartbeat.
• Accurate Dating: It precisely calculates the gestational age of the fetus. This is crucial for properly scheduling subsequent tests, like the Nuchal Translucency (NT) scan, and for monitoring fetal growth throughout the pregnancy.
• Rule Out Ectopic Pregnancy: A key safety check is to ensure the gestational sac is located inside the uterus, thereby ruling out a potentially life-threatening ectopic pregnancy where the embryo implants outside the womb (usually in a fallopian tube).
• Investigate Symptoms: If you are experiencing early pregnancy bleeding or cramping, a dating scan can help identify the cause and provide vital information to your doctor.

When and Who Needs to Take a Dating Scan?

• Timing: A dating scan is typically performed between 6 to 10 weeks of pregnancy. This window is ideal for getting the most accurate measurements.
• Who Needs It: This scan is recommended for all pregnant individuals to establish an accurate due date. It is especially vital if you:
  • Have irregular menstrual cycles.
  • Are unsure of the date of your last menstrual period (LMP).
  • Have conceived through assisted reproductive technology (like IVF).
  • Have a history of miscarriage or ectopic pregnancy.
  • Are experiencing early pregnancy symptoms like bleeding or cramping.

Benefits of Taking the Test

The benefits of undergoing a Dating Scan / TVS extend beyond the medical report.

• It provides invaluable peace of mind and reassurance to expectant parents by confirming a viable pregnancy.
• It establishes an accurate, reliable timeline for your pregnancy journey.
• It allows for the early detection and management of potential issues, leading to better outcomes.
• It is an incredible first opportunity to see your baby and hear their heartbeat.

Illnesses Diagnosed with US Dating TVS Scan

While primarily for dating and viability, this early pregnancy ultrasound can also help confirm or rule out several critical conditions:

• Ectopic Pregnancy: Pregnancy located outside the uterus.
• Molar Pregnancy: A rare condition involving an abnormal growth of tissue inside the uterus instead of a viable embryo.
• Missed Miscarriage: A situation where the fetus is no longer viable, but the body has not yet expelled the pregnancy tissue.
• It can also identify other issues that may need monitoring, such as uterine fibroids or large ovarian cysts.

Preparation for your Dating Scan / TVS at Cadabams Diagnostics is simple.

• Bladder: For a Transvaginal Scan (TVS), you will be asked to empty your bladder right before the procedure. A full bladder can obstruct the view, whereas an empty one allows the probe to get closer to the uterus for clearer images.
• Attire: Wear a comfortable, two-piece outfit (like a top and pants or a skirt). This is more convenient as you will only need to remove your lower clothing.
• Doctor's Note: Please bring the referral or prescription from your doctor for the scan.

Pre-requisites

A referral from your gynaecologist or family doctor is typically required for the scan. No fasting or special diet is needed before your appointment.

Best Time to Take the Dating Scan

The optimal window for a Dating Scan / TVS is between 6 and 10 weeks of gestation. Performing the scan within this period provides the most accurate Crown-Rump Length (CRL) measurement for dating the pregnancy.

Eligibility

Anyone who is in their first trimester of pregnancy is eligible for this scan. There are no medical contraindications.

Procedure for Taking a Dating Scan

We strive to make your first trimester scan procedure as comfortable and stress-free as possible.

1. Check-in: You will check in at the reception at Cadabams Diagnostics. You may be asked to change into a medical gown.
2. Preparation: You will be led to the ultrasound room and asked to empty your bladder.
3. Positioning: Our sonographer will ask you to lie down on your back on the examination table, with your knees bent.
4. The Scan: For a TVS, the sonographer will explain the process. A thin, lubricated probe, covered with a sterile, disposable sheath, is gently inserted into the vagina. The sonographer will carefully move the probe to get clear images of your uterus and the pregnancy from different angles. This process is gentle and should not be painful.
5. Duration: The entire appointment, including preparation and the scan itself, usually takes about 20-30 minutes.

Caution Before Taking the Test

• Please inform the sonographer before the scan if you have a known latex allergy, as the probe covers may contain latex. We have non-latex alternatives available.
• Your comfort is our priority. Please communicate with the sonographer if you experience any significant discomfort or pain during the procedure.