Internal scan (TVS, transvaginal ultrasound)

What it is

Because the probe is closer to the womb and ovaries, the pictures are clearer than a scan over the tummy. It is often used in early pregnancy and for gynaecology problems. On our rate list it is done with colour Doppler.

How it's done

You lie on your back with your knees bent. The doctor covers the thin probe with a clean cover and gel and places it gently inside the vagina. You may feel some pressure, but it is not usually painful. Female assistants and attendants are present at the centre.

Why doctors ask for it

• Early pregnancy: to confirm the pregnancy, check it is in the womb, and see the heartbeat
• Pain or bleeding in early pregnancy, including checking for an ectopic pregnancy
• Checking the ovaries, for example for cysts
• Checking the lining of the womb, or irregular or heavy periods
• Fertility checks and follicle tracking