Women often worry about how their ultrasound scan will be performed and whether to arrive for their appointment with a full or empty bladder. Early pregnancy or general gynecology scans can be performed either trans-abdominally (tummy) or trans-vaginally (internal). Both use ultrasound (sound waves) in the same way but approach the area they are looking at from a different angle. Both methods are completely safe for pregnant and non-pregnant women.
A trans-abdominal scan requires a full bladder as it pushes the uterus higher in the pelvis. This allows the transducer to pass the ultrasound waves through the bladder and see the uterus and baby more clearly. In most cases this type of scan is suitable for women over 8 weeks pregnant. In women with a BMI in normal range, a baby may be seen earlier. Women with a higher BMI may see less clear images.
If a pregnancy is less than 8 weeks, a vaginal ultrasound may be needed for clearer images. The bladder should be empty allowing the uterus to remain lower in the pelvis and closer to the vaginal probe. An explanation should always be provided and verbal consent obtained. The probe is covered and only inserted about 3cm into the vagina. The sonographer will always ensure privacy and dignity is maintained not only during the scan but when getting ready. This type of scan is not painful but can feel a bit odd. It is perfectly safe, will not cause a problem for the baby or cause bleeding to happen. This can be the best way to see a tiny baby, but also the womb lining or ovaries for women having fertility treatment.
Women who have had both types of scan often say how much easier it is having an internal scan, and not having to have someone pressing on their very full bladder! However remember you are in control of how your scan takes place and can opt to be scanned either way.