ABSTRACT
A small array mounted on a long probe and placed in the vagina is commonly used for first trimester scanning (Figure 6.1a). Transvaginal ultrasound is also useful for examining the cervix later in pregnancy and for identifying the lower edge of the placenta. Generally, after 12 weeks, an abdominal transducer, which is a flat probe with a much wider array, is used (Figure 6.1b).
