MODEL RELEASED. Pregnancy ultrasound. Pregnant woman putting her hand over her mouth in excitment at seeing her ultrasound scan. The sonographer is holding print-outs of the scan for the woman to keep. The sonographer used a transducer (not seen) to scan the woman's abdomen. The transducer emits high- frequency sound waves and detects the reflected echoes. The results are used to build an image of the developing foetus in the womb, which is displayed on a monitor. This is a safe, non- invasive procedure used routinely to assess the growth and health of the developing foetus.