MODEL RELEASED. Pregnancy ultrasound. Pregnant woman having her swollen abdomen scanned by an ultrasound transducer (in hand). The transducer emits high-frequency sound waves and detects the reflected echoes. The results are used to build an image of the unborn child in the womb (seen on the screen). This safe, non-invasive procedure is used routinely in pregnancy to assess the growth and health of the developing foetus, and to detect any abnormalities. This is a standard anomaly scan, carried out when the mother is 20 weeks pregnant. The detection of a serious anomaly at this stage (halfway through pregnancy), allows surgery or a termination to be considered.