Most women only need two scans in each pregnancy, but if your medical team are even the slightest bit concerned, you’ll be given further scans and tests along the way. This is because not all conditions can be pinpointed at the 20-week scan, especially if they do not have a physical appearance. Some such as spina bifida, a defect of the spinal cord, can be clearly seen, though heart conditions may be more difficult to see for example. For some conditions, such as cleft lip or club feet, parents can plan for their baby having corrective surgery soon after birth.