FTSE 250 retailer Mothercare has seen total sales rise but the performance of the UK operation continues to disappoint.What the firm calls "group network sales" or the combination of international and domestic trading was up 6.7% although this includes franchisees and joint ventures.The company is keen to emphasise its growing international presence in Eastern Europe, the Middle East and Asia-Pacific. Its reach is extensive with 1289 stores in 55 countries. However, the UK stores saw sales drop by 1.8% in the first quarter and like-for-like sales (which compares the performance of stores that have been trading from the same building for at least a year) was down a worrying 4.3%.Responding to the results Mothercare's chairman Ian Peacock described the UK trading environment as "difficult and competitive".Investors greeted the announcement with a shrug, with Mothercare's share price down 1% in early trading at 406.30pBS