Worried that Shanghai's growing numbers of migrant workers will trigger a population explosion, the city Government is urging birth control workers to better monitor and educate the group. Rural migrants have long flocked to the city to look for jobs in construction, housekeeping and other sectors. The move has picked up over the past decade as the Government pours funds into building and as the city's rising upper and middle classes require more service-sector workers. Despite Shanghai's low birth rate compared with other Chinese cities, the local Government is sounding an alarm that a baby boom could reverse much of the progress made over the past 10 years. Alternative measures to control migration into Shanghai, and the prolific birth rate of migrants, 'are now being researched by many universities, and the results of our studies will later be examined by the Government', said Chen Jiahua, a researcher at Fudan University's Population Institute. Shanghai Communist Party secretary Huang Ju told experts and government workers meeting this week to better manage population growth. Population workers were told that, 'due to poverty and poor education, the unplanned birth rate among the migrant population is 15 times that of the city's permanent residents', the Shanghai Daily reported. Zhou Jianping, director of the Shanghai Population and Family Planning Committee, said during the population conference that an influx of migrants was placing pressure on the city's infrastructure. He said 'strict policies on birth control, migrant supervision and population management were key to conquering these problems'. 'Though many [migrant workers] take on tough jobs and contribute to social development, they also create a burden on birth control,' he said. The Shanghai Daily reported that the city Government was likely to 'create a system to track registered migrants in every neighbourhood in Shanghai, offer birth control education to all migrants and provide contraceptives and medical advice for them'. Government statistics indicate that at the end of last year there were three million registered migrants plus 13.3 million permanent residents in Shanghai. Professor Chen said: 'No one is sure how many unregistered migrants there are in Shanghai.' He said the Government had ordered feasibility studies on various methods to control the birthrate because 'Shanghai is already a megacity and has a huge population'. The Shanghai Government is expecting a baby boom to begin in about 2005. This is partly fuelled by the migrants and partly by a quirk in the party's population policies. The sole children produced under the first wave of China's one-couple, one-child rule, if married to another sole child, are allowed to have two children.