Twenty-eight of the municipalities with the nation's top 30 average birthrates are in the island areas of Kyushu and Okinawa Prefecture.
The birthrate between 1998 and 2002 in urban areas such as Tokyo was meanwhile relatively low, according to a report on population trends released Friday by the Health, Labor and Welfare Ministry.
Ministry officials theorized that communities in the island areas are more closely knit and offer an environment that provides child-rearing support. They said there might be more women in urban areas who do not marry.
The ministry report says the national average was 1.36 births per woman.