The policy depends on virtually universal access to contraception and abortion. A total of 87 percent of all married women use contraception; this statistic compares with about one third in most developing countries. There is heavy reliance on long-term contraception, with intrauterine devices and sterilizations together accounting for more than 90 percent of contraceptive methods used since the mid-1980s. The number of sterilizations has declined since the peak in the early 1990s. For the majority of women, no choice in contraception is offered; 80 percent of women in a recent large study said they had no choice and just accepted the method recommended by the family-planning worker. The use of these long-term methods keeps abortion rates relatively low, with 25 percent of women of reproductive age having had at least one abortion, as compared with 43 percent in the United States. The main reasons given for abortion are contraceptive failure and a lack of government approval for the pregnancy under the one-child policy. Women who proceed with an unapproved pregnancy are known to be reluctant to use antenatal and obstetric services because they fear they will face pressure to have an abortion or fines for violating the one-child policy. Many deliveries of babies that have not been officially sanctioned occur at home without trained personnel, a practice that is associated with the risk of maternal or neonatal mortality. A study carried out in rural Sichuan province in 1990 reported a doubling of maternal deaths for unapproved pregnancies as compared with those receiving government sanction.