According to a 2004 WHO publication, sociodemographic factors such as age, access to resources and income level are significant indicators of maternal outcomes. Young mothers face higher risks of complications and death during pregnancy than older mothers, especially adolescents aged 15 years or younger. Adolescents have higher risks for postpartum hemorrhage, puerperal endometritis, operative vaginal delivery, episiotomy, low birth weight, preterm delivery, and small-for-gestational-age infants, all of which can lead to maternal death. The leading cause of death for girls at the age of 15 in developing countries is complication through pregnancy and childbirth. They have more pregnancies, on average, than women in developed countries and it has been shown that 1 in 180 fifteen-year-old girls in developing countries who become pregnant will die due to complications during pregnancy or childbirth. This is compared to women in developed countries, where the likelihood is 1 in 4900 live births. However, in the United States, as many women of older age continue to have children, trends have seen the maternal mortality rate to rise in some states, especially among women over 40 years old.