Other causes include blood clots (3%) and pre-existing conditions (28%). Maternal mortality caused by severe bleeding and infections are mostly after childbirth. Indirect causes are malaria, anaemia, HIV/AIDS, and cardiovascular disease, all of which may complicate pregnancy or be aggravated by it. Risk factors associated with increased maternal death include the age of the mother, obesity before becoming pregnant, other pre-existing chronic medical conditions, and cesarean delivery. Pregnancy-related deaths between 2011 and 2014 in the United States have been shown to have major contributions from non-communicable diseases and conditions, and the following are some of the more common causes related to maternal death: cardiovascular diseases (15.2%.), non-cardiovascular diseases (14.7%), infection or sepsis (12.8%), hemorrhage (11.5%), cardiomyopathy (10.3%), thrombotic pulmonary embolism (9.1%), cerebrovascular accidents (7.4%), hypertensive disorders of pregnancy (6.8%), amniotic fluid embolism (5.5%), and anesthesia complications (0.3%). 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. Structural support and family support influences maternal outcomes. Furthermore, social disadvantage and social isolation adversely affects maternal health which can lead to increases in maternal death. Additionally, lack of access to skilled medical care during childbirth, the travel distance to the nearest clinic to receive proper care, number of prior births, barriers to accessing prenatal medical care and poor infrastructure all increase maternal deaths.