Very young adolescents are more likely to experience complications during pregnancy and childbirth than adult women and are at greater risk of pregnancy-related death. The infants of adolescent mothers are at higher risk of mortality and morbidity. The adolescent fertility rate (births per 1000 women aged 15–19 years) was highest in the WHO African Region (117 per 1000) and in low-income countries (115 per 1000) compared with a global average of 49 per 1000 for the reference year 2009. In the WHO African Region, fertility is high at all ages and adolescent pregnancies are common. Adolescent fertility is declining in many countries but at a far slower rate than adult fertility.