Adolescentpregnancy is a social problem that has been increasing due to several factors are the lack of objective information about sexuality, deficiencies in the use and management of different contraceptive methods, the beginning of sexual life at younger ages, addictions, family problems, among others. Objective: to describe the factors that influence pregnancies in adolescents under 18 years of old in the General Hospital Dr. Donato G. Alarcón. Methodology: Type of study: descriptive, quantitative and cross-sectional population pregnant adolescents under 18 years, the convenience sample for a period of time were selected 30 adolescents who attended consultation for two weeks at the hospital Donato G. Alarcón, the dependent variable was pregnancy in adolescents and the processing and analysis of the information was done through the SPSS program version 20 and the descriptive statistics were applied. Results: The factors that influence adolescent pregnancy are 65% more than half the inappropriate use of contraceptives, the lack of confidence in the family environment and ignorance about reproduction and sexuality in the same percentage of 15%. The age that predominated among adolescents was 17 years with 60%, followed by 18 years with 25% and 14 to 16 with 15%. Conclusions: The risk factors that influence adolescent pregnancy are the inadequate use of contraceptives, the lack of confidence in the family environment and the ignorance about reproduction and sexuality in adolescents between 14 and 17 years old, since during this period most of them start their active sexual life affecting their physical, emotional, social and professional development.