Introduction: Teenage pregnancies have serious consequences for the health of mothers and their children. The aim of this work was to study the circumstances of the onset of teenage pregnancy. Methodology: This was a cross-sectional and descriptive study, which took place from July 1st to 31st, 2019 at the Peripheral Care Unit (USP) of Gbodjomé in Togo. Results: A total of 100 adolescent girls were interviewed (12.6%). The average age of adolescent girls was 17.2 years (12 - 19 years). Adolescent girls were predominantly in primary school (42.0%) and single status (58.0%). Forty-two decimal zero percent of adolescent girls (42.0%) were living with their partners. In 5.0% of cases, adolescent girls were victims of sexual harassment. The pregnancy was the result of rape in 10.0% of cases. Ten decimal zero percent of adolescent girls (10.0%) had more than one sexual partner. Nearly half of the respondents (49.0%) knew at least one method of contraception, but only 8.0% used it. Financial help from the partner (57.0%) was the leading cause of sex. Conclusion: Teenage pregnancies have a negative impact on both the young mother and the unborn child. The ideal would be to make schooling for girls free, from primary school to the A-level.