Introduction Mexico has in recent years one of the highest rates of caesarean sections in the world and in turn, high rates of adolescent fertility. This study seeks to know the caesarean rate and to identify factors socioeconomic and related to medical practice associated to caesarean section in primiparous mothers under 20 years old in Metropolitan Area of Guadalajara, Mexico.

Methods The study was conducted at various public hospitals randomly selected of different health institutions of the MAG. A cross-sectional study was carried out, collecting data of all <20 years old primiparous mothers that had their delivery at the hospitals included in study during the second half of 2008 (sample size: caesarean section 306, vaginal delivery 462). A logistic regression model was used to estimate ORs with 95% CIs.

Results Almost 40% of total deliveries were by caesarean section. In the multivariate analysis five factors were statistically associated with the caesarean section: labour induction (OR =5.2, CI 2.8 to 9.5), body mass index ≥26 (OR =4.0, CI 1.7 to 9.4), low socioeconomic level (OR =2.9, CI 1.5 to 5.7), birth weight >3.500 g (OR =2.0, CI 1.0 to 4.2) and maternal age 18–19 (OR =3.4, CI 1.6 to 7.1).

Conclusions The cesarean section rate among adolescents is extremely high. Identified factors suggest the necessity of an adequate prenatal care to control those aspects that could lead to a caesarean section, but also the importance of quality care during childbirth to try to reduce the observed rates in the MAG.