Recent pregnancy trends among early adolescent girls in Japan

The paper examines recent time trends, explores potentially influential background factors and discusses prevention strategies of pregnancy among girls under 15 years of age in Japan.

Using Japanese government data, we first analyzed time trends of early adolescence (<15 years of age) abortion, live birth and child sexual abuse from 2003 to 2010. Second, we analyzed ecological correlations of early adolescent pregnancy (abortion, live birth and stillbirth) with pregnancy in other age groups, child sexual abuse, and indicators of juvenile victimization and juvenile delinquency, using prefectural data.

We found that rates of both abortion and live birth in early adolescents have increased since 2005 (annual percent change 5.3% and 2.3%, respectively), despite declining rates in older age groups. The abortion ratio in early adolescence remained the highest among all age groups in Japan. The early adolescent pregnancy rate showed significant correlation with the rates of juvenile victimization of welfare crimes (obscenity, alcohol drinking, smoking and drug use) (Spearman's rank correlation coefficient [rs] = 0.42, P = 0.00) and juvenile delinquency among junior high school students (12-14 years of age) (rs = 0.69, P = 0.00).

The observed rise in rates of abortion, live birth and child sexual abuse among early adolescents along with strong ecological correlations of their pregnancy rate with juvenile victimization and delinquency indicators suggests that epidemiological investigation and public health programs at the individual and community levels are needed to address the complex social roots of these trends and to produce effective improvements in early adolescent reproductive health.