Objective — To estimate the intergenerational association in teenage pregnancy, and whether there is a coupling tendency between a mother and daughter in how their teen pregnancies end, such as a termination of pregnancy (TOP) versus a live birth.
Design — Population‐based cohort study.
Setting — Ontario, Canada.
Population — A total of 15 097 mothers and their 16 177 daughters.
Methods — Generalised estimating equations generated adjusted odds ratios (aOR) of a daughter experiencing a teen pregnancy in relation to the number of teen pregnancies her mother had. Multinomial logistic regression estimated the odds that a teen pregnancy ended with TOP among both mother and daughter. All models were adjusted for maternal age and world region of origin, the daughter's socio-demographic characteristics and comorbidities, mother-daughter cohabitation, and neighbourhood-level teen pregnancy rate.
Main Outcome Measures — Teen pregnancy in the daughter, between ages 15 and 19 years, and also the nature of the daughter's teen pregnancy, categorised as (1) no teen pregnancy, (2) at least one teen pregnancy, all exclusively ending with a live birth, and (3) at least one teen pregnancy, with at least one teen pregnancy ending with a TOP.
Results — The proportion of daughters having a teen pregnancy among those whose mother had zero, one, two, or at least three teen pregnancies was 16.3, 24.9, 33.5 and 36.3%, respectively. The aOR of a daughter having a teen pregnancy was 1.42 (95% CI 1.25-1.61) if her mother had one, 1.97 (95% CI 1.71-2.26) if she had two, and 2.17 (95% CI 1.84-2.56) if her mother had three or more teen pregnancies, relative to none. If a mother had at least one teen pregnancy ending with TOP, then her daughter had an aOR of 2.12 (95% CI 1.76-2.56) for having a teen pregnancy also ending with TOP; whereas, if a mother had at least one teen pregnancy, all ending with a live birth, then her daughter had an aOR of 1.73 (95% CI 1.46-2.05) for that same outcome.
Conclusion — There is a strong intergenerational occurrence of teenage pregnancy between a mother and daughter, including a coupling tendency in how the pregnancy ends.