Intergenerational abortion tendency between mothers and teenage daughters: a population-based cohort study

Background — A teenage woman’s sexual health practices may be influenced by her mother’s experience. We evaluated whether there is an intergenerational tendency for induced abortion (IA) between a mother and her teenage daughter.

Methods — A retrospective population-based cohort study was conducted in Ontario among 431,623 daughters born in 1992-1999. Daughters were evaluated for IA from ages 12-19 years. A mother’s history of IA was assessed in the period from -4 years before her daughter’s birth, up to +12 years thereafter, when her daughter turned age 12 years. Cox proportional hazard models were used to estimate a daughter’s risk of having an IA in relation to her history of IA. HRs were adjusted for maternal age and world region of origin, mental or physical health problems in the daughter,mother-daughter cohabitation, and neighborhood-level teen IA rate, rural/urban residence and income quintile.

Results — The cumulative probability of teenage IA was 10.1% (95% CI 9.8-10.4) among daughters whose mother had an IA, and 4.2% (95% CI 4.1-4.3) among daughters whose mother had no IA – an adjusted HR of 1.94(95% CI 1.86-2.01). The adjusted HR of a daughter having a teenage IA was 1.77 (95% CI 1.69- 1.85) with one, 2.04 (95% CI 1.91-2.18) with two, 2.39 (95% CI 2.19-2.62) with three, and 2.54 (95% CI 2.33-2.77)with ≥ 4 maternal IA, relative to none.

Interpretation — The risk of having a teenage IA is higher among daughters whose mother had an IA. Future research should explore the mechanisms for intergenerational IA.