'Everyone in my family has C-sections': increased likelihood of caesarean birth in family lineages in the United States.

Caesarean birth has multiple, interrelated, and often mutually reinforcing bio-social etiologies. Evolutionary consequences of caesarean are uncertain. The goal of this study is to determine if caesarean births are more likely within family lineages by connecting and comparing lifetime birth experience (caesarean, vaginal) of individual women and generations of their families. A secondary goal is to identify potential parity differences between birth modes. Qualitative and quantitative methods were used to evaluate women's birth narratives of their own births and births to their maternal relatives: grandmothers, mothers, sisters, daughters. Participant data was analysed by birth year cohort and by familial generation (Grandmother, Mother, Index, and Daughter). 107 women participated in the study. Parous daughters of women who experienced any caesarean were more likely to experience caesarean than were daughters of women experiencing all vaginal birth ( = .0002; relative risk 2.1 [1.53-2.88]). Prevalence of any caesarean per mother is higher than the per-birth caesarean rate (44/107, 41.12% versus 71/229, 31.00%;  = .03). Parity was higher for women experiencing all vaginal births than all caesarean (2.14 versus 1.79;  = .03), yet highest for those experiencing any caesarean (2.75;  = .01). Caesarean for any indication is more common among daughters of mothers who themselves experienced any caesarean than those who experienced all vaginal births. Individual lifetime caesarean experience is more prevalent than commonly construed based on caesarean per live birth rate. Clustering of cesarean within families suggests that operative birth is altering our bio-social selves in potentially heritable ways.