Nationwide cohort study reveals rising cesarean rates driven by maternal aging and post-2015 birth cohort effects in South Korea, indicating shifts in modern obstetric practices.
Key Points
To examine how maternal age, calendar period, and maternal birth cohort contribute to the rising rates of cesarean section deliveries.
Analyzed nationwide National Health Insurance claims data from South Korea covering 6,635,390 deliveries among women aged 15–44 years between 2007 and 2024.
Classified delivery mode into cesarean section or vaginal delivery.
Employed hierarchical age–period–cohort cross-classified random-effects models adjusted for parity, insurance type, and hospital facility type, stratified by parity.
Estimated period random effects showed a sustained increase from 2015 onward across deliveries.
Estimated cohort random effects were positive among women born between 1992 and 2002.
The observed age, period, and birth cohort patterns were substantially more pronounced among primiparous women.