Longitudinal Trajectories of Childbirth Intention Across Pregnancy and Their Association with Actual Mode of Delivery: A Multicenter Prospective Cohort Study in Southwest China

Abstract Objectives Cesarean section (CS) rates in China remain high, whereas an explicit antenatal intention for CS appears uncommon. Most evidence on childbirth intention derives from single-time-point surveys; how intention evolves across pregnancy, and whether its longitudinal trajectory relates to the actual mode of delivery, remains unclear. Methods In a multicenter prospective cohort established in four maternal health facilities in Chongqing, China (2016–2019), 1591 women with singleton pregnancies were enrolled at ≤ 14 gestational weeks; childbirth intention (undecided/vaginal/cesarean) was measured in the first, second and third trimesters, and delivery outcomes were abstracted from medical records. Latent class growth analysis (LCGA) and a three-state Markov transition model were applied to the 1006 women with complete three-wave data. Results At the group level, intention remained stable (all pairwise Wilcoxon p > 0.05). LCGA identified three trajectory classes: intention clarifying (42.9%), moving from undecided toward a vaginal intention; stable vaginal intention (52.1%); and CS-intention reversal (5.0%), converting from an initial cesarean intention toward a vaginal intention. Vaginal intention was the most stable state (early-to-late retention 68.3%) and cesarean intention the least stable (24.5%). Among 967 women with linked outcomes, CS rates differed markedly across classes—31.8% (stable vaginal), 40.7% (clarifying) and 58.3% (CS-intention reversal) (Cramér's V = 0.135)—and trajectories discriminated the outcome better than a single late-pregnancy measurement (V = 0.091). Overall, 33.2% of women with a late-pregnancy vaginal intention delivered by CS, and 91.9% of cesarean deliveries occurred in women without a cesarean intention. Conclusions Group-level stability conceals heterogeneous individual trajectories of childbirth intention. Cesarean intention is highly plastic, whereas converting it does not necessarily avert cesarean delivery. These findings carry direct implications for obstetric clinical practice and prenatal counseling: intention-focused antenatal education should start early—ideally before the second trimester, when the clarifying trajectory is most active—be coupled with intrapartum and system-level strategies, and be embedded in risk-stratified obstetric surveillance, so that longitudinal intention monitoring can contribute to reducing non-medically indicated cesarean sections.