Estradiol trajectories and early pregnancy loss: a retrospective study

To investigate the association between early pregnancy estradiol (E2) trajectory patterns and the risk of early miscarriage in women with natural conception.

This retrospective study included 527 women aged 18-45 years with natural conception and at least three E2 measurements within the first 12 gestational weeks, from March 2023 to August 2024. Group-based trajectory modeling identified four distinct E2 trajectories. Demographic and clinical data were extracted from medical records, and pregnancy outcomes were obtained through follow-up. Multivariate logistic regression and subgroup analyses were performed to evaluate the association between E2 trajectories and early miscarriage.

Among the four identified E2 trajectories, women in Trajectory 3 ("High Level with Steady Increase") showed a significantly reduced risk of early miscarriage compared to those in Trajectory 2 ("Low Level with Slow Increase") (adjusted OR = 0.24, 95% CI: 0.12-0.46, p < 0.001). Subgroup analyses stratified by age and number of previous miscarriages confirmed the robustness of this association, while no significant associations were found for the other trajectories. The highest miscarriage rate (42.03%) and lowest baseline E2 level (300.29 ± 194.23) were observed in Trajectory 2.

A steadily increasing high estradiol trajectory in early pregnancy is associated with a lower risk of early miscarriage, highlighting the potential value of E2 monitoring for early pregnancy risk assessment.