Association of uterine fibroids with adverse pregnancy outcomes: a retrospective cohort study

To investigate the independent association between uterine fibroids and adverse pregnancy outcomes, and to explore the influence of fibroid characteristics, including type and location, on these risks. This retrospective cohort study was conducted at a single tertiary hospital in Beijing, China, including all singleton deliveries between January 2022 and April 2023. A total of 2,118 pregnant women were enrolled, comprising 317 with uterine fibroids (fibroid group) and 1,801 without (control group). Maternal baseline characteristics, obstetric outcomes, and perinatal data were extracted from electronic medical records. Multivariable logistic regression analyses were performed to determine if uterine fibroids were independent risk factors for cesarean section, postpartum hemorrhage (PPH, ≥ 500 mL), and fetal malpresentation, after adjusting for potential confounders. Subgroup analyses were conducted to evaluate risks associated with fibroid size, number, type, and location. Women in the fibroid group were significantly older (34.4 ± 3.7 vs. 32.1 ± 4.0 years, P < 0.001) and had higher rates of gestational diabetes mellitus, hypertensive disorders, severe preeclampsia, placenta previa, placental accreta spectrum, and anemia (all P < 0.05). In univariate analysis, the fibroid group had significantly higher rates of cesarean Sect. (54.9% vs. 42.0%, P < 0.001), PPH (28.1% vs. 7.3%, P < 0.001), and fetal malpresentation (5.0% vs. 2.6%, P = 0.018). After a more comprehensive adjustment for confounders, including placental disorders, uterine fibroids remained an independent risk factor for cesarean section (adjusted odds ratio [aOR] 1.52, 95% CI: 1.18–1.95), PPH (aOR 4.98, 95% CI: 3.69–6.72), and fetal malpresentation (aOR 1.99, 95% CI: 1.10–3.60). Subgroup analysis revealed that submucosal type, lower uterine segment location, large fibroids (≥ 5 cm), and multiple fibroids were associated with a significantly increased risk of adverse outcomes. The presence of uterine fibroids during pregnancy is a strong and independent risk factor for cesarean section, postpartum hemorrhage, and fetal malpresentation. Specific fibroid characteristics, such as submucosal type, lower segment location, large size, and multiplicity, further amplify these risks. These findings underscore the need for heightened antenatal surveillance and meticulous delivery planning for this high-risk population.