Association between uterine artery embolization for postpartum hemorrhage and second delivery on maternal and offspring outcomes: a nationwide cohort study.

Study question: What are the maternal and neonatal outcomes of second delivery in women who underwent uterine artery embolization (UAE) during their first delivery?

Summary answer: Women who underwent UAE during their first delivery exhibited higher risks of placental problems, preterm births, and postpartum hemorrhage (PPH) in second delivery and the second offspring also showed increased risk of major congenital malformations, admission to the neonatal intensive care units (NICU), necrotizing enterocolitis, intraventricular hemorrhage, and bronchopulmonary dysplasia.

What is known already: UAE is a minimally invasive procedure used as an alternative to hysterectomy for managing severe PPH. However, recent studies have raised concerns about potential obstetric complications, including recurrent PPH, placenta accreta spectrum (PAS), and fetal growth restriction in subsequent delivery following UAE.

Study design size duration: This was a nationwide retrospective cohort study using the Korean National Health Insurance Service (K-NHIS) database, covering 50 million individuals from 2004 to 2020. The cohort included 3 616 923 women with live births between 1 January 2005 and 31 December 2019 with follow-up data extending to 31 December 2020.

Participants/materials setting methods: The study included women who had their first live birth between 2005 and 2019, excluding those who underwent hysterectomy (without UAE = 3 612 389, UAE = 4534). Among them, we selected women who had single gestation secondary delivery (without UAE = 1 694 600, UAE = 1146). Propensity score matching was used to control for confounding factors, resulting in 11 184 women without UAE and 1119 women with UAE for subsequent analysis.

Main results and the role of chance: Women in the UAE group had significantly higher risks of PAS (odds ratio (OR) = 38.91, 95% CI = 18.61-81.34), placenta previa (OR = 6.98, 95% CI = 5.57-8.75), and preterm birth (OR = 2.23, 95% CI = 1.71-2.90) during their second delivery. The risk of recurrent PPH was also significantly higher (OR = 8.94, 95% CI = 7.19-11.12). Their second offspring were more likely to have major congenital malformations (OR = 1.62, 95% CI = 1.25-2.11) and adverse neonatal outcomes, including NICU admissions (OR = 1.83, 95% CI = 1.48-2.25). Long-term outcomes showed a higher risk of attention-deficit/hyperactivity disorder (hazard ratio = 1.64, 95% CI = 1.03-2.63) but were otherwise comparable to those in the without UAE group.

Limitations reasons for caution: Retrospective nature of the study may have introduced exposure and outcome misclassifications, despite the reliability of the K-NHIS database. Unmeasured confounders and selection bias due to only including live births could also have influenced the results.

Wider implications of the findings: Women with a history of UAE require meticulous prenatal care and close monitoring during subsequent deliveries due to increased risks of complications. Counseling and referral to high-risk medical centers may improve outcomes. Further research is needed to understand the mechanisms of complications in both mothers and offspring at sequential delivery, as well as to refine UAE procedures.

Study funding/competing interests: This study supported by Patient-Centered Clinical Research Coordinating Center (PACEN) funded by the Ministry of Health & Welfare, Republic of Korea (HC21C0123). This study was funded by S.-Y.O. The authors of this manuscript declare no relationships with any companies whose products or services may be related to the subject matter of the article.

Trial registration number: N/A.