Risk of placenta accreta spectrum following myomectomy: a nationwide cohort study

Abstract

BackgroundWhether myomectomy increases the risk of placenta accreta spectrum (PAS) in the following pregnancies remains controversial. ObjectiveThis study aimed to investigate the effect of myomectomy on the risk of placenta accreta spectrum in the following pregnancies. Different methods of myomectomy on the risk of placenta accreta spectrum were also explored. Study designA nationwide cohort study was conducted using data from the Taiwan National Health Insurance Research Database including all pregnant patients in Taiwan who gave birth between January 2008 and December 2017. A 1:1 propensity-score estimation matching was performed for the analysis of myomectomy on the risk of placenta accreta spectrum. Among pregnant patients who received myomectomy, different methods of myomectomy on the risk of placenta accreta spectrum were compared with control group. ResultsAmong the 1,371,458 pregnant patients in this study, there were 11,255 pregnant patients who had history of myomectomy. The risk of PAS in pregnant patients with history of myomectomy was higher than pregnant patients without history of myomectomy (incidence 0.96% vs. 0.20%, adjusted odds ratio 2.28, 95% CI 1.85-2.81, p<0.01). Among pregnant patients with history of myomectomy, 5,045 (46.87%) pregnant patients received laparotomic myomectomy, 3,973 (36.93%) received laparoscopic myomectomy, and 1,742 (16.20%) received hysteroscopic myomectomy. The incidence of PAS in the hysteroscopic group was higher than that in the laparotomic group or the laparoscopic group (1.89%, 0.71%, and 0.81% respectively, p<0.05 vs. the hysteroscopic group). The adjusted odds ratio for PAS was 3.88 (95% CI 2.68-5.63) in the hysteroscopic group compared to subjects without history of myomectomy (p<0.05). ConclusionMyomectomy, especially hysteroscopic myomectomy, is associated with increased risk of PAS in the subsequent pregnancy.