Placenta Accreta Spectrum After Myomectomy: A Systematic Review and Meta-Analysis Stratified by Surgical Approach.

BackgroundWe aimed to evaluate the risk of perinatal complications in subsequent pregnancies after different types of myomectomy, viz. open, laparoscopic, or hysteroscopic. Moreover, we investigated whether the time interval from myomectomy to subsequent pregnancy (TIMP) is a risk factor for perinatal complications.MethodsThis retrospective cohort study analyzed data from the vast Japanese health insurance JMDC database between January 2008 and July 2024. We identified primiparous women and excluded participants based on the following criteria: age < 20 years at delivery, diagnosis of adenomyosis, multiple pregnancy, or history of repeated myomectomy using different approaches. The occurrence of placenta accreta spectrum (PAS), placenta previa, uterine rupture, gestational hypertension/preeclampsia, and placental abruption was compared among women who underwent open, laparoscopic, or hysteroscopic myomectomy and those in the control group. Subsequently, for each myomectomy procedure, we compared the TIMP between women with and without each perinatal complication. Fisher’s exact test and multivariable logistic regression models were employed.ResultsAmong the 27,129 eligible women, 140, 305, and 97 underwent open, laparoscopic, and hysteroscopic myomectomy, respectively. The proportion of PAS was the highest in the hysteroscopic group (5.2%), followed by the control (1.8%), open (1.4%), and laparoscopic (1.3%) groups. After adjustment, there was no association between PAS and hysteroscopic myomectomy (adjusted odds ratio, 1.86; 95% confidence interval, 0.75–4.63). Uterine rupture after myomectomy was observed only in the laparoscopic surgery group (1.0%); this difference among the four groups was statistically significant (Fisher’s exact test, P = 0.001), although a robust adjusted analysis was not feasible due to the low incidence rate. The proportion of gestational hypertension/preeclampsia was the highest in the hysteroscopic group (17.5%); however, a similar trend was observed as for PAS (adjusted odds ratio, 1.30; 95% confidence interval, 0.74–2.27). The incidences of placenta previa and placental abruption did not differ significantly among the groups. The TIMP was the shortest after hysteroscopic myomectomy, followed by laparoscopic and open myomectomy. Although the number of outcomes was small, which constrained clinical interpretation, there were no perinatal complications associated with TIMP.ConclusionOur study suggested the potential risk of uterine rupture after laparoscopic myomectomy. The optimal TIMP remains unclear. The risks of perinatal complications after myomectomy should be assessed and addressed at the individual level based on the specific myomectomy method, but further research on the optimal TIMP is warranted.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12884-025-08617-6.

Previous preterm cesarean delivery and risk of uterine rupture in subsequent trial of labor—a national cohort study

Assessment of placenta accreta spectrum at vaginal birth after cesarean delivery

First-trimester prediction of uterine rupture in cesarean scar pregnancy

BackgroundRetained products of conception (RPOC) often cause severe postpartum hemorrhage (PPH) but the clinical significance of RPOC in placenta previa is unclear. This study aimed to investigate the clinical significance of RPOC in women with placenta previa. The primary outcome was to evaluate risk factors of RPOC and the secondary outcome was to consider risk factors of severe PPH.MethodsSingleton pregnant women with placenta previa who underwent cesarean section (CS) and placenta removal during the operation at the National Defense Medical College Hospital between January 2004 and December 2021 were identified. A retrospective analysis was performed to examine the frequency and risk factors of RPOC and the association of RPOC with severe PPH in pregnant women with placenta previa.ResultsThis study included 335 pregnant women. Among these, 24 (7.2%) pregnant women developed RPOC. Pregnant women with prior CS (Odds Ratio (OR) 5.98; 95% Confidence Interval (CI) 2.35–15.20, p < 0.01), major previa (OR 3.15; 95% CI 1.19–8.32, p < 0.01), and placenta accreta spectrum (PAS) (OR 92.7; 95% CI 18.39–467.22, p < 0.01) were more frequent in the RPOC group. Multivariate analysis revealed that prior CS (OR 10.70; 95% CI 3.47–33.00, p < 0.01,) and PAS (OR 140.32; 95% CI 23.84–825.79, p < 0.01) were risk factors for RPOC. In pregnant women who have placenta previa with RPOC or without RPOC, the ratio of severe PPH were 58.3% and 4.5%, respectively (p < 0.01). Furthermore, the occurrence of prior CS (OR 9.23; 95% CI 4.02–21.20, p < 0.01), major previa (OR 11.35; 95% CI 3.35–38.38, p < 0.01), placenta at the anterior wall (OR 3.44; 95% CI 1.40–8.44, p = 0.01), PAS (OR 16.47; 95% CI 4.66–58.26, p < 0.01), and RPOC (OR 29.70; 95% CI 11.23–78.55, p < 0.01) was more in pregnant women with severe PPH. In the multivariate analysis for severe PPH, prior CS (OR 4.71; 95% CI 1.29–17.13, p = 0.02), major previa (OR 7.50; 95% CI 1.98–28.43, p < 0.01), and RPOC (OR 13.26; 95% CI 3.61–48.63, p < 0.01) were identified as risk factors.ConclusionsPrior CS and PAS were identified as risk factors for RPOC in placenta previa and RPOC is closely associated with severe PPH. Therefore, a new strategy for RPOC in placenta previa is needed.

Early first-trimester transvaginal ultrasound is indicated in pregnancy after previous Cesarean delivery: should it be mandatory?

Background: Prior prelabor cesarean delivery (CD) was associated with an increase in the risk of placenta previa (PP) in a second delivery, whether it may impact postpartum hemorrhage (PPH) independent of abnormal placentation. This study aimed to assess the risk of PPH stratified by abnormal placentation following a first CD before the onset of labor (prelabor) or intrapartum CD.Methods: This multicenter, historical cohort study involved singleton, pregnant women at 28 weeks of gestation or greater with a CD history between January 2017 and December 2017 in 11 public tertiary hospitals within 7 provinces of China. PPH was analyzed in the subsequent pregnancy between women with prior prelabor CD and women with intrapartum CD. Furthermore, PPH was analyzed in pregnant women stratified by complications with PP alone [without placenta accreta spectrum (PAS) disorders], complications with PP and PAS, complications with PAS alone (without PP), and normal placentation. We performed multivariate logistic regression to calculate adjusted odds ratios (aOR) and 95% CI controlling for predefined covariates.Results: Out of 10,833 pregnant women, 1,197 (11%) women had a history of intrapartum CD and 9,636 (89%) women had a history of prelabor CD. Prior prelabor CD increased the risk of PP (aOR 1.91, 95% CI 1.40–2.60), PAS (aOR 1.68, 95% CI 1.11–2.24), and PPH (aOR 1.33, 95% CI 1.02–1.75) in a subsequent pregnancy. After stratification by complications with PP alone, PP and PAS, PAS alone, and normal placentation, prior prelabor CD only increased the risk of PPH (aOR 3.34, 95% CI 1.35–8.23) in a subsequent pregnancy complicated with PP and PAS.Conclusion: Compared to intrapartum CD, prior prelabor CD increased the risk of PPH in a subsequent pregnancy only when complicated by PP and PAS.

IntroductionPlacental abruption is a serious complication, especially when accompanied by intrauterine fetal death. The optimal delivery route for placental abruption with intrauterine fetal death for reducing maternal complications is still unclear. In this study we aimed to compare the maternal outcomes between cesarean delivery and vaginal delivery in women with placental abruption with intrauterine fetal death.Material and methodsUsing the Japan Society of Obstetrics and Gynecology nationwide perinatal registry database, we identified pregnant women with placental abruption with intrauterine fetal death between 2013 and 2019. The following women were excluded: those with multiple pregnancies, placenta previa, placenta accreta spectrum, amniotic fluid embolism, or whose delivery route was missing data. The association between delivery routes (cesarean delivery and vaginal delivery) and the maternal outcome was examined using a linear regression model with inverse probability weighting. The primary outcome was the amount of bleeding during delivery. Missing data were imputed using multiple imputation.ResultsThe number of women with placental abruption with intrauterine fetal death was 1218/1601932 (0.076%). Of 1134 women analyzed, 608 (53.6%) underwent cesarean delivery. Bleeding during delivery (median [interquartile range]) was 1650.00 (950.00–2450.00) (mL) and 1171.00 (500.00–2196.50) (mL) in cesarean and vaginal delivery, respectively. Bleeding during delivery (mL) was significantly greater in cesarean delivery than in vaginal delivery (regression coefficient, 1086.39; 95% confidence interval, 130.96–2041.81; p = 0.026). Maternal death and uterine rupture occurred in four (0.4%) and five (0.4%) women, respectively. The four maternal deaths were noted in the vaginal delivery group.ConclusionsBleeding during delivery was significantly greater in cesarean delivery than that in vaginal delivery in women with placental abruption with intrauterine fetal death. However, severe complications, including maternal death and uterine rupture, occurred in vaginal delivery‐related cases. The management of women with placental abruption with intrauterine fetal death should be cautious regardless of the delivery route.

Pathologically diagnosed placenta accreta spectrum without placenta previa: a systematic review and meta-analysis

Placenta accreta spectrum (PAS) is described as a partial or total lack of decidua with adherence or invasion of the placenta to the myometrium and is a major cause of postpartum hemorrhage and peripartum hysterectomy. The risk of PAS is approximately 1 in 272 in the United States. Prior uterine surgeries including myomectomy disrupt the integrity of the endometrium and myometrium and may increase the risk of PAS. However, the association between myomectomy and PAS remains controversial. This retrospective nationwide cohort study aimed to investigate the effect of myomectomy, stratified by method of myomectomy, on the risk of PAS. Data were obtained from the Taiwan National Health Insurance Research Database, which includes prenatal, perinatal, demographic, and treatment data on nearly all pregnant patients in Taiwan. All pregnant people who gave birth after 20 weeks of gestation between January 2008 and December 2017 were included. Patients with incomplete data, previous history of PAS before myomectomy, robotic-assisted myomectomy, or a diagnosis of adenomyosis were excluded. Patients were classified into 3 groups according to method of myomectomy: laparotomic, laparoscopic, and hysteroscopic. A 1:1 propensity-score estimation matching with logistic regression was used for patients with and without history of myomectomy to minimize selection bias. The primary outcome was placenta accreta, whereas secondary outcomes included placenta previa, postpartum hemorrhage, placenta abruption, uterine rupture, and preterm delivery. Logistic regression models were used to analyze the association between myomectomy and adverse pregnancy outcomes and the risk of placenta accreta for the entire population. Analysis of variance and post hoc tests were used to analyze differences in clinical characteristics and adverse pregnancy outcomes according to different methods of myomectomy. A total of 1,393,628 patients were included in this study. Among them, 11,255 patients had a history of myomectomy. Placenta accreta spectrum occurred in 0.96% of those with a history of myomectomy and 0.20% of those without. The risk of PAS was significantly higher in patients with a history of myomectomy, compared with those without (adjusted odds ratio, 2.28; confidence interval [CI], 1.85–2.81; P &lt; 0.01). There was an elevated risk of other adverse pregnancy outcomes including placenta previa, postpartum hemorrhage, cesarean hysterectomy, uterine rupture, preterm delivery, and placenta abruption among those with a history of myomectomy compared with those without. The presence of placenta previa significantly increased risk of PAS, as did the number of prior myomectomies. The propensity score–matched cohort analysis found a similar increase in PAS risk associated with myomectomy. Compared with subjects without a history of myomectomy, the risk of PAS was greater after hysteroscopic (adjusted odds ratio, 3.88; 95% CI, 2.68–5.63), laparoscopic (2.02; 95% CI, 2.79–5.62), and laparotomic myomectomy (1.86; 95% CI, 1.33–2.60). The results of this study find that a history of myomectomy is significantly associated with increased risk of PAS in subsequent pregnancies. Hysteroscopic myomectomy was associated with the highest risk of PAS, and the presence of placenta previa or history of multiple myomectomies further increased the risk.

To develop nomograms predicting the risk of postpartum hemorrhage (PPH) in cesarean delivery for singleton pregnant women with a scarred uterus in the north of China. A retrospective cohort study was conducted. Totally 3722 singleton pregnant women with a scarred uterus who underwent a cesarean delivery in a large teaching hospital of north China between January 2013 and December 2017 were enrolled. Nomograms, a kind of user-friendly tool, were developed to predict PPH (blood loss ≥1000 mL or accompanied by signs or symptoms of hypovolemia within 24 h after the birth process) based on the model generated by logistic regression analysis. The discrimination and calibration of models were evaluated, and decision curve analysis was developed. Among 3722 enrolled women, 243 (6.53%) had PPH. There are six identified factors associated with PPH: maternal age, placental location, placenta previa, hypertensive disorders of pregnancy, fetal position and placenta accreta spectrum (PAS). The model achieved a good calibration (Hosmer-Lemeshow test P value 0.77) and discrimination (area under curve c-statistics 0.90, 95% confidence interval 0.86-0.93). Decision curve analysis showed the threshold probability by using our model is between 1.0% and 85.7%. A nomogram was developed accordingly. And another nomogram for women without placenta previa and PAS was also developed. Two nomograms were first generated to predict PPH, respectively, for women with a scarred uterus and for women with a scarred uterus who do not have placenta previa or PAS. Placental location and fetal position were found to be closely related to PPH.

In vitro fertilization as an independent risk factor for placenta accreta spectrum

Placenta accreta spectrum (PAS) refers to excessive placental invasion into the maternal uterus and it is associated with high risk of obstetric haemorrhage and adverse maternal-neonatal outcomes. Currently, no specific circulating biomarkers of PAS have been identified. Given that in PAS disorders, the depth and the extension of placental invasion into the uterus are expected to be increased, in this study, we analysed plasma levels of syncytiotrophoblast-derived extracellular vesicles (STBEVs) in women with placenta previa (PP), at a high risk of PAS disorders, and pregnant women with normal placentation. Venous blood samples were collected from 35 women with ultrasonographic diagnosis of PP and 35 women with normal placentation, matched for gestational age. Plasma samples were ultracentrifuged at 120.000 g to collect extracellular vesicles (EVs). To identify and quantify plasma placenta–derived EVs (or STBEVs), EVs were analysed by flow cytometry using a monoclonal antibody against placental alkaline phosphatase (PLAP). Plasma levels of STBEVs were significantly higher in PP patients compared to controls. Plasma levels of STBEVs in women with PP and PAS showed a trend to a higher concentration compared to women with PP without PAS, although not reaching a statistical significance. Circulating STBEVs are potential candidates as biological markers to be integrated to ultrasonography in the antenatal screening programme for PAS. More studies are needed to confirm our observation in a larger cohort of patients and to analyse a possible association between high circulating levels of STBEVs and PAS.

Massive hemorrhage due to placenta previa with placenta accreta spectrum is associated with high maternal mortality and morbidity. Therefore, accurate prediction of placenta previa with placenta accreta spectrum is essential; magnetic resonance imaging (MRI) is a useful tool for this purpose. This study investigated novel predictors of anterior and posterior placenta previa with placenta accreta spectrum using MRI. This was a retrospective study at a tertiary obstetrics hospital in Japan. The singleton patients with placenta previa who were scanned with MRI prenatally and had a cesarean section at our institution between 2007 and 2018 were included. The prediction of anterior and posterior placenta previa with placenta accreta spectrum was evaluated using four MRI findings: heterogeneous signals in the placenta, dark T2-weighted intraplacental bands, myometrial thinning or interruption, and focal uterine bulging. The prediction of posterior placenta previa with placenta accreta spectrum was performed using the quantification of cervical varicosities, which were defined as the ratio of the distance between the minimum distance from the most dorsal cervical varicosities (a) to the deciduous and amniotic placenta (b) on a sagittal image. Among 202 patients, 14 (6.9%) patients were pathologically diagnosed as having placenta accreta spectrum. Further, 38 (18.8%) patients had anterior placenta previa and 164 (81.2%) patients had posterior placenta previa. When anterior placenta previa with placenta accreta spectrum was predicted using at least one of the four MRI findings, the sensitivity and specificity of the anterior placenta previa with placenta accreta spectrum were 87.5% and 86.7%, respectively. In contrast, the sensitivity and specificity of posterior placenta previa with placenta accreta spectrum were 42.9% and 96.2%, respectively. But when the A/B ratio was set at 0.20, the sensitivity and specificity of the prediction for posterior placenta previa with placenta accreta spectrum using cervical varicosities were 100.0% and 89.2%, respectively. The findings of MRI to predict the anterior placenta previa with placenta accreta spectrum were different from posterior placenta previa. The cervical varicosities may be useful in predicting posterior placenta previa with placenta accreta spectrum.

Postpartum haemorrhage (PPH) causes substantial morbidity and mortality worldwide. A reliable prognostic tool for PPH has potential to aid prevention efforts. Systematically to identify and appraise prognostic modelling studies for prediction of PPH. MEDLINE, Embase, CINAHL and the Cochrane Library were searched using a combination of terms and synonyms including 'prediction tool', 'risk score' and 'postpartum haemorrhage'. Any observational or experimental study developing a prognostic model for women's risk of PPH. English language publications. Predesigned data extraction form to record: data source; participant criteria; outcome; candidate predictors; actual predictors; sample size; missing data; model development; model performance; model evaluation; interpretation. Of 2146 citations screened, 14 studies were eligible for inclusion. Studies addressed populations of women who experienced placenta praevia, placenta accreta spectrum, vaginal birth, caesarean birth (CS) and the general obstetric population. All studies were at high risk of bias due to low sample size, no internal validation, suboptimal or no external validation or no reporting or handling of missing data. Five studies raised applicability concerns. Three externally validated and three internally validated studies show potential for robust external validation. Of 14 prognostic models for PPH risk, three have some potential for clinical use: in CS, in placenta accreta spectrum disorders with MRI placental Evaluation and in placenta praevia. Future research requires robust internal and external validation of existing tools and development of a model for use in the general obstetric population. Current PPH prediction tools need external validation: one for CS, one for placenta praevia and one for placenta accreta. Tools are needed for labouring women.