Delivery outcomes in the subsequent pregnancy following the conservative management of placenta accreta spectrum disorder: a systematic review and meta-analysis.

OBJECTIVE: Cesarean hysterectomy is generally presumed to decrease maternal morbidity and mortality secondary to placenta accreta spectrum disorder. Recently, uterine-sparing techniques have been introduced in conservative management of placenta accreta spectrum disorder to preserve fertility and potentially reduce surgical complications. However, despite patients often expressing the intention for future conception, few data are available regarding the subsequent pregnancy outcomes after conservative management of placenta accreta spectrum disorder. Thus, we aimed to perform a systematic review and meta-analysis to assess these outcomes. DATA SOURCES: PubMed, Scopus, and Web of Science databases were searched from inception to September 2022. STUDY ELIGIBILITY CRITERIA: We included all studies, with the exception of case studies, that reported the first subsequent pregnancy outcomes in individuals with a history of placenta accreta spectrum disorder who underwent any type of conservative management. METHODS: The R programming language with the "meta" package was used. The random-effects model and inverse variance method were used to pool the proportion of pregnancy outcomes. RESULTS: We identified 5 studies involving 1458 participants that were eligible for quantitative synthesis. The type of conservative management included placenta left in situ (n=1) and resection surgery (n=1), and was not reported in 3 studies. The rate of placenta accreta spectrum disorder recurrence in the subsequent pregnancy was 11.8% (95% confidence interval, 1.1-60.3; I2=86.4%), and 1.9% (95% confidence interval, 0.0-34.1; I2=82.4%) of participants underwent cesarean hysterectomy. Postpartum hemorrhage occurred in 10.3% (95% confidence interval, 0.3-81.4; I2=96.7%). A composite adverse maternal outcome was reported in 22.7% of participants (95% confidence interval, 0.0-99.4; I2=56.3%). CONCLUSION: Favorable pregnancy outcome is possible following successful conservation of the uterus in a placenta accreta spectrum disorder pregnancy. Approximately 1 out of 4 subsequent pregnancies following conservative management of placenta accreta spectrum disorder had considerable adverse maternal outcomes. Given such high incidence of adverse outcomes and morbidity, patient and provider preparation is vital when managing this population.

A risk factor profile for placenta accreta spectrum in pregnancies conceived with assisted reproductive technology.

Objective: To identify independent risk factors for placenta accreta spectrum among pregnancies conceived with assisted reproductive technology. Design: Retrospective cohort study. Setting: Tertiary hospital. Patients: Individuals who conceived with assisted reproductive technology and reached 20 weeks' gestation or later from 2011 to 2017. Interventions: Patient and cycle data was abstracted from hospital records and supplemented with state-level data. Poisson regression was used for multivariate analyses and reported as adjusted relative risks (aRR). Main Outcome Measures: Clinical or histologic placenta accreta spectrum. Results: Of 1,975 qualifying pregnancies, 44 (2.3%) met criteria for accreta spectrum at delivery. In the multivariate model, significant risk factors included low-lying placenta at delivery (aRR, 15.44; 95% CI 7.76-30.72), uterine factor infertility or prior uterine surgery (aRR, 4.68; 95% CI, 2.72-8.05), initial low-lying placentation that resolved (aRR, 3.83; 95% CI, 1.90-7.73), and use of frozen embryos (aRR, 3.02; 95% CI, 1.66-5.48). When the fresh vs frozen variable was replaced with controlled ovarian hyperstimulation, the final model did not change (aRR, 2.40 for unstimulated cycles, 95% CI, 1.32-4.38). With frozen transfers, the accreta rate was 16% when the endometrial thickness was < 6mm vs 3.8% with thicker endometrium (P=.02). Conclusions: Among pregnancies conceived with assisted reproductive technology, accreta spectrum is associated with low placental implantation (even when resolved), uterine factor infertility and prior uterine surgery, and the use of frozen embryo transfer or unstimulated cycles.

Incidence and Clinical Implications of Placenta Accreta Spectrum after Treatment for Asherman Syndrome.

STUDY OBJECTIVE: To investigate the incidence, predictors, and clinical implications of placenta accreta spectrum (PAS) in pregnancies after hysteroscopic treatment for Asherman syndrome (AS). DESIGN: This is a retrospective cohort study, conducted through a telephone survey and chart review. SETTING: Minimally invasive gynecologic surgery center in an academic community hospital. PATIENTS: Database of 355 patients hysteroscopically treated for AS over 4 years. We identified patients who achieved pregnancy past the first trimester and evaluated the incidence and predictors for PAS as well as associated clinical implications. INTERVENTIONS: Telephone survey. MEASUREMENTS AND MAIN RESULTS: We identified 97 patients meeting the inclusion criteria. Among these patients, 23 (23.7%) patients had PAS. History of cesarean delivery was the only variable statistically significantly associated with having PAS (adjusted odds ratio 4.03, 95% confidence interval 1.31-12.39). PAS was diagnosed antenatally in 3 patients (14.3%), with patients having placenta previa more likely to be diagnosed (p <.01). Nine patients (39.13%) with PAS required cesarean hysterectomy, which is 9.3% of those with a pregnancy that progressed past the first trimester. Factors associated with cesarean hysterectomy were the etiology of AS (dilation and evacuation after the second trimester pregnancy or postpartum instrumentation, p <.01), invasive placenta (increta or percreta, p <.05), and history of morbidly adherent placenta in previous pregnancies (p <.05). Two patients with PAS (9.5%) had uterine rupture, and another 2 (9.5%) experienced uterine inversion. CONCLUSION: There is a high incidence of PAS and associated morbidity in pregnancies after hysteroscopic treatment for AS. There is a low rate of antenatal diagnosis as well as a lack of reliable clinical predictors, which both stress the importance of clinical awareness, careful counseling, and delivery planning.

Retained placenta after vaginal delivery: risk factors and management.

Retained placenta after vaginal delivery is diagnosed when a placenta does not spontaneously deliver within a designated amount of time, variably defined as a period of 18-60 mins. It may also be diagnosed if a patient experiences significant hemorrhage prior to delivery of the placenta. Normal placenta delivery requires adequate uterine contractions, with shearing of the placenta and decidua from the uterine wall and expulsion of the tissue. Thus, retained placenta can occur in the setting of significant uterine atony, abnormally adherent placenta, as with placenta accreta spectrum (PAS), or closure of the cervix prior to placental expulsion. Risk factors for retained placenta parallel those for uterine atony and PAS and include prolonged oxytocin use, high parity, preterm delivery, history of uterine surgery, and IVF conceptions. History of a prior retained placenta and congenital uterine anomalies also appear to be risk factors. Management entails manual removal of the placenta with adequate analgesia, as medical intervention alone has not been proven effective. Complications can include major hemorrhage, endometritis, or retained portions of placental tissue, the latter of which can lead to delayed hemorrhage or infection. Prophylactic antibiotics can be considered with manual placenta removal, though evidence regarding effectiveness is inconsistent. If hemorrhage is encountered, deployment of a massive transfusion protocol, uterine evacuation with suction, and use of intrauterine tamponade, as with an intrauterine balloon, should be initiated immediately. When a separation plane between the placenta and uterus is particularly difficult to create, PAS should be considered, and preparations should be made for hemorrhage and hysterectomy. Patients with risk factors for retained placenta should have a laboratory sample sent for blood type and antibody screening on admission to labor and delivery, and plans should be made for appropriate analgesia and preparations for hemorrhage if a retained placenta is encountered.

Pregnancy of unknown location: Evaluation and management.

Early diagnosis of an extrauterine pregnancy is important for safe and effective management. However, a pregnancy's location often cannot be easily determined with abnormal implantations or prior to 5-6 weeks' gestation. Multiple testing strategies exist to diagnose an abnormal pregnancy when location is unknown, but caution needs to be used to avoid a false diagnosis. Medical treatment is optimal when an abnormal pregnancy is diagnosed early. Because most of these pregnancies are intrauterine, additional testing to localize the pregnancy will allow the correct choice of therapy and avoids unnecessary exposure to a toxic therapy. This testing strategy should be reserved for patients with significant concern for ectopic pregnancy, based on either risk factors or clinical findings. Overuse of this approach can lead to interruption of normal pregnancies.

The Placenta Accreta Spectrum: Epidemiology and Risk Factors.

The placenta accreta spectrum has become an important contributor to severe maternal morbidity. The true incidence is difficult to ascertain, but likely falls near 1/1000 deliveries. This number seems to have increased along with the rate of risk factors. These include placenta previa, previous cesarean section, use of assisted reproductive technologies, uterine surgeries, and advanced maternal age. With increased uterine conservation, previous retained placenta or placenta accreta have become significant risk factors. Understanding placenta accreta spectrum risk factors facilitates patient identification and safe delivery planning. Patients considering elective uterine procedures or delayed childbirth should consider the impact on peripartum morbidity.

Evaluation of a Quality Improvement Intervention to Increase Vaginal Birth for Twins.

OBJECTIVE: To evaluate whether there was an association between the systematic promotion of twin vaginal delivery and an increase in the rates of twin vaginal birth. METHODS: We conducted a retrospective cohort study. We implemented a quality improvement initiative promoting twin vaginal delivery at an academic tertiary care center in 2013. The program included a needs assessment, simulation of vaginal twin delivery, online educational material, and the expansion of a dedicated twin clinic. We analyzed rates of twin vaginal birth in pregnancies at or beyond 24 weeks of gestation without a contraindication to labor, prior uterine surgery, or a demise or lethal anomaly of either twin. Using linear regression, we calculated annual adjusted rates of twin vaginal birth from 2010 to 2015 and in the 3 years before and after our intervention. We performed an interrupted time-series analysis estimating rates of change before and after the intervention to account for the influence of secular trend. RESULTS: Of 1,574 patients delivering twins, 897 (57%) were included, with 479 in the 3 years before and 418 in the 3 years after the intervention. Adjusted rates of vaginal delivery increased from 32.1% (n=153) to 44.2% (n=185) before and after the intervention (P<.01), with a decrease in elective cesarean delivery from 54.6% (n=479) to 44.3% (n=185) (P<.01). Rates of breech extraction increased after the intervention (5.7% vs 9.3%, P=.04). However, there was no difference in the rate of change in twin vaginal birth in the time period before (1.35% annual increase, P=.76) or after (5.8% annual increase, P=.40) the intervention. CONCLUSIONS: Although we observed an increased rate of twin vaginal birth in the time period after our intervention, because the rates of increase before and after the intervention were not statistically different, the increase is not attributable to our intervention and is more properly attributed to secular trend.

Conservative management of morbidly adherent placenta: expert review.

Over the last century, the incidence of placenta accreta, increta, and percreta, collectively referred to as morbidly adherent placenta, has risen dramatically. Planned cesarean hysterectomy at the time of cesarean delivery is the standard recommended treatment in the United States. Recently, interest in conservative management has resurged, especially in Europe. The aims of this review are the following: (1) to provide an overview of methods used for conservative management, (2) to discuss clinical implications for both clinicians and patients, and (3) to identify areas in need of further research.

Cryopreserved embryo transfer is an independent risk factor for placenta accreta.

OBJECTIVE: To explore the association between cryopreserved embryo transfer (CET) and risk of placenta accreta among patients utilizing in vitro fertilization (IVF) and/or intracytoplasmic sperm injection (ICSI). DESIGN: Case-control study. SETTING: Academic medical center. PATIENT(S): All patients using IVF and/or ICSI, with autologous or donor oocytes, undergoing fresh or cryopreserved transfer, who delivered a live-born fetus at ≥24 weeks of gestation at our center, from 2005 to 2011 (n = 1,571), were reviewed for placenta accreta at delivery. INTERVENTION(S): Cases of accreta (n = 50) were matched by age and prior cesarean section to controls (1:3) without accreta. The association between CET and accreta was modeled using conditional logistic regression, controlling a priori for age and placenta previa. Receiver operating characteristic curves were used to determine thresholds of endometrial thickness and peak serum E2 levels related to accreta. MAIN OUTCOME MEASURE(S): Placenta accreta. RESULT(S): Univariate predictors of accreta were non-Caucasian race (odds ratio [OR] 2.85, 95% confidence interval [CI] 1.25-6.47); uterine factor infertility (OR 5.80, 95% CI 2.49-13.50); prior abdominal or laparoscopic myomectomy (OR 7.24, 95% CI 1.92-27.28); and persistent or resolved placenta previa (OR 4.25, 95% CI 1.94-9.33). In multivariate analysis, we observed a significant association between CET and accreta (adjusted OR 3.20, 95% CI 1.14-9.02), which remained when analyses were restricted to cases of accreta with morbid complications (adjusted OR 3.87, 95% CI 1.08-13.81). Endometrial thickness and peak serum E2 level were each significantly lower in CET cycles and those with accreta. CONCLUSION(S): Cryopreserved ET is a strong independent risk factor for accreta among patients using IVF and/or ICSI. A threshold endometrial thickness and a "safety window" of optimal peak E2 level are proposed for external validation.

Uterine artery embolization of cervical varices before second-trimester abortion.

BACKGROUND: Cervical varices are an extremely rare complication of pregnancy; they can result in significant maternal morbidity secondary to acute hemorrhage. There is limited evidence to guide the management of cervical varices during termination of pregnancy. CASE: A 37-year-old woman presented with recurrent vaginal hemorrhage at 17 weeks of gestation in the setting of a dichorionic-diamniotic twin gestation, an anterior placenta previa, a subchorionic hematoma visible on ultrasound examination, and prominent cervical varices. After extensive counseling, she and her husband opted for termination. Prophylactic uterine artery embolization was performed before uncomplicated laminaria placement and standard dilation and evacuation. CONCLUSION: Prophylactic uterine artery embolization may have reduced hemorrhage risk from cervical varices during dilation and evacuation for second-trimester abortion.