Diagnosis and Management of Cesarean Scar Pregnancy and Placenta Accreta Spectrum: Case Series and Review of the Literature

Early first-trimester transvaginal ultrasound screening for cesarean scar pregnancy in patients with previous cesarean delivery: analysis of the evidence

Obstetric hemorrhage is a leading cause of maternal morbidity and mortality. An important etiology of obstetric hemorrhage is placenta accreta spectrum. In the last 2 decades, there has been increased clinical experience of the devastating effect of undiagnosed, as well as late diagnosed, cases of cesarean scar pregnancy. There is a growing body of evidence suggesting that cesarean scar pregnancy is an early precursor of second- and third-trimester placenta accreta spectrum. As such, cesarean scar pregnancy should be diagnosed in the early first trimester. This early diagnosis could be achieved by introducing regimented sonographic screening in pregnancies of patients with previous cesarean delivery. This opinion article evaluates the scientific and clinical basis of whether cesarean scar pregnancy, with special focus on its early first-trimester discovery, complies with the accepted requirements of a screening test. Each of the 10 classical screening criteria of Wilson and Jungner were systematically applied to evaluate if the criteria were met by cesarean scar pregnancy, to analyze if it is possible and realistic to carry out screening in a population-wide fashion.

A Single-Centre Retrospective Analysis of Pregnancies with Placenta Accreta Spectrum (PAS): From One-Step Surgery towards Two-Step Surgical Approach

Background: Placenta accreta spectrum (PAS) can be the cause of major morbidity and its optimal management is still controversial. The aim of this study was to compare the traditional one-step surgery with a two-step surgical approach in which the placenta is left in situ and the second final operation is delayed to minimise blood loss. Methods: We conducted a single-centre retrospective cohort study including all patients managed for PAS between 2007 and 2023. The number of units of red blood cells (RBCs) needed during surgery was the primary outcome used to compare these two approaches. Results: A total of 43 cases were included in this analysis. Twenty of these were managed with the delayed two-step surgical approach, whereas 23 received one-step surgery. The median estimated blood loss during surgery was 2000 mL and 2800 mL for two-step and one-step surgery, respectively (p = 0.095). In the two-step surgical approach, the median number of RBC units transfused during surgery was significantly lower (p = 0.049) and the odds ratio for needing more than four units of RBCs was 0.28 (95%-CI: 0.08-0.98, p = 0.043). A longer interval between the caesarean section and the second operation showed a trend toward lower blood loss (p = 0.065) and was associated with a significantly lower number of RBC units needed during surgery (p = 0.019). Conclusions: Two-step surgery for the treatment of PAS was safe in our cohort and could lead to a reduction in blood transfusion. Leaving the placenta in situ and delaying the final operation represents a possible alternative to traditional caesarean hysterectomy.

Dichorionic diamniotic heterotopic twin gestation with cesarean section scar implantation and placenta increta

Heterotopic cesarean scar pregnancy is an extremely rare form of pregnancy and is defined as an intrauterine pregnancy coexisting with an ectopic pregnancy implanted in the cesarean scar. Cesarean scar ectopic pregnancy can also be a precursor for placenta accreta spectrum, a potentially life-threatening condition in which the placenta is abnormally adherent to the uterine myometrium and possibly adjacent organs. Although cesarean scar ectopic pregnancies are rare, there has been an increase in their incidence due to the rise in cesarean deliveries. We present the case of a 35-year-old patient with a heterotopic pregnancy with ectopic implantation in a cesarean scar and associated placenta increta, as well as the radiologic evaluation of placenta accreta spectrum and subsequent management.

Focal Placenta Accreta in a Congenitally Malformed Uterus: A Case Report

Placenta accreta is defined as an abnormal trophoblast invasion of part or all of the placenta into the myometrium of the uterine wall. It is a well-known cause of maternal morbidity and mortality. Here, we present a unique case of focal placenta accreta due to a bicornuate uterus and a history of septum resection. We also discuss its management and outcome. The patient underwent a classical cesarean section and reinforcement of the anterior and posterior uterine wall. The patient had a history of surgery for correction of uterine malformation, which may have resulted in an abnormal adherence of the placenta.

Cesarean Scar Pregnancy: A systematic review on expectant management

A Cesarean Scar Pregnancy (CSP) is a variant of uterine ectopic pregnancy defined by full or partial implantation of the gestational sac in the scar of a previous cesarean section. The continuous increase of Cesarean Deliveries is causing a parallel increase in CSP and its complications. Considering its high morbidity, the most usual recommendation has been termination of pregnancy in the first trimester; however, several cases progress to viable births. The aim of this systematic review is to evaluate the outcome of CSP managed expectantly and understand whether sonographic signs could correlate to the outcomes. An online-based search of PubMed and Cochrane Library Databases was used to gather studies including women diagnosed with a CSP who were managed expectantly. The description of all cases was analysed by the authors in order to obtain information for each outcome. 47 studies of different types were retrieved, and the gestational outcome was available in 194 patients. Out of these, 39 patients (20,1%) had a miscarriage and 16 (8,3%) suffered foetal death. 50 patients (25,8%) had a term delivery and 81 (41,8%) patients had a preterm birth, out of which 27 (13,9%) delivered before 34 weeks of gestation. In 102 (52,6%) patients, a hysterectomy was performed. Placenta Accreta Spectrum (PAS) was a common disorder among CSP and was linked to a higher rate of complications such as foetal death, preterm birth, hysterectomy, haemorrhagic morbidity and surgical complications. Some of the analysed articles showed that sonographic signs with specific characteristics, such as type II and III CSP classification, Crossover Sign - 1, "In the niche" implantation and lower myometrial thickness could be related to worse outcomes of CSP. This article provides a good understanding of CSP as an entity that, although rare, presents with a high rate of relevant morbidity. It is also understood that pregnancies with confirmed PAS had an even higher rate of morbidity. Some sonographic signs were shown to predict the prognosis of these pregnancies and further investigation is necessary to validate one or more signs so they can be used for a more reliable counselling of women with CSP.

Extravillous trophoblast invasion and decidualization in cesarean scar pregnancies

INTRODUCTION

The increasing cesarean section rate has led to an increase in the number of subsequent pregnancies resulting in a cesarean scar pregnancy. There appears to be preferential attachment of the blastocyst to the scar site, which may be associated with defective decidua in that region, resulting in abnormal implantation, which can in turn negatively affect the success of the pregnancy. The aim of the current study was to evaluate the extravillous trophoblast, decidua, and myometrium in scar and adjacent non-scar regions of the implantation site of a cesarean scar pregnancy.

MATERIAL AND METHODS

Samples containing a gestational mass were obtained by laparoscopic excision from patients with a cesarean scar pregnancy at 6-11 weeks of gestation as diagnosed by transvaginal or transabdominal ultrasound (n = 8 type II cesarean scar pregnancy). Cesarean scar pregnancy tissues were separated into scar and non-scar regions, and the scar regions were sub-separated into non-implantation and implantation sites. Serial sections were histologically examined after hematoxylin and eosin, Masson's trichrome and immunochemical staining, and changes in the myometrium, extravillous trophoblast, and decidua were evaluated.

RESULTS

In cesarean scar pregnancy, compared with scars not in the implantation site, scars in the implantation site displayed increased fibrosis, and had disrupted myometrium, which was related to varying patterns of E-cadherin expression as a response to extravillous trophoblast invasion. In addition, local decidua was found at the non-scar implantation sites, with multinucleated trophoblast giant cell accumulation and shallow invasion. These features were not evident in the scar implantation sites.

CONCLUSIONS

This study emphasizes that the decidua drives multinucleated trophoblast giant cell differentiation, limiting the degree of invasion. Better characterization of this differentiation process may be helpful for better management and avoidance of the consequences of cesarean scar pregnancy.

Risk of Subsequent Hysterectomy after Expectant Management in the Treatment of Placenta Accreta Spectrum Disorders

Management strategies for pregnancies with abnormal adherence/invasion of the placenta (placenta accreta spectrum, PAS) vary between centers. Expectant management (EM), defined as leaving the placenta in situ after the delivery of the baby, until its complete decomposition and elimination, has become a potential option for PAS disorders in selected cases, in which the risk of Caesarean hysterectomy is very high. However, expectant management has its own risks and complications. The aim of this study was to describe the rates of subsequent hysterectomy (HT) in patients that underwent EM for the treatment of PAS disorders. We reviewed the literature on the subject and found 12 studies reporting cases of HT after initial intended EM. The studies included 1918 pregnant women diagnosed with PAS, of whom 518 (27.1%) underwent EM. Out of these, 121 (33.2%) required subsequent HT in the 12 months following delivery. The rates of HT after initial EM were very different between the studies, ranging from 0 to 85.7%, reflecting the different characteristics of the patients and different institutional management protocols. Prospective multicenter studies, in which the inclusion criteria and management strategies would be uniform, are needed to better understand the role EM might play in the treatment of PAS disorders.