Systematic review and meta-analysis on placenta accreta spectrum disorders in twin pregnancies: risk factors, detection rate and histopathology.

INTRODUCTION: The occurrence of PAS has been recently associated with the presence of twin pregnancy. Aim of this review is to report the risk factors, histopathological correlation, diagnostic accuracy of prenatal ultrasound and clinical outcome of twin pregnancies complicated by placenta accreta spectrum (PAS) disorders. EVIDENCE ACQUISITION: PubMed, Embase, Cinahl, Clinical Trial.Gov and Google Scholar databases were searched. Inclusion criteria were studies on twin pregnancies complicated by PAS. The outcomes explored were risk factors for PAS (including placenta previa, prior uterine surgery or assisted reproductive technology, ART), histopathology (placenta accreta and increta/percreta), detection rate of prenatal ultrasound and clinical outcome, including need for blood transfusion, hysterectomy, emergency or scheduled Cesarean delivery (CD), and maternal death. Random effect meta-analyses of proportions were sued to combine the data. EVIDENCE SYNTHESIS: Two studies considering 103 pregnancies were included in this systematic review: 41.86% (95% CI 27.0-57.9) of twin pregnancies complicated by PAS disorders had a prior CD, 28.22% (95% CI 13.4-46.0) presented placenta previa and 58.14% (95% CI 42.1-73.0) of twin pregnancies were conceived by ART. 74.49% (95% CI 41.6-96.5) of PAS in twin pregnancies were placenta accreta, while 25.51% (95% CI 3.5-58.4) were placenta increta or percreta. Prenatal diagnosis of PAS in twin pregnancies was accomplished only in 27.91% (95% CI 15.3-43.7) of cases. Finally, only one study consistently reported the clinical outcome of PAS in twins. 31.67% (95% CI 20.3-45.0) of women required blood transfusion, 26.67% (95% CI 16.1-39.7) had hysterectomy, while there was no case of maternal death. 44.19% of women had an emergency CD. CONCLUSIONS: There is still limited evidence on the clinical course of PAS disorders in twin pregnancies. Placenta previa, prior uterine surgery (mainly CD), and ART are the most commonly risk factors for PAS disorders in twins. Prenatal diagnosis of PAS in twins is lower compared to what reported in singleton. Finally, about 30% of women with a twin pregnancy complicated by PAS required blood transfusion and hysterectomy.

Outcomes of second stage cesarean section following the use of a fetal head elevation device: A systematic review and meta-analysis.

OBJECTIVES: To explore maternal and perinatal outcomes of women undergoing full dilatation cesarean section (CS) who had compared to those who did not have application of fetal head elevation device (FHED). MATERIAL AND METHODS: Pubmed, Embase, Cinahl, Clinical Trial.Gov and Google Scholar databases were searched. Inclusion criteria were studies exploring maternal and perinatal outcomes in women having compared to those not having FHED at full dilatation CS. The outcomes explored were: hysterotomy to delivery time (sec), mean estimated blood loss (ml), blood loss > 1000 mL, need for blood transfusion, uterine incision extension, operative complications, need for re-operation, urinary retention, hospital re-admission, length of in hospital stay, Apgar score < 3 at 1 min, Apgar score < 7 at 5 min, neonatal arterial Ph, arterial pH < 7.1, admission to neonatal intensive care unit (NICU), neonatal sepsis, need for neonatal endotracheal intubation, neonatal death. Random effect head-to-head meta-analyses combining summary mean difference (MD), and odd ratio (OR) were used to analyze the data. RESULTS: Ten studies (1326 women) were included. The mean time from hysterotomy to delivery was lower in women having compared to those not having FHED (MD: -52.26 s, 95 % CI -55.2 to -34.94, p < 0.001). Women who had FHED had also a lower mean estimated blood loss (MD: -130.82 mL, 95 % CI -130.1 to -381.0; p < 0.001) and a shorter stay in the hospital (MD: -0.884 h, 95 % CI -1.07 to -0.70; p < 0.001) compared to controls. Pregnant women having FHED at full dilatation CS had a lower risk of uterine incision extension (OR: 0.50, 95 % CI 0.3 to 0.9; p = 0.02), need for blood transfusion (OR: 0.39, 95 % CI 0.2 to 0.7; p = 0.04) and operative complications (OR: 0.44, 95 % CI 0.2 to 0.9; p = 0.03) compared to controls, while there was no difference in the other maternal outcomes between the two groups. When exploring perinatal outcome, women who received FHED had higher mean arterial pH values (MD: 0.617, 95 % CI 0.43 to 0.88; p < 0.001) and a lower risk of neonatal sepsis (OR: 0.10, 95 % CI 0.01 to 0.99; p = 0.05) and admission to NICU (OR: 0.63, 95 % CI 0.5 to 0.9; p = 0.008) compared to controls. CONCLUSION: Application of FHED at full dilatation CS seems to be associated with improvement in some maternal and neonatal outcomes.

Placental histopathology after SARS-CoV-2 infection in pregnancy: a systematic review and meta-analysis.

OBJECTIVE: This study aimed to report the spectrum of placental pathology findings in pregnancies complicated by SARS-CoV-2 infection. DATA SOURCES: MEDLINE, Embase, Google Scholar, and the Web of Science databases were searched up to August 11, 2021. STUDY ELIGIBILITY CRITERIA: Histopathologic anomalies included maternal vascular malperfusion, fetal vascular malperfusion, acute inflammatory pathology, chronic inflammatory pathology, increased perivillous fibrin, and intervillous thrombosis. Moreover, subanalyses of symptomatic women only and high-risk pregnancies were performed. METHODS: Histopathologic analysis of the placenta included gross examination, histopathology on hematoxylin and eosin, immunohistochemistry, fluorescence in situ hybridization, quantitative reverse transcription-polymerase chain reaction on placental tissue, and transmission electron microscope. Random-effect meta-analyses were used to analyze the data. RESULTS: A total of 56 studies (1008 pregnancies) were included. Maternal vascular malperfusion was reported in 30.7% of placentas (95% confidence interval, 20.3-42.1), whereas fetal vascular malperfusion was observed in 27.08 % of cases (95% confidence interval, 19.2-35.6). Acute and chronic inflammatory pathologies were reported in 22.68% (95% confidence interval, 16.9-29.0) and 25.65% (95% confidence interval, 18.4-33.6) of cases, respectively. Increased perivillous fibrin was observed in 32.7% (95% confidence interval, 24.1-42.0) of placentas undergoing histopathologic analysis, whereas intervillous thrombosis was observed in 14.6% of cases (95% confidence interval, 9.7-20.2). Other placental findings, including a basal plate with attached myometrial fibers, microscopic accretism, villous edema, increased circulating nucleated red blood cells, or membranes with hemorrhage, were reported in 37.5% of cases (95% confidence interval, 28.0-47.5), whereas only 17.5% of cases (95% confidence interval, 10.9-25.2) did not present any abnormal histologic findings. The subanalyses according to maternal symptoms owing to SARS-CoV-2 infection or the presence of a high-risk pregnancy showed a similar distribution of the different histopathologic anomalies to that reported in the main analysis. Moreover, the risk of placental histopathologic anomalies was higher when considering only case-control studies comparing women with SARS-CoV-2 infection with healthy controls. CONCLUSION: In pregnant women with SARS-CoV-2 infection, a significant proportion of placentas showed histopathologic findings, suggesting placental hypoperfusion and inflammation. Future multicenter prospective blinded studies are needed to correlate these placental lesions with pregnancy outcomes.