Outcome of fetal congenital pulmonary malformations: a systematic review and meta-analysis.

OBJECTIVES: To report the outcome of fetuses with a prenatal diagnosis of congenital lung malformation (CLM) diagnosed on ultrasound by performing a comprehensive assessment of these outcomes through a systematic review and meta-analysis. CONTENT: CLMs are a heterogeneous group of anomalies that involve the lung parenchyma and its bronchovascular structures. Their presentation and evolution are variable, from entirely asymptomatic lesions with sonographic regression in utero to hydropic fetuses requiring fetal therapy, intrauterine death or neonatal morbidity. A systematic review was conducted in Medline, Embase and Cochrane databases including studies on fetuses with CLM diagnosed prenatally in order to report the in-utero natural history of these lesions. Thirty-nine studies (2,638 fetuses) were included in the final review. SUMMARY: Regression/reduction in size of the lung lesion during pregnancy was reported in 31 % of cases, while its increase in 8.5 % of cases. Intra-uterine death complicated 1.5 % of pregnancies with fetal CLM, while neonatal and perinatal death were 2.2 and 3 %, respectively. Neonatal morbidity occurred in 20.6 % of newborns with CLM; 46 % had surgery, mainly elective. In fetuses with CLM and hydrops, fetal/perinatal loss occurred in 42 %. Assessment of the role of fetal therapy in improving the outcomes of pregnancies complicated by CLM was hampered by the small number of included cases and heterogeneity of type of interventions. OUTLOOK: Fetuses with CLM prenatally diagnosed have a generally favorable outcome. Conversely, there is a low quality of evidence on the actual role of fetal therapy in improving the outcome of fetuses presenting with these anomalies.

Counseling in fetal medicine: Congenital cytomegalovirus infection.

Although the clinical work-up of CMV in pregnancy has gradually become more accurate, counseling for CMV is still challenging. Despite the potential feasibility of universal prenatal serological screening, its introduction in prenatal diagnosis continues to raise concerns related to its real cost-effectiveness. Contextually, anticipating the confirmation of fetal infection earlier in pregnancy is one of the most pressing issues to reduce the parental psychological burden. Amniocentesis is still the gold standard and recent data have demonstrated that it could be performed before 20 weeks of gestation, provided that at least 8 weeks have elapsed from the presumed date of maternal seroconversion. New approaches, such as chorionic villus sampling (CVS) and virome DNA, even if not yet validated as confirmation of fetal infection, have been studied alternatively to amniocentesis to reduce the time-interval from maternal seroconversion and the amniocentesis results. Risk stratification for sensorineural hearing loss (SNHL) and long-term sequelae should be provided according to the prognostic predictors. Nevertheless, in the era of valacyclovir, maternal high-dose therapy, mainly for first trimester infections, can reduce the risk of vertical transmission and increase the likelihood of asymptomatic newborns, but it is still unclear whether valacyclovir continues to exert a beneficial effect on fetuses with positive amniocentesis. This review provides updated evidence-based key counseling points with GRADE recommendations.

Cervical length as a screening tool for preterm birth in twin pregnancies: a systematic review and critical evaluation of quality clinical practice guidelines.

OBJECTIVES: Twin pregnancies are at increased risk of preterm birth (PTB) compared to singletons. Evaluation of cervical length (CL) represents the optimal tool to screen PTB in singleton. Conversely, there is less evidence on the use of CL in twins. Our aim was to evaluate the methodological quality and clinical heterogeneity of clinical practice guidelines (CPGs) on the CL application in twins using AGREE II methodology. METHODS: MEDLINE, Scopus, and websites of the main scientific societies were examined. The following aspects were evaluated: diagnostic accuracy of CL, optimal gestational age at assessment and interventions in twin pregnancies with reduced CL. The quality of the published CPGs was carried out using "The Appraisal of Guidelines for REsearch and Evaluation (AGREE II)" tool. The quality of guideline was rated using a scoring system. Each considered item was evaluated by the reviewers on a seven-point scale that ranges from 1 (strongly disagree) to 7 (strongly agree). A cut-off >60 % identifies a CPGs as recommended. RESULTS: The AGREE II standardized domain scores for the first overall assessment had a mean of 74 %. The score was more than 60 % in the 66.6 % of CPGs analyzed indicating an agreement between the reviewers on recommending the use of these CPGs. A significant heterogeneity was found; there was no specific recommendation on CL assessment in about half of the published CPGs. There was also significant heterogeneity on the CL cut-off to prompt intervention. CONCLUSIONS: Despite the fact that the AGREE II analysis showed that the majority of the included guidelines are of good quality, there was a significant heterogeneity among CPGs as regard as the indication, timing, and cut-off of CL in twins as well as in the indication of interventions.

Whole exome sequencing in fetuses with isolated increased nuchal translucency: a systematic review and meta-analysis.

OBJECTIVE: To estimate the incremental yield of detecting pathogenic or likely pathogenic diagnostic genetic variants (DGV) by whole exome sequencing (WES) over standard karyotype and chromosomal microarray (CMA) analyses in fetuses with isolated increased nuchal translucency (NT) and normal fetal anatomy at the time of 11-14 weeks scan. MATERIALS AND METHODS: Medline and Embase databases were searched. Inclusion criteria were fetuses with NT >95th percentile, normal karyotype and CMA and no associated structural anomalies at the time of the 11-14 weeks scan. The primary outcome was to estimate the incremental yield of detecting pathogenic or likely pathogenic genetic variants by WES over standard karyotype and CMA analyses in fetuses with isolated increased nuchal translucency. The secondary outcomes were the detection of a genetic variant of unknown significance. Sub-analysis according to different NT cutoffs (between 3.0 and 5.5 mm and > 5.5 mm) and considering fetuses with isolated NT in which fetal anatomy was confirmed to be normal at the anomaly scan were also performed. Random effects model meta-analyses of proportion were used to analyze the data. RESULTS: Eight articles (324 fetuses) were included in the systematic review. Of the fetuses with negative standard karyotype and CMA analysis, the 8.07% (95% CI 5.4-11.3) had pathogenic or likely pathogenic genetic variants detected exclusively by WES. When stratifying the analysis according to NT cutoffs, genetic anomalies detected exclusively at WES analysis were found in 44.70% (95% CI 26.8-63.4) of fetuses with NT between 3.0 mm and 5.5 mm and 55.3% (95% CI 36.6-73.2) in those fetuses with NT >5.5 mm and positive WES results. The 7.84% (95% CI 1.6-18.2) had variants of unknown significance identified by WES. When considering fetuses with isolated increased NT and normal fetal anatomy at the anomaly scan, the rate of pathogenic or likely pathogenic genetic variants detected by WES was 3.87% (95% CI 1.6-7.1), while variants of unknown significance were detected in 4.27% (95% CI 2.2-7.0) of cases. CONCLUSIONS: Pathogenic and likely pathogenic genetic variants detected by WES are present in a significant proportion of fetuses with increased NT but normal standard karyotype and CMA analysis, also when no anomalies are detected at the anomaly scan. Further large studies sharing objective protocols of imaging assessment are needed to confirm these findings and to elucidate which gene panels should be assessed in fetuses with isolated increased NT to rule out associated genetic anomalies, which may potentially impact post-natal outcomes.

A systematic review and critical evaluation of quality of clinical practice guidelines on fetal growth restriction.

INTRODUCTION: To systematically identify and critically assess the quality of clinical practice guidelines (CPGs) on management fetal growth restriction (FGR). CONTENT: Medline, Embase, Google Scholar, Scopus and ISI Web of Science databases were searched to identify all relevant CPGs on FGR. SUMMARY: Diagnostic criteria of FGR, recommended growth charts, recommendation for detailed anatomical assessment and invasive testing, frequency of fetal growth scans, fetal monitoring, hospital admission, drugs administrations, timing at delivery, induction of labor, postnatal assessment and placental histopathological were assessed. Quality assessment was evaluated by AGREE II tool. Twelve CPGs were included. Twenty-five percent (3/12) of CPS adopted the recently published Delphi consensus, 58.3% (7/12) an estimated fetal weight (EFW)/abdominal circumference (AC) EFW/AC <10th percentile, 8.3% (1/12) an EFW/AC <5th percentile while one CPG defined FGR as an arrest of growth or a shift in its rate measured longitudinally. Fifty percent (6/12) of CPGs recommended the use of customized growth charts to assess fetal growth. Regarding the frequency of Doppler assessment, in case of absent or reversed end-diastolic flow in the umbilical artery 8.3% (1/12) CPGs recommended assessment every 24-48, 16.7% (2/12) every 48-72 h, 1 CPG generically recommended assessment 1-2 times per week, while 25 (3/12) did not specifically report the frequency of assessment. Only 3 CPGs reported recommendation on the type of Induction of Labor to adopt. The AGREE II standardized domain scores for the first overall assessment (OA1) had a mean of 50%. OUTLOOK: There is significant heterogeneity in the management of pregnancies complicated by FGR in published CPGs.

Placenta accreta spectrum disorders clinical practice guidelines: A systematic review.

OBJECTIVES: To objectively assess the quality of the published clinical practice guidelines (CPGs) on the management of pregnancies complicated by placenta accreta spectrum (PAS)disorders. METHODS: MEDLINE, Embase, Scopus, and ISI Web of Science databases were searched. The following aspects related to the management of pregnancies with suspected PAS disorders were evaluated: risk factors for PAS, prenatal diagnosis, role of interventional radiology and ureteral stenting, and optimal surgical management. The assessment of risk of bias and quality assessment of the CPGs were performed using the (AGREE II) tool (Brouwers et al., 2010). To define a CPG as of good quality we adopted a cut-off score >60%. RESULTS: Nine CPGs were included. Specific risk factors for referral were assessed by 44.4% (4/9) of CPGs, mainly consisting in the presence of placenta previa and a prior cesarean delivery or uterine surgery. About 55.6% of CPGs (5/9) suggested ultrasound assessment of women with risk factors for PAS in the second and third trimester of pregnancy and 33.3% (3/9) recommended magnetic resonance imaging (MRI); 88.9% (8/9) of CPGs recommended cesarean delivery at 34-37 weeks of gestation. There was not generally consensus on the use of interventional radiology and ureteral stenting before surgery for PAS. Finally, hysterectomy was the recommend surgical approach by 77.8% (7/9) of the included CPGs. CONCLUSION: Most of the published CPGs on PAS are generally of good quality. There was general agreement among the different CPGs on PAS as a regard as risk stratification, timing at diagnosis and delivery but not on the indication for MRI, use of interventional radiology and ureteral stenting.

Clinical practice guidelines on the use of aspirin in pregnancy: Systematic review.

BACKGROUND: Placental related disorders, including preeclampsia and fetal growth restriction (FGR) are among the main determinants of adverse maternal and perinatal outcomes in both singleton and twin pregnancies. In view of its relevance, aspirin administration is commonly recommended to women at high risk for preeclampsia or FGR by the various national and international guidelines. OBJECTIVES: To establish the clinical heterogeneity among the clinical practice guidelines (CPGs) on aspirin use in pregnancy and to investigate the quality of these CPGs. METHODS: We performed a systematic review of Clinical practice guidelines on main databases searching for all peer-reviewed guidelines into the literature, analyzing the following aspects related to use of aspirin in pregnancy: indications for aspirin administration, dosage, starting of therapy, ending of therapy, safety and side effects. The assessment of risk of bias and quality assessment of the included CPGs were performed using "The Appraisal of Guidelines for REsearch and Evaluation (AGREE II)" tool. RESULTS: 16 CPGs were included. There was an overall general agreement among the published CPGs as regards to the indication for aspirin intake in pregnancy, with prior preeclampsia, chronic hypertension, autoimmune disease, and diabetes mellitus type 1 or 2 recognized as solitary major risk factors for Aspirin administration in 93.7% (15/16) of CPGs. There was heterogeneity in the recommendations provided by the different CPGs as regards the gestational age at which aspirin should be commenced. CONCLUSION: There is general agreement in the reported indications for aspirin intake in pregnancy, with prior preeclampsia and maternal medical co-morbidity associated with increased risk of preeclampsia being the major indications for aspirin intake. Conversely, there was heterogeneity in the recommended dose, gestational age at initiation and discontinuation of therapy among the different CPGs.

Prognostic Value of Amniotic Fluid Viral Load to Predict Adverse Outcome in Pregnancies Complicated by Congenital Cytomegalovirus Infection: A Multicenter Study.

INTRODUCTION: The aim of the study was to report the prognostic value of cytomegalovirus (CMV) viral load in the amniotic fluid (AF) in predicting the outcome of infected pregnancies. METHODS: Multicenter retrospective study involving 11 Italian referral centers from 2012 to 2021 was conducted. Inclusion criteria were fetuses with confirmed congenital CMV infection. The primary outcome was the prognostic value accuracy of CMV quantitative polymerase chain reaction (qPCR) in AF in predicting the risk of additional anomalies detected either at follow-up ultrasound or fetal magnetic resonance imaging (MRI). The secondary outcome was prediction of postnatal clinical symptoms related to CMV infection. Multivariate logistic regression and area under the curve (AUC) analyses were used to analyze the data. RESULTS: 104 fetuses were included. Associated anomalies detected at follow-up ultrasound or fetal MRI were detected in 14.4% of cases (15/104). Mean AF CMV viral load was significantly higher in fetuses with additional anomalies compared to those without additional anomalies at follow-up ultrasound or fetal MRI (3,346,634.27 ± 402,582.95 vs. 761,934 ± 222513,2 p < 0.001). At multivariate logistic regression analysis, CMV AF viral load was independently associated with the presence of additional anomalies at follow-up ultrasound or MRI, with an OR of 1.07 (p = 0.010), while maternal age (p = 0.24), trimester at maternal infection (p = 0.97), and type of infection (primary vs. non-primary) (p = 0.12) were not. CMV AF viral load had AUC of 0.755 for the occurrence of anomalies due to CMV infection, with an optimal cut-off point of >1,310,520 copies/mL, a sensitivity of 66.7%, a specificity of 84.3%, and a positive likelihood ratio of 4.24. Once excluding fetuses with anomalies at ultrasound or MRI, the diagnostic performance of qPCR in identifying fetuses with symptomatic infection after birth was low, with an AUC of 0.586. CONCLUSION: CMV viral load at second trimester amniocentesis has a moderate accuracy for the occurrence of CMV-related anomalies in fetuses with congenital infection and normal ultrasound at the initial diagnosis. Conversely, prediction of symptomatic infection is low.

Systematic Review and Critical Evaluation of Quality of Clinical Practice Guidelines on Nutrition in Pregnancy.

Objective: To report the quality and clinical heterogeneity of the published clinical practice guidelines (CPGs) on nutrition in pregnancy. Methods: MEDLINE, Embase, Scopus, and ISI Web of Science databases were searched. The following aspects related to nutrition in pregnancy were addressed: specific requirements during pregnancy, description of a balanced diet, weight gain, prevention of food-borne, nutrition in peculiar sub-groups of women, and maternal or perinatal outcomes. The assessment of the risk of bias and quality assessment of the included CPGs were performed using "The Appraisal of Guidelines for REsearch and Evaluation (AGREE II)" tool divided in six quality domains: scope and purpose, stakeholder involvement, rigor of development, clarity of presentation, applicability, editorial independence. Mean ± standard deviation (SD) was used to summarize the scores across all the guidelines per domain. The quality of each guideline was computed using the scoring system proposed by Amer et al. A cut-off of >60% was sued to define a CGP as recommended. Results: Eighteen CPGs were included. There was a substantial heterogeneity in the recommended dose for vitamins, folic acid, and micronutrient intake during pregnancy among the different published CPGs. 27.8% (5/18) of the CPGs recommended a daily intake of folic acid of 200 mcg, 38.8% (7/18) 400 mcg, 16.7% (3/18) 600 mcg while the remaining CPGs suggested dose between 400 and 600−800 mc per day. Adequate maternal hydration was advocated in the large majority of included CPGs, but a specific amount of water intake was not reported in 83.3% (15/18) cases. There was also significant heterogeneity in various other aspects of nutrition recommendation among the different CPGs, including gestational weight gain (55.5%), prevention of food-borne diseases in pregnancy (72.2%), nutrition in particular groups of pregnant women (83.3%), maternal and perinatal outcomes (72.2%). The AGREE II standardized domain scores for the first overall assessment (OA1) had a mean of 65% but only half scored more than 60%. Conclusion: The published CPGs on nutrition in pregnancy show an overall good methodology, but also a substantial heterogeneity as regard as different major aspects on nutrition in pregnancy.

Trauma in pregnancy clinical practice guidelines: systematic review.

PURPOSE: To objectively evaluate the methodological quality and clinical heterogeneity robustness of the published clinical practice guidelines (CPGs) on the management of trauma in pregnancy. MATERIALS AND METHODS: Pubmed, Google Scholar, UpToDate, and Scopus Database were searched. The risk of bias and quality assessment of the included CPGs were performed using "The Appraisal Of Guidelines for Research and Evaluation (AGREE II)" tool. The following points relating to the management of trauma during pregnancy were addressed: quality of evidence assessment, classification of recommendations, main causes of trauma in pregnancy, importance of correct use of seat belts, ultrasound scans and/or pregnancy test in every female of reproductive age, description of physiological changes in pregnancy, classification in primary and secondary survey, primary survey based on ABCD Approach, fetus viable based on the weeks, radiographic studies for maternal evaluation, duration of fetal monitoring, use of anti-D immunoglobulin in rhesus-D-negative pregnant trauma patients, description of dose of RhD-Ig, the way to define gestational age if it was undetermined, descriptions of obstetrical complications, use of tetanus vaccination, and timing to perimortem cesarean section (CS). RESULTS: Six CPGs were included. Quality of evidence assessment was described in 16.7% of CPGs (1/6), while it was not reported in 83.3% (5/6). Classification of recommendations was reported in 50% (3/3) of the CPGs. Motor vehicle crash was reported as the main cause of trauma in pregnancy in all the CPGs included in the present review, despite that the importance of a correct use of seat belts was described only in the 50% (3/6). Definition of fetal viability was also different among the included CPGs; in 50% (3/6) defined a fetus viable when it from 23 weeks, 33.3% (2/6) from 24 weeks, and 16.7% (1/6) from 20 weeks of gestation. Regarding the type of fetal monitoring, 33.3% (2/6) CPGs recommended CTG assessment at least every 4 h, 16.7% (1/6) at least every 6 h, 33.3% for 24 h if there are not reassuring signs and 16.7% (1/6) did not specify the duration of monitoring. Recommendations about the use of anti-D-immunoglobulin in rhesus-D-negative pregnant were also heterogeneous: 50% (3/6) of the CPGs suggested administration in all rhesus-D-negative pregnant women, 16.7% (1/6) only according to gestational age at trauma or in case of significant abdominal trauma, and 16.7% (1/6) only in case of positive Kleihauer test while 16.7% (1/6) did not specify it. Administration of tetanus vaccination was suggested in in 33.3% (2/6) of CPGs. Finally, there were different descriptions of timing to perimortem CS: 33.3% (2/6) of CPGs claims to do CS no later than 4 min, 50% (3/6) no later than 5 min, and 16.7% (1/6) does not describe timing for CS. The AGREE II standardized domain scores for the first overall assessment (OA1) had a mean of 69%. Only three CPGs scored more than 60% and revealed a consensus agreement between the reviewers on recommending the use of these CPGs. CONCLUSION: There is clinical heterogeneity in some of the most relevant aspects of the management of pregnant women with trauma. The findings from this systematic review highlight the need for up to date and shared guidelines promoted by the main body societies in order make management of pregnant women with trauma homogenous.

Assessment of pericallosal artery at 11-14 weeks of gestation: Cohort study and meta-analysis.

OBJECTIVES: To report the rate of visualization of the pericallosal artery (PCA) in the first trimester of pregnancy (11-14 weeks). METHODS: Prospective observational study of consecutive fetuses undergoing first trimester risk assessment for chromosomal anomalies. The presence of PCA was assessed in a midsagittal view of fetal brain using high-definition power Color Doppler. A normal course of the PCA was defined as the visualization of an artery emerging from the anterior cerebral artery running parallel the corpus callosum (CC). The reference standard was the visualization of CC and PCA between the 20 and 22 weeks of gestation. We also performed a systematic review and meta-analysis of the published literature. Multivariate logistic regression and random-effect meta-analyses of proportion were used to analyze the data. RESULTS: Cohort study: Five-hundred women were included. PCA was identified trans-abdominally or transvaginally at 11-14 weeks of gestation in 98.8% (95% CI 97.4-99.6: 494/500); of the four cases of PCA not identified one had a diagnosis of complete agenesis of the corpus callosum during the anomaly scan which was confirmed at birth. Systematic review of the published literature: Six studies (1093 fetuses, including the present series) were included. The PCA was detected at the 11-14 weeks scan and confirmed to co-exist with a normal CC at time of the anomaly scan in 96.9% (95% CI 93.8-99.0); 20.6% (95% CI 5.7-41.7) of fetuses with no clear identification of the PCA at the 11-14 weeks scan had a normal appearance of the CC at the time of anomaly scan. CONCLUSION: Prenatal ultrasonography has a high diagnostic accuracy in detecting PCA in the first trimester. Visualization of the PCA at the time of 11-14 scan is highly specific for the presence of a normal CC later in pregnancy.

Role of balloon tamponade during cesarean section in women with placenta previa: a systematic review and meta-analysis.

INTRODUCTION: To explore the role of balloon tamponade insertion in pregnancies complicated by placenta previa. EVIDENCE ACQUISITION: Medline, Embase and ClinicalTrials.gov databases were searched electronically on October 17. Inclusion criteria were women with placenta previa undergoing, compared to those not undergoing, balloon tamponade insertion at the time of the cesarean section (CS). The outcomes observed were total, intra- and post-operative estimated blood loss (EBL), need for blood transfusion, admission to intensive care unit (ICU), hysterectomy and additional surgical or medical procedures to achieve hemostasis. Results were reported as pooled odd ratios (OR) or mean difference (MD) according to the outcome investigated. EVIDENCE SYNTHESIS: Four studies (593 women) were included. Total EBL was significantly lower in women undergoing balloon tamponade insertion during CS compared to controls (MD: -556.3, 95% CI -496 to -617.0, P=0.001). Likewise, women undergoing balloon tamponade insertion had significantly lower intra- (MD: -699.8, 95% CI -766.1 to -633.5, P=0.001) and post-operative (MD: -1162 mL (95% CI -1211.1 to -1134.4, P<0.001) compared to women who did undergo such procedure. Furthermore, women undergoing balloon tamponade insertion had a significantly lower risk of requiring additional surgical (OR: 0.16, 95% CI 0.1-0.5, I2=0%; P=0.001) or medical (OR: 0.02, 95% CI 0.003-0.1, I2=0; P=0.001) procedures to achieve hemostasis. Conversely, there was no significant difference in either the need for blood transfusion (P=0.071), admission to ICU (P=0.459) or need for hysterectomy (P=0.312) between women undergoing, compared to those not undergoing, balloon tamponade insertion during CS for placenta previa. CONCLUSIONS: Elective balloon tamponade insertion at the time of CS for placenta previa seems to be associated with a lower EBL and a reduced risk of additional medical and surgical procedures to control hemostasis. Large and adequately powered randomized controlled trials are needed to validate these results and introduce elective balloon tamponade insertion at the time of CS for placenta previa in clinical practice.

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.