Obstetrical outcomes of pregnant women 50 years and older compared to those aged 45-49 years: A systematic review and meta-analysis.

AIM: In this review, We compared clinical characteristics of pregnant women aged 50 and older with those aged 45-49. Pregnant women ≥45 years are strongly associated with pregnancy-related complications, such as cesarean section rate, gestational hypertension, gestational diabetes mellitus, and preterm birth. Although pregnant women ≥50 years are considered more high-risk, differences in pregnancy outcomes between those over 45 and 50 years of age are unclear. METHODS: Our source strategy included using PubMed, the Cochrane Central Register of Controlled Trials, and Web of Science databases to include studies published between January 1, 2010 and September 30, 2022. The study population was pregnant women 50 years and older; the control group was pregnant women aged 45-49 years. Primary outcomes were cesarean section, gestational hypertension, gestational diabetes mellitus, and preterm birth. The secondary outcomes were small-for-gestational age, 5-min Apgar score < 7, neonatal intensive care unit admission (as neonatal outcomes), nulliparity, assisted reproductive technology (ART), and multifetal pregnancy (as maternal backgrounds). RESULTS: The incidence of cesarean section, gestational hypertension, and preterm delivery was significantly higher in those 50 years and older; however, significant differences disappeared when pooled analyses were limited to singleton pregnancies. ART was significantly more likely to be used for conception of pregnant women ≥50 years. Infants of women ≥50 years were more likely to be admitted to NICUs. CONCLUSIONS: The differences in outcomes between the two groups are obviously influenced by multiple pregnancies, therefore, reproductive medicine specialists should aim for singleton pregnancies in ART.

Unexpected uterine body placenta accreta spectrum with placenta previa in a subsequent pregnancy after uterine artery embolization: a case report.

BACKGROUND: A subsequent pregnancy after uterine artery embolization (UAE) raises several concerns, one of which is placenta accreta spectrum (PAS). Placenta previa is the strongest risk factor for PAS, which is most likely to occur in the lower uterine segment. PAS without placenta previa (i.e., uterine body PAS) is considered relatively rare. CASE PRESENTATION: A 35-year-old woman, gravida 2 para 1, had undergone UAE for postpartum hemorrhage due to uterine atony after vaginal delivery in her previous pregnancy. She developed placenta previa during her subsequent pregnancy and was therefore evaluated for PAS in the lower uterine segment. On the basis of examination findings, we considered PAS to be unlikely. During cesarean section, we found that the placenta was not detached from the uterine body, and the patient was determined to have uterine body PAS. Ultimately, a hysterectomy was performed. CONCLUSIONS: PAS can occur in a subsequent pregnancy after UAE. When a subsequent pregnancy after UAE is accompanied by placenta previa, it is important to maintain a high index of suspicion of uterine body PAS without being misled by the presence of placenta previa.

Massive ascites due to lupus peritonitis in a patient with pre-eclampsia and systemic lupus erythematosus: a case report.

BACKGROUND: Patients with systemic lupus erythematosus (SLE) are associated with pre-eclampsia. Pre-eclampsia can have systemic manifestations, such as ascites. Lupus peritonitis, a rare condition in patients with SLE, can also cause ascites. CASE PRESENTATION: A 31-year-old woman, primigravida, with SLE had a blood pressure of 170/110 mmHg and proteinuria at 29 weeks of gestation. She was diagnosed with pre-eclampsia. Her blood pressure was stabilized by an antihypertensive drug. At 30 weeks of gestation, a cesarean section was performed for maternal safety because of decreased urine output and massive ascites. Postoperatively, re-accumulation of ascites was observed. On the fourth postoperative day, ascites (approximately 3 L) was discharged from the cesarean section wound. A decrease in serum complement concentrations was observed, and she was diagnosed as having lupus peritonitis. The steroid dose was increased and she recovered well thereafter. CONCLUSIONS: Ascites occurs in pre-eclampsia and SLE, but determining which of these conditions causes ascites can be difficult. However, careful observation is necessary because of the differences in treatment of these two conditions.

Fetal biometric and Doppler measurements following abdominal radical trachelectomy in the second trimester of the pregnancy.

BACKGROUND: Our previous study demonstrated the safety and effectiveness of abdominal radical trachelectomy during pregnancy but did not focus on the fetus. This study aimed to clarify the influence of abdominal radical trachelectomy performed during pregnancy on the fetus. METHODS: Eight cervical cancer patients who underwent abdominal radical trachelectomy at our hospital between February 2013 and August 2020 were enrolled in this study. To assess the peri- and postoperative influence on the fetus, we performed fetal heart monitoring at 30-min intervals during abdominal radical trachelectomy and calculated the estimated fetal body weight and resistance indexes of the middle cerebral artery and umbilical artery from postsurgery until delivery. RESULTS: Four out of eight patients had preterm birth due to chorioamnionitis in one case and consideration of the recurrent risk of cervical cancer in three cases. Fetal heart monitoring during abdominal radical trachelectomy revealed deceleration just once in one case but no abnormal findings in the other cases. In all cases, the fetal growth after abdominal radical trachelectomy was normal until delivery. No abnormal Doppler findings were detected in the middle cerebral artery or umbilical artery. CONCLUSION: Our findings clarified that abdominal radical trachelectomy performed for the treatment of early-stage cervical cancer during pregnancy has no obvious influence on fetal growth. Next, it is necessary to evaluate the growth and development of children delivered from mothers who have undergone abdominal radical trachelectomy during pregnancy.

Successful repeated uterine artery embolization in postpartum hemorrhage with disseminated intravascular coagulation: a case report and literature review.

BACKGROUND: Postpartum hemorrhage (PPH) is a potentially fatal condition requiring urgent and appropriate intervention. Uterine artery embolization (UAE) has a high hemostatic capacity for PPH, but it may fail. Disseminated intravascular coagulation (DIC) has been reported as a risk factor associated with the failure of UAE. CASE PRESENTATION: A 37-year-old primigravida with dichorionic diamniotic twins and placenta previa underwent cesarean section. The blood loss during surgery was 4950 mL. Hemostasis was achieved using an intrauterine balloon tamponade device. However, she lost a further 2400 mL of blood 5 h after surgery. We embolized both uterine arteries using gelatin sponges and confirmed hemostasis. She was suffering from DIC and received ample blood transfusions. However, a further 1300 mL of blood was lost 18 h after surgery and we performed repeated UAE, with complete recanalization of the uterine arteries on both sides and re-embolization with gelatin sponges. Her DIC was treated successfully by blood transfusions at this time, and she showed no further bleeding after the repeated UAE. CONCLUSIONS: DIC is a risk factor for the failure of UAE. Repeated UAE may be effective after sufficient improvement of the hematological status in patients with PPH and DIC.

PET/MR imaging for the evaluation of cervical cancer during pregnancy.

BACKGROUND: Malignancy during pregnancy is increasing, and the most common type of malignancy is uterine cervical cancer. When planning the treatment of cervical cancer, it is important to look for signs of metastasis before surgery, especially metastasis to the lymph nodes. In this report, we assessed the diagnostic value of positron emission tomography/magnetic resonance imaging (PET/MRI) for evaluating cervical cancer propagation before surgery, with a focus on pregnant women. CASE PRESENTATION: 18F Fluorodeoxyglucose (FDG)-PET/MRI was performed in seven pregnant cervical cancer patients (28-34 years old) at 9-18 gestational weeks. In case #5, a second PET/MRI was performed at 24 gestational weeks. Of seven FDG-PET/MRI examination series in six cases (cases #1-6), FDG-PET/MR imaging could detect cervical tumors with abnormal FDG accumulation; these tumors were confirmed with a standardized uptake value max (SUV max) titer of 4.5-16. A second PET/MRI examination in case #5 revealed the same SUV max titer as the first examination. In these six imaging series (cases #1-5), there were no signs of cancer metastasis to the parametrium and lymph nodes. However, in case #6, abnormal FDG accumulation in the left parametrial lymph nodes was also detectable. Pathological examination showed lymph node metastasis in case #6. In case #7, PET/MRI could not detect any abnormal FDG accumulation in the cervix and other sites. Cone biopsy demonstrated only micro-invasive squamous cell carcinoma. After treatment for cervical cancer, all seven patients have had no recurrence of disease within the follow-up period (2.8-5.6 years), and their children have developed appropriately. CONCLUSION: PET/MRI is an effective imaging tool to evaluate cervical cancer progression in pregnancy.

Classification of factors involved in nonreportable results of noninvasive prenatal testing (NIPT) and prediction of success rate of second NIPT.

OBJECTIVE: To evaluate the reasons for nonreportable cell-free DNA (cfDNA) results in noninvasive prenatal testing (NIPT), we retrospectively studied maternal characteristics and other details associated with the results. METHODS: A multicenter retrospective cohort study in pregnant women undergoing NIPT by massively parallel sequencing (MPS) with failed cfDNA tests was performed between April 2013 and March 2017. The women's data and MPS results were analyzed in terms of maternal characteristics, test performance, fetal fraction (FF), z scores, anticoagulation therapy, and other details of the nonreportable cases. RESULTS: Overall, 110 (0.32%) of 34 626 pregnant women had nonreportable cfDNA test results after an initial blood sampling; 22 (20.0%) cases had a low FF (<4%), and 18 (16.4%) cases including those with a maternal malignancy, were found to have altered genomic profile. Approximately half of the cases with nonreportable results had borderline z score. Among the women with nonreportable results because of altered genomic profile, the success rate of retesting using a second blood sampling was relatively low (25.0%-33.3%). Thirteen (11.8%) of the women with nonreportable results had required hypodermic heparin injection. CONCLUSIONS: The classification of nonreportable results using cfDNA analysis is important to provide women with precise information and to reduce anxiety during pregnancy.

Treatment for patients with recurrent fetal losses positive for anti-cardiolipin beta2 glycoprotein I antibody using Sairei-to (Chai-ling-tang) and low-dose aspirin.

AIM: Recently, it is widely recognized that positivity for anti-phospholipid antibodies is a causative factor for a range of reproductive failures. Anti-cardiolipin beta2 glycoprotein I antibody (anti-CL-beta2-GPI) is a representative anti-phospholipid antibody, which strongly correlates with the development of thrombotic events and diversity of adverse pregnancies. In this series, we aimed to elucidate effective treatment for patients with recurrent fetal losses positive for anti-CL-beta2-GPI using Japanese-modified Chinese herbal medicine. METHODS: Twenty-one patients with recurrent fetal losses who were positive for anti-CL-beta2-GPI were treated with the Japanese-modified Chinese herbal medicine, Sairei-to (Chai-ling-tang), and low-dose aspirin with or without adrenal corticosteroid hormone. Of the 21 patients, the value of anti-CL-beta2-GPI ranged from 1.9 to 3.4 in 10 patients, and it was over 3.5 in 11 patients. RESULTS: Of the 21 patients treated with the current protocol, the pregnancy successfully continued in 17 patients (success rate: 81.0%). Of the four patients who showed repeated abortion, chromosome abnormality of chorionic villi was observed in two; thus, the success rate would be 89.5% (17 of 19 cases) on excluding these cases from the evaluation. CONCLUSION: The efficacy of the current treatment adopting the modified Japanese version of the Chinese herbal medicine Sairei-to for patients with recurrent fetal losses positive for anti-CL-beta2-GPI was indicated.

The Safety and Effectiveness of Abdominal Radical Trachelectomy for Early-Stage Cervical Cancer During Pregnancy.

OBJECTIVES: Cervical cancer is one of the most frequently diagnosed cancers in pregnancy. Our aim was to evaluate the safety and efficacy of abdominal radical trachelectomy (ART) for pregnant women with early-stage cervical cancer who strongly desire to preserve their pregnancies. METHODS/MATERIALS: A retrospective observational study was performed for stage IB1 cervical cancer patients who underwent ART or radical hysterectomy (RH) at our hospital between February 2013 and June 2017. We compared differences in perioperative findings and oncologic outcomes among ART during pregnancy (ART-DP), ART, and RH groups. RESULTS: A total of 38 patients were included in this analysis. Six, 10, and 22 patients were assigned to the ART-DP, ART, and RH groups, respectively. There were no significant differences in the distribution of pathological TNM classifications, histology, tumor size, stromal invasion, and lymph-vascular space invasion among the 3 groups. The patients in the ART-DP group were younger than those in the RH group (P = 0.014). The ART-DP group was associated with more blood loss and prolonged surgery compared with the RH group (P = 0.017 and P = 0.014). The number of total lymph nodes in the ART-DP group was lower than that in the RH group (P = 0.036). However, there were no significant differences in age, surgical time, blood loss, or lymph node count between the ART-DP and ART groups. There were no significant differences in progression-free and overall survival times among the 3 groups, and no recurrence was observed in the ART-DP group. CONCLUSIONS: Abdominal radical trachelectomy may be a tolerable treatment option for pregnant women with early-stage cervical cancer who strongly desire a baby.

Effectiveness of fetal cardiac screening for congenital heart disease using a combination of the four-chamber view and three-vessel view during the second trimester scan.

AIM: We aimed to assess the accuracy and effectiveness of fetal cardiac screening for congenital heart disease (CHD) during the second trimester by general obstetricians in a non-selected population. METHODS: In this multicenter, prospective cohort study of fetal cardiac screening, four-chamber and three-vessel views were recorded by obstetricians at 18-21 gestational weeks (GW). A total of 3005 fetuses that were scheduled for delivery at our institution were included. RESULTS: Thirty-seven newborns were born with CHD (1.2%). On excluding 23 cases of ventricular septal defects, the prenatal detection rate of CHD was 42.8%. Although six cases (75.0%) of severe structural abnormality were diagnosed prenatally, the prenatal detection rate of valvular abnormalities was 0%. CONCLUSION: One-point ultrasound screening of the fetal heart using a combination of four-chamber and three-vessel views at 18-21 GW by general obstetricians in a non-selected population may be useful for detecting severe structural abnormalities but not valvular abnormalities. However, this limitation may be improved by conducting another fetal cardiac screening at approximately 30 GW along with the routine use of color Doppler.

Current status of non-invasive prenatal testing in Japan.

AIM: The purpose of this study was to report the 3-year experience of a nationwide demonstration project to introduce non-invasive prenatal testing (NIPT) of maternal plasma for aneuploidy, and review the current status of NIPT in Japan. METHODS: Tests were conducted to detect aneuploidy in high-risk pregnant women, and adequate genetic counseling was provided. The clinical data, test results, and pregnancy outcomes were recorded. We discuss the problems of NIPT on the basis of published reports and meta-analyses. RESULTS: From April 2013 to March 2016, 30 613 tests were conducted at 55 medical sites participating in a multicenter clinical study. Among the 30 613 women tested, 554 were positive (1.81%) and 30 021 were negative (98.1%) for aneuploidy. Of the 289, 128, and 44 women who tested positive for trisomies 21, 18, and 13, respectively, and underwent definitive testing, 279 (96.5%), 106 (82.8%), and 28 (63.6%) were determined to have a true-positive result. For the 13 481 women with negative result and whose progress could be traced, two had a false-negative result (0.02%). The tests were performed on the condition that a standard level of genetic counseling be provided at hospitals. CONCLUSION: Here, we report on the 3-year nationwide experience with NIPT in Japan. It is important to establish a genetic counseling system to enable women to make informed decisions regarding prenatal testing. Moreover, a welfare system is warranted to support women who decide to give birth to and raise children with chromosomal diseases.

A survey on awareness of genetic counseling for non-invasive prenatal testing: the first year experience in Japan.

The purpose of this study is to summarize the results from a survey on awareness of genetic counseling for pregnant women who wish to receive non-invasive prenatal testing (NIPT) in Japan. As a component of a clinical study by the Japan NIPT Consortium, genetic counseling was conducted for women who wished to receive NIPT, and a questionnaire concerning both NIPT and genetic counseling was given twice: once after pre-test counseling and again when test results were reported. The responses of 7292 women were analyzed. They expressed high satisfaction with the genetic counseling system of the NIPT Consortium (94%). The number of respondents who indicated that genetic counseling is necessary for NIPT increased over time. Furthermore, they highly valued genetic counseling provided by skilled clinicians, such as clinical geneticists or genetic counselors. The vast majority (90%) responded that there was sufficient opportunity to consider the test ahead of time. Meanwhile, women who received positive test results had a poor opinion and expressed a low-degree satisfaction. We confirmed that the pre-test genetic counseling that we conducted creates an opportunity for pregnant women to sufficiently consider prenatal testing, promotes its understanding and has possibilities to effectively facilitate informed decision making after adequate consideration. A more careful and thorough approach is considered to be necessary for women who received positive test results.

Prior uterine bleeding is associated with low visibility due to discolored amniotic fluid on fetoscopic laser photocoagulation.

AIM: To investigate the association between uterine bleeding preceding fetoscopic laser photocoagulation (FLP) and the presence of discolored amniotic fluid that impedes FLP. METHODS: A retrospective review of all multiple gestations requiring FLP at the present institution was conducted. The rate of low visibility because of discolored amniotic fluid at the beginning of FLP was compared between patients with and without a history of uterine bleeding, defined as either genital bleeding or ultrasonographically detected subchorionic hematoma. RESULTS: The prevalence of low visibility because of discolored amniotic fluid was 4.5% (seven in 156 patients). Two of the seven cases of low visibility resulted in double fetal death. The incidence of low visibility was significantly higher in the group with uterine bleeding before surgery compared with that without bleeding (28.6% vs 0.74%, P < 0.001). CONCLUSIONS: Patients with a history of uterine bleeding prior to FLP may encounter more technical difficulties owing to discolored amniotic fluid during FLP.

Fetal Hydrops Associated With 47,XXX: A Case Report and Literature Review.

This report aims to investigate the association between 47,XXX and fetal hydrops by examining a clinical case and performing a comprehensive review of the relevant literature. A 34-year-old Japanese woman, gravida 2, para 1, was diagnosed with fetal hydrops at 27 weeks' gestation. Prenatal testing revealed a 47,XXX karyotype. Interventions included thoracocentesis and a thoracoamniotic shunt. A cesarean delivery was performed at 34 weeks and the female neonate initially had respiratory challenges. After 69 days in the neonatal intensive care unit, the infant was discharged in stable condition, and the 47,XXX karyotype was confirmed. This case may add evidence suggesting an association between 47,XXX and fetal hydrops. Chromosomal abnormalities are causes of fetal hydrops, but its association with 47,XXX remains unclear. Providing comprehensive information on this condition to couples is crucial, and considering the inclusion of fetal hydrops in the list of associated conditions might be advisable.

Pregnancy Following Spontaneous Healing of Uterine Rupture: A Case Report and Experience of Management.

Uterine rupture can heal naturally without the need for surgical intervention. However, reports on subsequent pregnancies are limited. A 27-year-old woman, gravida 2, para 1, visited our institution at seven weeks of gestation. She had previously experienced uterine rupture with postpartum hemorrhage, which had healed naturally without surgical intervention. We thoroughly explained the perinatal complications associated with the subsequent pregnancy, particularly the risk of uterine rupture recurrence, and managed her pregnancy progress carefully. We took great care to ensure that signs of a silent rupture were not missed on imaging examinations. A planned cesarean delivery was performed at 35 weeks of gestation, resulting in an uneventful pregnancy outcome. We report the details of our management of a subsequent pregnancy in a woman who had previously experienced uterine rupture with natural healing. Our findings may serve to support healthcare providers managing similar cases.

A nonsynonymous variant of IL1A is associated with endometriosis in Japanese population.

Our previous genome-wide association study has demonstrated that single-nucleotide polymorphisms (SNPs) located in intronic and downstream regions of IL1A (interleukin 1α) were associated with the risk of endometriosis. These SNPs on the genome-wide association study platform could be only surrogates for the true causal variant. Thus, we resequenced all the exons of IL1A in 377 patients with endometriosis and 457 healthy controls. We detected seven rare variants (minor allele frequency <0.01) and four common variants. All the rare variants were not associated with endometriosis. The four common variants (rs17561, rs1304037, rs2856836 and rs3783553) in IL1A were significantly associated with endometriosis (P=0.0024, 0.0024, 0.0014 and 0.0061, respectively). All the four SNPs were within a linkage disequilibrium block. Among them, only rs17561 was nonsynonymous (p.A114S), which has been reported to be associated with susceptibility to ovarian cancer. Taken together, we examined association between rs17561 and endometriosis in an independent validation data set (524 patients and 533 healthy controls) replicating significant association (P=4.0 × 10(-5); odds ratio (OR), 1.91; 95% confidence interval (CI), 1.41-2.61). Meta-analysis by combining results from the two stages strengthened the evidence of association (P=2.5 × 10(-7); OR, 1.90; 95% CI, 1.49-2.43). Our findings demonstrated that the nonsynonymous variant of IL1A might confer genetic susceptibility to endometriosis in Japanese population.

Increased incidence of brain metastases in BRCA1-related ovarian cancers.

AIM: Brain metastasis from ovarian cancer is a very rare phenomenon. BRCA1-related ovarian cancers show specific pathobiological profiles, advanced stage, and sensitivity to chemotherapeutic agents. However, no clear relationship to any known metastatic behavior has yet been found, so we examined the BRCA1 mutation and expression profiles in ovarian cancer cases with brain metastases. MATERIAL AND METHODS: We examined our clinical records of 340 ovarian cancer cases from 1983 to 2007 to ascertain cases with brain metastases. In the molecular genetic analyses, we performed loss of heterozygosity (LOH), direct sequence and immunohistochemical staining analysis of BRCA1. RESULTS: We ascertained seven cases with brain metastases in 340 ovarian cancer cases (7/340=2.1%). Among the seven cases, three cases had ovarian and/or breast cancer patients in third-degree relatives. We detected four LOH-positive cases and a germline mutation of BRCA1 in two of the four cases. Furthermore, the remaining two cases showed absent staining of the BRCA1 protein. Therefore, four of seven cases with brain metastases were considered BRCA1-related ovarian cancers (4/7=57.1%). All four of the cases were serous adenocarcinoma. CONCLUSION: Our results suggest that the loss of BRCA1 function may be involved in the phenomenon of brain metastasis from ovarian cancer. Further molecular biologic analyses will be required for a better understanding of this rare phenomenon.

Pregnancy outcomes at maternal age over 45 years: a systematic review and meta-analysis.

OBJECTIVE: This study aimed to identify trends in pregnancy outcomes, especially delivery mode, among pregnant patients older than 45 years. DATA SOURCES: A literature search was performed using PubMed, Web of Science, and the Cochrane Central Register of Controlled Trials for studies published between January 1, 2010, and June 30, 2022. STUDY ELIGIBILITY CRITERIA: The primary outcomes were cesarean delivery and assisted delivery. The secondary outcomes were preeclampsia, gestational diabetes mellitus, placenta previa, placental abruption, postpartum hemorrhage, and preterm birth. The inclusion criteria were studies examining the relationship between older age pregnancy and pregnancy outcomes, studies that compared pregnancy outcomes at maternal age ≥45 years and <45 years, and at least one of the primary and secondary pregnancy outcomes were included. METHODS: Study screening was performed after duplicates were identified and removed. The quality of each study and publication bias were assessed. Forest plots and I2 statistics were calculated for each study outcome for each group. The main analysis was a random-effects analysis. The inverse variance method was used to integrate the results if studies had an adjusted analysis. RESULTS: Among 4209 studies initially retrieved, 24 were included in this review. All studies were retrospective, observational studies. Pregnant patients aged ≥45 years had a significantly higher cesarean delivery rate (odds ratio, 2.87; 95% confidence interval, 2.50-3.30; I2=97%) than those aged <45 years. However, the emergency cesarean delivery rate was lower in older pregnant patients (odds ratio, 0.61; 95% confidence interval, 0.47-0.79; I2=79%). Pregnancy in older individuals was associated with a lower assisted delivery rate than pregnancy in younger individuals (odds ratio, 0.85; 95% confidence interval, 0.75-0.97; I2=48%). Preeclampsia, gestational diabetes mellitus, placenta previa, placental abruption, postpartum hemorrhage, and preterm birth were more likely to occur in pregnant patients aged ≥45 years than in those aged <45 years. Adjusted pooled analyses showed trends similar to those in the unadjusted pooled analyses. CONCLUSION: Adverse pregnancy outcomes, typically cesarean delivery, were more likely to occur in older (≥45 years) pregnant patients than in younger pregnant patients. However, the assisted delivery rate was lower in older pregnant patients.

Comparison of maternal outcomes and clinical characteristics of prenatally vs nonprenatally diagnosed placenta accreta spectrum: a systematic review and meta-analysis.

OBJECTIVE: This study aimed to compare maternal outcomes of prenatally and nonprenatally diagnosed placenta accreta spectrum. DATA SOURCES: A systematic literature search was performed in PubMed, the Cochrane database, and Web of Science until November 28, 2022. STUDY ELIGIBILITY CRITERIA: Studies comparing the clinical presentation of prenatally and nonprenatally diagnosed placenta accreta spectrum were included. The primary outcomes were emergent cesarean delivery, hysterectomy, blood loss volume, number of transfused blood product units, urological injury, coagulopathy, reoperation, intensive care unit admission, and maternal death. In addition, the pooled mean values for blood loss volume and the number of transfused blood product units were calculated. The secondary outcomes included maternal age, gestational age at birth, nulliparity, previous cesarean delivery, previous uterine procedure, assisted reproductive technology, placenta increta and percreta, and placenta previa. METHODS: Study screening was performed after duplicates were identified and removed. The quality of each study and the publication bias were assessed. Forest plots and I2 statistics were calculated for each study outcome for each group. The main analysis was a random-effects analysis. RESULTS: Overall, 415 abstracts and 157 full-text studies were evaluated. Moreover, 31 studies were analyzed. Prenatally diagnosed placenta accreta spectrum was associated with a significantly lower rate of emergency cesarean delivery (odds ratio, 0.37; 95% confidence interval, 0.21-0.67), higher hysterectomy rate (odds ratio, 1.98; 95% confidence interval, 1.02-3.83), lower blood loss volume (mean difference, -0.65; 95% confidence interval, -1.17 to -0.13), and lower number of transfused red blood cell units (mean difference, -1.96; 95% confidence interval, -3.25 to -0.68) compared with nonprenatally diagnosed placenta accreta spectrum. The pooled mean values for blood loss volume and the number of transfused blood product units tended to be lower in the prenatally diagnosed placenta accreta spectrum groups than in the nonprenatally diagnosed placenta accreta spectrum groups. Nulliparity (odds ratio, 0.14; 95% confidence interval, 0.10-0.20), previous cesarean delivery (odds ratio, 6.81; 95% confidence interval, 4.12-11.25), assisted reproductive technology (odds ratio, 0.19; 95% confidence interval, 0.06-0.61), placenta increta and percreta (odds ratio, 3.97; 95% confidence interval, 2.24-7.03), and placenta previa (odds ratio, 6.81; 95% confidence interval, 4.12-11.25) showed statistical significance. No significant difference was found for the other outcomes. CONCLUSION: Despite its severity, the positive effect of prenatally diagnosed placenta accreta spectrum on outcomes underscores the necessity of a prenatal diagnosis. In addition, the pooled mean values provide a preoperative preparation guideline.