Preeclampsia (PE) is a major cause of maternal and perinatal morbidity and mortality. The only fundamental treatment for PE is the termination of pregnancy. Therefore, not only severe maternal complications but also perinatal complications due to immaturity of the infant associated with early delivery are serious issues. The treatment and prevention of preterm onset preeclampsia (POPE) are challenging. In 2017, the ASPRE trial showed that a low oral dose of aspirin administered to POPE high-risk women in early pregnancy reduced POPE by 62%. A prediction algorithm at 11–13 weeks of gestation identifies POPE with 75% sensitivity when the false positive rate is set at 10%. New biomarkers to increase the accuracy of the prediction model for POPE high-risk women in early pregnancy are needed. In this review, we focused on non-coding RNAs (ncRNAs) as potential biomarkers for the prediction of POPE. Highly expressed ncRNAs in the placenta in early pregnancy may play crucial roles in placentation. Furthermore, placenta-specific ncRNAs have been detected in maternal blood. In this review, we summarized ncRNAs that were highly expressed in the primary human placenta in early pregnancy. We also presented highly expressed ncRNAs in the placenta that were associated with or predictive of the development of PE in an expression analysis of maternal blood during the first trimester of pregnancy. These previous studies showed that the chromosome 19 microRNA (miRNA) -derived miRNAs (e.g., miR-517-5p, miR-518b, and miR-520h), the hypoxia-inducible miRNA (miR-210), and long non-coding RNA H19, were not only highly expressed in the early placenta but were also significantly up-regulated in the blood at early gestation in pregnant women who later developed PE. These maternal circulating ncRNAs in early pregnancy are expected to be possible biomarkers for POPE.

The invasion of extravillous trophoblast (EVT) cells into the maternal decidua, which plays a crucial role in the establishment of a successful pregnancy, is highly orchestrated by a complex array of regulatory mechanisms. Non-coding RNAs (ncRNAs) that fine-tune gene expression at epigenetic, transcriptional, and post-transcriptional levels are involved in the regulatory mechanisms of EVT cell invasion. However, little is known about the characteristic features of EVT-associated ncRNAs. To elucidate the gene expression profiles of both coding and non-coding transcripts (i.e., mRNAs, long non-coding RNAs (lncRNAs), and microRNAs (miRNAs)) expressed in EVT cells, we performed RNA sequencing analysis of EVT cells isolated from first-trimester placentae. RNA sequencing analysis demonstrated that the lncRNA H19 and its derived miRNA miR-675-5p were enriched in EVT cells. Although miR-675-5p acts as a placental/trophoblast growth suppressor, there is little information on the involvement of miR-675-5p in trophoblast cell invasion. Next, we evaluated a possible role of miR-675-5p in EVT cell invasion using the EVT cell lines HTR-8/SVneo and HChEpC1b; overexpression of miR-675-5p significantly promoted the invasion of both EVT cell lines. The transcription factor gene GATA2 was shown to be a target of miR-675-5p; moreover, small interfering RNA-mediated GATA2 knockdown significantly promoted cell invasion. Furthermore, we identified MMP13 and MMP14 as downstream effectors of miR-675-5p/GATA2-dependent EVT cell invasion. These findings suggest that miR-675-5p-mediated GATA2 inhibition accelerates EVT cell invasion by upregulating matrix metalloproteinases.

Introduction: Placental abruption is a serious complication, especially when accompanied by intrauterine fetal death. The optimal delivery route for placental abruption with intrauterine fetal death for reducing maternal complications is still unclear. In this study we aimed to compare the maternal outcomes between cesarean delivery and vaginal delivery in women with placental abruption with intrauterine fetal death.Material and methods: Using the Japan Society of Obstetrics and Gynecology nationwide perinatal registry database, we identified pregnant women with placental abruption with intrauterine fetal death between 2013 and 2019. The following women were excluded: those with multiple pregnancies, placenta previa, placenta accreta spectrum, amniotic fluid embolism, or whose delivery route was missing data. The association between delivery routes (cesarean delivery and vaginal delivery) and the maternal outcome was examined using a linear regression model with inverse probability weighting. The primary outcome was the amount of bleeding during delivery. Missing data were imputed using multiple imputation.Results: The number of women with placental abruption with intrauterine fetal death was 1218/1601932 (0.076%). Of 1134 women analyzed, 608 (53.6%) underwent cesarean delivery. Bleeding during delivery (median [interquartile range]) was 1650.00 (950.00–2450.00) (mL) and 1171.00 (500.00–2196.50) (mL) in cesarean and vaginal delivery, respectively. Bleeding during delivery (mL) was significantly greater in cesarean delivery than in vaginal delivery (regression coefficient, 1086.39; 95% confidence interval, 130.96–2041.81; p = 0.026). Maternal death and uterine rupture occurred in four (0.4%) and five (0.4%) women, respectively. The four maternal deaths were noted in the vaginal delivery group.Conclusions: Bleeding during delivery was significantly greater in cesarean delivery than that in vaginal delivery in women with placental abruption with intrauterine fetal death. However, severe complications, including maternal death and uterine rupture, occurred in vaginal delivery‐related cases. The management of women with placental abruption with intrauterine fetal death should be cautious regardless of the delivery route.

Pregnancy following adenomyomectomy is challenging because uterine rupture or placenta accreta spectrum (PAS) is more likely to occur; however, optimal management has not yet been established. We herein present a case of uterine rupture with placenta percreta in a pregnant woman who underwent adenomyomectomy twice before pregnancy. Magnetic resonance imaging (MRI) was performed in the second trimester and imminent uterine rupture concomitant with PAS was suspected. The patient was immediately admitted to hospital for careful management. Although failed tocolysis forced delivery at 29 weeks of gestation, managed hospitalization allowed cesarean hysterectomy to be performed uneventfully. Extensive PAS was proven pathologically in the removed uterus. Pregnancies following multiple adenomyomectomies are considered to be high-risk. Therefore, a sufficient explanation of the risks associated with future pregnancies is needed, particularly following second adenomyomectomy.

Objectives. The aims of this study were to clarify the following: (1) how often does prolonged pregnancy >= 34 weeks occur in patients with emergent cerclage without progesterone and (2) the risk factors preventing such pregnancy continuation. Materials and Methods. This retrospective observational study was performed using medical records of patients for whom emergent cerclage had been performed between April 2006 and December 2018 in our institute. Results. Emergent cerclage was performed in 123 patients (median age: 34, interquartile range: 31-36). Primiparous patients numbered 44 (36%). A history of spontaneous preterm birth (SPTB) was present in 30 (24%). The median presurgical cervical length (CL) was 16 (8-21) mm at surgery. Of the 123, 20 (16%) were delivered at 33 + 6 weeks or less (<34 weeks). We conducted logistic regression analysis of the risk factors of SPTBs <34 weeks after cerclage. Three risk factors were identified that increased the risk of SPTB <34 weeks: presurgical CL 0 mm (odds ratio (OR): 5.30; 95% confidence interval (CI): 1.58-17.7), a history of SPTB (OR: 4.65; 95% CI: 1.38-15.7), and the presence of sludge (OR: 4.14; 95% CI: 1.20-14.3). Conclusion. Three risk factors predicted SPTB <34 weeks after emergency cerclage without progesterone administration: unmeasurable CL (CL 0 mm), a history of SPTB, and the presence of sludge on ultrasound. SPTB <34 weeks occurred after emergency cerclage in 16% of patients, being comparable with the recent data with progesterone.