Diagnosis and management of placenta previa and low placental implantation

Value of early pregnancy ultrasound combined with ultrasound score in the evaluation of placenta accreta in scar uterus: A retrospective cohort study

The objective of this study is to investigate the value of early pregnancy ultrasound combined with ultrasound score (USS) for the evaluation of placenta accreta (PA) in scar uteri. Thirty cases of PA in scar uteri diagnosed by ultrasound at our hospital between June 2021 and June 2022 were selected retrospectively (observation group). In addition, 30 patients had placenta attached to the anterior wall of the uterus and covered the internal orifice of the cervix; however, no PA was selected in the same period (control group). The results of surgical pathology and ultrasound examination in the first trimester of pregnancy (11-14 weeks of pregnancy, fetal top hip length 4.5-8.4 cm) were analyzed. Ultrasonic image characteristics of the 2 groups were scored using an ultrasonic scoring scale. The ultrasonic signs and ultrasonic scores of the 2 groups were analyzed. The diagnostic value of ultrasound and USS for PA in the scarred uterus alone and in combination was analyzed based on the gold standard of surgical and pathological results. The rich blood flow signal at the junction of the uterine serosa and bladder, the rate of blood flow in the cavity of the placental parenchyma, the thinning rate of the myometrium after placenta, and the abnormal rate of the low echo area after placenta in the observation group were significantly higher than those in the control group (P < .05). The USS of the observation group was significantly higher than that of the control group (P < .05). The sensitivity (93.33%) and accuracy (95.00%) of the combined examinations were significantly higher than those of ultrasound (70.00% and 83.33%, respectively) (P < .05). The sensitivity and accuracy of combined examination were slightly higher than those of USS examination (83.33% and 90.00%), but the difference was not statistically significant (P > .05). There was no significant difference between the specificity of combined examination (93.33%) and ultrasound (96.67%) and USS (96.67%) (P > .05). Early pregnancy ultrasound and USS evaluation have high application value in the diagnosis and evaluation of early scar uterine PA. The combination of the 2 methods can further improve the sensitivity and accuracy of diagnosis.

Low lying placenta: natural course, clinical data, complications and a new model for early prediction of persistency

OBJECTIVE

To define the natural course and complications, and develop a model for predicting persistency when low-lying placenta (LLP) is detected early in pregnancy.

METHODS

This retrospective cohort study included women with LLP detected during an early anatomic scan performed at 13-16 weeks gestation. Additional transvaginal ultrasound exams were assessed for resolution at 22-24 weeks and 36-39 weeks. Patients were categorized as: Group 1-LLP resolved by the second-trimester scan, Group 2-LLP resolved by the third trimester, or Group 3-LLP persisted to delivery. Clinical and laboratory parameters, as well as maternal and neonatal complications, were compared. A linear support vector machine classification was used to define a prediction model for persistent LLP.

RESULTS

Among 236 pregnancies with LLP, 189 (80%) resolved by 22-24 weeks, 25 (10.5%) resolved by 36-39 weeks and 22 (9.5%) persisted until delivery. Second trimester hCG levels were higher the longer the LLP persisted (0.8 ± 0.7MoM vs. 1.13 + 0.4 MoM vs. 1.7 ± 1.5 MoM, adjusted p = .03, respectively) and cervical length (mm) was shorter (first trimester: 4.3 ± 0.7 vs. 4.1 ± 0.5 vs. 3.6 ± 1; adjusted p = .008; Second trimester: 4.4 ± 0.1 vs. 4.1 ± 1.2 vs. 3.8 ± 0.8; adjusted p = .02). The predictive accuracy of the linear support vector machine classification model, calculated based on these parameters, was 90.3%.

CONCLUSIONS

Persistent LLP has unique clinical characteristics and more complications compared to cases that resolved. Persistency can be predicted with 90.3% accuracy, as early as the beginning of the second trimester by using a linear support vector machine classification model.

Trial of Labor Compared With Elective Cesarean Delivery for Low-Lying Placenta

OBJECTIVE

To compare outcomes of women with low-lying placenta by planned mode of delivery and distance from the internal os distance.

METHODS

Six tertiary maternity hospitals in France participated in this retrospective multicenter study of births from 2007-2012. Women with low-lying placenta , defined as an internal os distance of 20 mm or less, who gave birth after 35 weeks of gestation were included and classified in the planned trial-of-labor or elective cesarean delivery groups. The primary endpoint was severe postpartum hemorrhage (PPH) defined as blood loss exceeding 1,000 mL. Secondary outcomes were composite variables of severe maternal and neonatal morbidity. We used multivariable logistic regression and propensity scores to compare outcomes by planned mode of delivery.

RESULTS

Among 128,233 births during the study period, 171 (0.13%) women had low-lying placenta: 70 (40.9%) in the trial-of-labor group and 101 (59.1%) who underwent elective cesarean delivery. The rate of severe PPH was 22.9% (16/70, 95% CI 13.7-34.4) for the trial-of-labor group and 23.0% (23/101, 95% CI 15.2-32.5) for the cesarean delivery group ( P =.9); severe maternal and neonatal morbidity rates were likewise similar (2.9% vs 2.0% [ P =.7] and 12.9% vs 9.9% [ P =.5], respectively). Trial-of-labor was not significantly associated with a higher rate of severe PPH after multivariable logistic regression and propensity score-weighted analysis (adjusted odds ratio [aOR] 1.42, 95% CI 0.62-3.24 [ P =.4]; and aOR 1.34, 95% CI 0.53-3.38 [ P =.5], respectively). The vaginal delivery rate in the trial-of-labor group was 50.0% (19/38) in those with an internal os distance of 11-20 mm and 18.5% (5/27) in those with a distance of 1-10 mm.

CONCLUSION

Our results support a policy of offering a trial of labor to women with low-lying placenta after 35 weeks of gestation and an internal os distance of 11-20 mm. An internal os distance of 1-10 mm reduces the likelihood of vaginal birth considerably, compared with 11-20 mm, but without increasing the incidence of severe PPH or severe maternal morbidity.

Clinical Utility of the Prenatal Ultrasound Score of the Placenta Combined with Magnetic Resonance Imaging in Diagnosis of Placenta Accreta during the Second and Third Trimester of Pregnancy

Objective. The aim is to explore the clinical utility of the prenatal ultrasound score of the placenta combined with magnetic resonance imaging (MRI) in diagnosis of placenta accreta during the second and third trimester of pregnancy. Materials and Methods. A total of 108 pregnant women with suspected placenta accreta treated in Wuhan Hankou Hospital and Yantaishan Hospital of Yantai from January 2019 to January 2022 were retrospectively analyzed, the enrolled pregnant women received MRI examination because of suspected results of ultrasonic diagnosis, and by taking pathologic findings as the gold standard, the diagnostic efficacy of the ultrasound score, MRI, and their combination to placenta accreta during the second and third trimester of pregnancy was analyzed, and the diagnostic sensitivity, specificity, the positive predictive value, and the negative predictive value of these diagnostic modalities were evaluated. Results. Among 108 patients with suspected placenta accreta, 75 with pathologically confirmed placenta accreta were included in the accreta group, and 33 without placenta accreta were included in the non-accreta group; no statistical between-group differences in the patients’ age, gestational weeks, educational degree, and other general data were observed ( $P>0.05$ ), but the history of cesarean section, history of induced abortion, and incidence rate of placenta praevia were significantly higher in the accreta group than in the non-accreta group ( $P<0.05$ ); the ultrasound score was significantly higher in the accreta group than in the non-accreta group ( $P<0.05$ ); the incidence rates of signs of “placental heterogeneity” and “bulge of lower segment of the uterus and local thickening of the placenta” were obviously higher in the accreta group than in the non-accreta group ( $P<0.05$ ); according to the comparison with pathologic findings, the accuracy rate, sensitivity, specificity, the positive predictive value, and the negative predictive value of combined diagnosis were significantly higher than those of single application of the ultrasound score and MRI diagnosis ( $P<0.05$ ); and ROC analysis found that the area under the curve of combined diagnosis was obviously larger than that of the ultrasound score and MRI diagnosis ( $P<0.05$ ). Conclusion. A combining prenatal ultrasound score of the placenta with MRI plays an important role in the diagnosis of placenta accreta during the second and third trimester of pregnancy, which can further improve the diagnostic accuracy rate of placenta accreta and provide significant guidance in preventing high-risk complications during the perinatal period.

Deep Learning Algorithm-Based Ultrasound Image Information in Diagnosis and Treatment of Pernicious Placenta Previa

This study was to explore the value of the deep dictionary learning algorithm in constructing a B ultrasound scoring system and exploring its application in the clinical diagnosis and treatment of pernicious placenta previa (PPP). 60 patients with PPP were divided into a low-risk group (severe, implantable) and high-risk group (adhesive, penetrating) according to their clinical characteristics, B ultrasound imaging characteristics, and postpartum pathological examination results. Under PPP ultrasonic image information using the deep learning algorithm, the B ultrasound image diagnostic scoring system was established to predict the depth of various types of placenta accreta. The results showed that the cut-off values of severe, implantable, adhesive, and penetrating types were <2.3, 2.3-6.5, 6.5-9, and ≥9 points, respectively; there were significant differences in the termination of pregnancy and neonatal birth weight between the two groups (P < 0.05); the positive predictive value, negative predictive value, and false positive rate of ultrasound images based on the deep dictionary learning algorithm for PPP were 95.33%, 94.89%, and 3.56%, respectively. Thus, the ultrasound image diagnostic scoring system based on the deep learning algorithm has an important predictive role for PPP, which can provide a more targeted diagnosis and treatment plan for patients in clinical practice and improve the prediction and treatment efficiency.

A case of successful pregnancy in a septate uterus after discharge of decidual tissue in the second trimester

In pregnant patients with a divided uterine cavity, the decidual tissue on the nonpregnant side may be discharged prior to the delivery of the fetus. The pregnancy can continue if the uterine contractions and vaginal bleeding are controlled and the fetus is not in distress.