Relationship between placenta location and resolution of second trimester placenta previa

A meta-analysis of obstetric and neonatal outcomes in patients after treatment of hysteroscopic adhesiolysis

Introduction

Hysteroscopic adhesiolysis is widely performed in women with intrauterine adhesions. Small observational studies have reported the obstetric and neonatal outcomes, but studies with larger sample sizes are few. The aim of this study is to evaluate the obstetric and neonatal outcomes in women after hysteroscopic adhesiolysis.

Methods

We conducted a literature search in July 2022 using the PubMed, Embase, the Cochrane Library, and Web of Science databases, and finally, 32 studies (N = 3812) were included. We did a meta-analysis to estimate the prevalence of placenta-related disorders, including placenta previa, placental abruption, placenta accreta, placenta increta, and retained placenta. We also included other obstetric and neonatal outcomes like postpartum hemorrhage, ectopic pregnancy, oligohydramnios, gestational hypertension, gestational diabetes mellitus, and intrauterine growth restriction. The results were presented as odds ratios (ORs) with 95% confidence intervals (CIs) in studies with a control group, but otherwise as prevalence (%) with 95% confidence intervals (CIs).

Results

The overall pregnancy and live birth rates were 58.97% and 45.56%, respectively. The prevalence of placenta previa differed in pregnant women who underwent hysteroscopic adhesiolysis compared with those who did not (OR, 3.27; 95% CI, 1.28-8.36). In studies without a comparative group, the pooled rate of placenta accreta was 7% (95% CI, 4-11) in 20 studies; placenta increta was 1% (95% CI, 0-4) in 5 studies; a retained placenta was 11% (95% CI, 5-24) in 5 studies; postpartum hemorrhage was 12% (95% CI, 8-18) in 12 studies; ectopic pregnancy was 1% (95% CI, 0-2) in 13 studies; oligohydramnios was 3% (95% CI, 1-6) in 3 studies; intrauterine growth restriction was 3% (95% CI, 1-8) in 3 studies; gestational hypertension was 5% (95% CI, 2-11) in 4 studies; and diabetes mellitus was 4% (95% CI, 2-7) in 3 studies.

Discussion

Due to the paucity of good quality comparative data, the question of whether there is an increased prevalence of obstetric and neonatal complications in women after hysteroscopic adhesiolysis compared with the general population remains unanswered. The findings from this review will provide a basis for more well-designed studies in the future.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=364021, identifier [CRD42022364021].

A Study of Clinical Characteristics, Demographic Characteristics, and Fetomaternal Outcomes in Cases of Placenta Previa: An Experience of a Tertiary Care Center

Background This study aimed to determine the demographic and clinical characteristics of pregnant women presenting with placenta previa and study the risk factors for the development of placenta previa, management strategies of associated complications, and maternal and perinatal outcomes. Methodology This prospective, observational study was conducted in the Department of Obstetrics and Gynaecology at Dr. S.N. Medical College, Umaid Hospital, Jodhpur, Rajasthan, India from May to October 2019. All patients with placenta previa were studied based on clinical presentation, management, and fetal and maternal outcomes. Results A total of 10,041 patients delivered during the study period. Of these, 61 were diagnosed with either minor placenta previa (placental edge within 2 cm, not covering the internal os) or major placenta previa (placental edge reaching or overlapping the internal os) for an incidence of 0.6%. The majority of the cases (65.57%) were in the age group of 20-29 years. Among the cases of placenta previa, 13.11% had previous cesarean sections, and 9.83% underwent previous dilatation and curettage (D & C) procedures. Moreover, 78.68% of the cases had ultrasound findings of the placenta partially or completely covering the os. Most patients were delivered by cesarean section (96.7%), and only 3.27% were delivered by vaginal delivery. Intensive care unit admission was required in 14.75% of the cases. The most common maternal complications observed were antepartum and postpartum hemorrhage, transfusion of blood and blood products, and long hospital stays. The preterm delivery rate was 62.30%, and 37.70% were term deliveries. Almost half of the babies (49.18%) were born with a birth weight of ≥2.5 kg, and 50.81% were in the low-birth-weight category. Apgar scores >7 at five minutes were observed in 85.3% of cases. Neonatal intensive care unit (NICU) admissions were 39.34%, and most babies recovered and shifted to the mother's side. The incidence of maternal mortality was 1.63%, and perinatal mortality was 9.83%. Conclusions The incidence of placenta previa was comparable to that reported in previous studies. Prevalence was more among younger women residing in rural areas who were unaware of regular antenatal check-ups. The main presenting symptom was painless vaginal bleeding, and ultrasonography was the most common diagnostic modality. Antepartum and postpartum hemorrhage was the most dreadful obstetric complications in cases of placenta previa, which affected maternal and fetal outcomes. Preterm and low birth weight were the main reason for NICU admissions. A team-based approach is required in the management of placenta previa cases.

Follow-up ultrasound in second-trimester low-positioned anterior and posterior placentae: prospective cohort study

OBJECTIVES

The majority of cases of placenta previa or a low-lying placenta in the second trimester will have a normal placental position in the third trimester. The aim of this study was to assess the accuracy of the distance between the placenta and the internal os of the cervix (IOD) in the second trimester for the prediction of third-trimester low-positioned placenta, and to define a cut-off value at which all cases of third-trimester low-positioned placenta are identified.

METHODS

This was a prospective cohort study including women undergoing a transvaginal ultrasound examination between 18 and 24 weeks' gestation who had a low-positioned placenta, defined as an IOD of < 20 mm. Low-positioned placenta included placenta previa, defined as a placenta covering the internal os of the cervix, and a low-lying placenta, defined as a placenta lying near to (within 20 mm) but not overlying the internal os. All women were re-evaluated in the third trimester. Relative risks for a low-positioned placenta in the third trimester were calculated for women with placenta previa vs a low-lying placenta, posterior vs anterior placenta and positive vs negative history of Cesarean section. Multilevel likelihood ratios for ranges of IOD in the prediction of a low-positioned placenta in the third trimester were calculated separately for anteriorly and posteriorly located placentae. Corresponding receiver-operating-characteristics curves were constructed.

RESULTS

In total, 958 women were included in the study. In the second trimester, placentae were more frequently located on the posterior side (62.0%) than on the anterior side (38.0%). In the third trimester, 48/958 (5.0%) placentae persisted as a low-positioned placenta. Women with placenta previa in the second trimester had a higher risk of a low-positioned placenta in the third trimester than did those with a low-lying placenta in the second trimester (37/181 (20.4%) vs 11/777 (1.4%); relative risk (RR), 17.9 (95% CI, 8.9-36.0)). Women with a posterior placenta had a higher risk of a low-positioned placenta in the third trimester than did those with an anterior placenta (38/594 (6.4%) vs 10/364 (2.7%); RR, 2.4 (95% CI, 1.2-4.9)), as did women with a history of Cesarean section compared with those without such a history (14/105 (13.3%) vs 34/853 (4.0%); RR, 3.7 (95% CI, 1.9-7.2)). The cut-off value of IOD in the second trimester to identify all cases of an abnormally located placenta in the third trimester was 15.5 mm for posteriorly located placentae, while for anteriorly located placentae the IOD cut-off was lower, namely -4.5 mm, representing a 4.5-mm overlap of the placental edge over the internal os of the cervix.

CONCLUSIONS

With incorporation of a safety margin of 5 mm and ensuring that all women with placenta previa undergo a follow-up scan, we recommend lowering the IOD cut-off value for follow-up in cases of an anterior low-positioned placenta from 20 to 5 mm, which would decrease the number of unnecessary follow-up ultrasound examinations without missing any high-risk women. © 2019 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.