Blood loss in low-lying placenta: placental edge to cervical internal os distance of less vs. more than 2 cm

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.

Pregnancy and Delivery Outcomes in Women With Persistent Versus Resolved Low-Lying Placenta in the Late Third Trimester

OBJECTIVES

The safest mode of delivery in low-lying placenta is debatable. Little is known about outcomes in low-lying placenta resolved during the late third trimester. We compare outcomes of women with persistent versus resolved low-lying placenta.

METHODS

A retrospective analysis on a prospective cohort of women with low-lying placenta confirmed at 28-30 weeks sonography (01/2009 to 03/2018). Women were followed up serially every 2 to 3 weeks until delivery to assess the placental edge-to-internal os distance (IOD), and included if scan was performed within 28 days before delivery.

RESULTS

There were 86 women: in 21 the low-lying placenta resolved, whereas in 65 persisted (n = 15 IOD 1-10 mm, n = 50 IOD 11-20 mm). Antepartum bleeding associated with higher rates of urgent cesarean delivery in 1-10 mm (P = .041) but not in 11-20 mm (P = 1.000) and >20 mm (P = .333). Among women with IOD >10 mm allowed to labor, vaginal delivery occurred in 76.7% (11-20 mm) and 94.1% (>20 mm) (P = .155), with no difference according to parity (70% and 80% in multiparas, P = .696; 60% and 72.7% in nulliparas, P = .698). Severe PPH (P = .922) and hemoglobin drop (P = .109) were similar among groups. Women with IOD 11-20 mm and >20 mm and vaginal delivery bled less than women with similarly located placenta and cesarean delivery (P = .009 and P = .048).

CONCLUSIONS

Women with IOD >10 mm have high chances of deliver vaginally with no further increase of their hemorrhagic risk. Success of vaginal delivery is independent of parity and antepartum bleeding. Labor should be managed in an adequate hospital setting.

A new surgical technique "cervical internal os plasty" in cesarean delivery for placenta previa accreta: A case-control study

Placenta previa accreta is an obstetrical complication that severely affects the heath of the fetus and the mother due to massive hemorrhage during pregnancy. This study reported a new suture technique called "cervical internal os plasty" to control obstetrical hemorrhage in cesarean delivery for patients with placenta previa accreta and retrospectively evaluated the safety and effectiveness of the new technique.From January 2012 to May 2018, we collected 56 patients with this new suture technique, which repaired the damaged weak area with bleeding from the placental attachment site in the lower uterine segment, and restored the damaged anatomic internal os of the cervix. Meanwhile, we compared it with 60 cases with other conservative methods described by other obstetricians with the same qualifications. The perioperative outcomes (blood loss, blood transfusion, operative time, other applied medical technology, and so on) between the 2 groups were recorded in this report.There were no significant differences between 2 groups among age, gravidity, parity, gestational age, and previous dilatation and curettage techniques (P > .05). Of the patients with placenta previa accrete, 77.6% (90/116) had previous dilatation and curettage. The comparison between study group and control group on the rate of postpartum hemorrhage, blood transfusion, and mean operative time, average hospitalization days after cesarean delivery, expenses was not statistically significant (P > .05). Compared with the control group, other applied supplementary techniques (including uterine tamponade, pelvic arterial embolization, or emergency hysterectomy) for the bleeding from the the placental attachment site is fewer significantly in the study group. No operative accident and hemorrhea-related complication occurred in the 2 groups.Cervical internal os plasty is useful in patients with placenta previa accreta due to its simplicity, utility, and effectivity as well as its capacity for preserving fertility.

Diagnosis and management of placenta previa and low placental implantation

Objective: To evaluate the migration of low-placental implantation (LPI) during the third trimester of pregnancy and its effect on delivery and post-partum hemorrhage.Methods: We conducted a retrospective study at a level 3 maternity center including all cases of placenta previa (PP) and LPI between 1998 and 2014. The distance (d) between cervical internal os (CIO) and placental edge (PE) were measured by vaginal ultrasonography in the third trimester of pregnancy at 32 and 3 weeks after. We analyzed CIO-PE distance, volume of post-partum hemorrhage, delivery decision, and mode of delivery using Kruskall-Wallis test.Results: In total, 319 patients presented with PP or LPI. All complete PP (121) and 90.6% (58 of 64) of the placentas less than 1 cm from the CIO did not migrate. Among the 138 placentas with an initial CIO-PE d greater than 1 cm, only 17 (12.3%) did not migrate above 2 cm. The patients for whom the decision to perform a cesarean section (C-section) was retained and realized had a CIO-PE d significantly lower than those who delivered vaginally (p < .001). The patients who delivered by C-section had a lower CIO-PE d when an emergency C-section was performed, specifically for hemorrhage (p < .001). The mean volume of hemorrhage was significantly higher for patients with a CIO-PE d less than 2 cm.Conclusion: Complete PP and the majority of the placentas less than 1 cm from the CIO did not migrate. Above 1 cm, the majority of the placentas migrated three to four weeks later. For the placentas less than 1 cm from the CIO, a significant risk of hemorrhage at delivery was observed. Thus, prophylactic cesarean section is required for CIO-PE distances <1 cm. For distances between 1 and 2 cm, the volume of blood loss tends to be more important than for distances >3 cm without statistical significance. A vaginal delivery could be tried after information of patients.

Resolution of a Low-Lying Placenta and Placenta Previa Diagnosed at the Midtrimester Anatomy Scan

OBJECTIVES

To identify the incidence and resolution rates of a low-lying placenta or placenta previa and to assess the optimal time to perform follow-up ultrasonography (US) to assess for resolution.

METHODS

We conducted a retrospective cohort study of women with a diagnosis of a low-lying placenta or placenta previa at routine anatomic screening. Follow-up US examinations were reviewed to estimate the proportion of women who had resolution. A Kaplan-Meier survival curve was generated to estimate the median time to resolution. The distance of the placental edge from the internal cervical os was used to categorize the placenta as previa or low-lying (0.1-10 or ≥ 10-20 mm). A time-to-event analysis was used to estimate predictive factors and the time to resolution by distance from the os.

RESULTS

A total of 1663 (8.7%) women had a diagnosis of a low-lying placenta or placenta previa. The cumulative resolution for women who completed 1 or more additional US examinations was 91.9% (95% confidence interval, 90.2%-93.3%). The median time to resolution was 10 (interquartile range [IQR], 7-13) weeks. The distance from the internal cervical os was known for 658 (51.0%) women. The probability of resolution was inversely proportional to the distance from the internal os: 99.5% (≥10-20 mm), 95.4% (0.1-10 mm), and 72.3% (placenta previa; P < .001). The median times to resolution were 9 (IQR, 7-12) weeks for 10 to 20 mm, 10 (IQR, 7-13) weeks for 0.1 to 10 mm, and 12 (IQR, 9-15) weeks for placenta previa (P = .0003, log rank test).

CONCLUSIONS

A low-lying placenta or placenta previa diagnosed at the midtrimester anatomy survey resolves in most patients. Resolution is near universal in patients with an initial distance from the internal os of 10 mm or greater.

Prevalence of antepartum hemorrhage in women with placenta previa: a systematic review and meta-analysis

Antepartum hemorrhage (APH) is an important cause of perinatal mortality and maternal morbidity in pregnant women with placenta previa in the world. However, the epidemiological characteristics are not completely understood. We performed an initial systematic review and meta-analysis to assess the prevalence of APH in pregnant women with placenta previa. It was totally performed following the Preferred Reporting Items for Systematic reviews and Meta-Analysis statement. PubMed, Elsevier Science Direct, and the Cochrane Library were searched before April 2016. A meta-analysis with a random-effects model based on a proportions approach was performed to determine the prevalence. Stratified analyses, meta-regression method, and sensitivity analysis were utilized to analyze the heterogeneity. A total of 29 articles were included. The pooled overall prevalence of APH among pregnant women with placenta previa was 51.6% (95% CI 42.7-60.6) in a heterogeneous set of studies (I2 = 97.9). Correlation analysis found that there was a positive correlation between prevalence and percentage of multiparous (r = 0.534, P = 0.027) and a negative correlation between prevalence and survey year (r = -0.400, P = 0.031). In conclusion, the prevalence of APH was a high condition among pregnant women with placenta previa.

Fetal imaging: executive summary of a joint Eunice Kennedy Shriver National Institute of Child Health and Human Development, Society for Maternal-Fetal Medicine, American Institute of Ultrasound in Medicine, American College of Obstetricians and Gynecologists, American College of Radiology, Society for Pediatric Radiology, and Society of Radiologists in Ultrasound Fetal Imaging workshop

Given that practice variation exists in the frequency and performance of ultrasound and magnetic resonance imaging (MRI) in pregnancy, the Eunice Kennedy Shriver National Institute of Child Health and Human Development hosted a workshop to address indications for ultrasound and MRI in pregnancy, to discuss when and how often these studies should be performed, to consider recommendations for optimizing yield and cost effectiveness, and to identify research opportunities. This article is the executive summary of the workshop.

Fetal imaging: Executive summary of a Joint Eunice Kennedy Shriver National Institute of Child Health and Human Development, Society for Maternal-Fetal Medicine, American Institute of Ultrasound in Medicine, American College of Obstetricians and Gynecologists, American College of Radiology, Society for Pediatric Radiology, and Society of Radiologists in Ultrasound Fetal Imaging Workshop

Given that practice variation exists in the frequency and performance of ultrasound and magnetic resonance imaging in pregnancy, the Eunice Kennedy Shriver National Institute of Child Health and Human Development hosted a workshop to address indications for ultrasound and magnetic resonance imaging in pregnancy, to discuss when and how often these studies should be performed, to consider recommendations for optimizing yield and cost-effectiveness and to identify research opportunities. This article is the executive summary of the workshop.

Fetal imaging: executive summary of a joint Eunice Kennedy Shriver National Institute of Child Health and Human Development, Society for Maternal-Fetal Medicine, American Institute of Ultrasound in Medicine, American College of Obstetricians and Gynecologists, American College of Radiology, Society for Pediatric Radiology, and Society of Radiologists in Ultrasound Fetal Imaging Workshop

Given that practice variation exists in the frequency and performance of ultrasound and magnetic resonance imaging (MRI) in pregnancy, the Eunice Kennedy Shriver National Institute of Child Health and Human Development hosted a workshop to address indications for ultrasound and MRI in pregnancy, to discuss when and how often these studies should be performed, to consider recommendations for optimizing yield and cost effectiveness, and to identify research opportunities. This article is the executive summary of the workshop.

Toward consistent terminology of placental location

The diagnosis of placenta previa has shifted from clinical examination of the dilated cervix to sonographic assessment of the closed internal os, resulting in terminology confusion. If the cervix is closed, the distinction between a placental edge at the cervical margin and one partially covering the os is neither reliable nor clinically important. Cesarean delivery is recommended if the placenta reaches the cervical margin at time of delivery, and this entity may be grouped with placenta previa. Partial previa should probably be restricted to those with cervical dilatation. The terms marginal previa and low-lying placenta have been used interchangeably. However, if the placenta implants in the lower uterine segment but does not reach the cervix, low-lying placenta is preferred, and vaginal delivery may be achieved, depending on placental-os distance and presence of bleeding. Limited data suggest that if the placenta is within 2 cm of the os-low-lying placenta, cesarean delivery is performed for bleeding in one-third of cases.

Identifying regional variation in the prevalence of postpartum haemorrhage: a systematic review and meta-analysis

OBJECTIVE

To provide regional estimates of the prevalence of maternal haemorrhage and explore the effect of methodological differences between studies on any observed regional variation.

METHODS

We conducted a systematic review of the prevalence of maternal haemorrhage, defined as blood loss greater than or equal to 1) 500 ml or 2) 1000 ml in the antepartum, intrapartum or postpartum period. We obtained regional estimates of the prevalence of maternal and severe maternal haemorrhage by conducting meta-analyses and used meta-regression to explore potential sources of between-study heterogeneity.

FINDINGS

No studies reported the prevalence of antepartum haemorrhage (APH) according to our definitions. The prevalence of postpartum haemorrhage (PPH) (blood loss ≥500 ml) ranged from 7.2% in Oceania to 25.7% in Africa. The prevalence of severe PPH (blood loss ≥1000 ml) was highest in Africa at 5.1% and lowest in Asia at 1.9%. There was strong evidence of between-study heterogeneity in the prevalence of PPH and severe PPH in most regions. Meta-regression analyses suggested that region and method of measurement of blood loss influenced prevalence estimates for both PPH and severe PPH. The regional patterns changed after adjusting for the other predictors of PPH indicating that, compared with European women, Asian women have a lower prevalence of PPH.

CONCLUSIONS

We found evidence that Asian women have a very low prevalence of PPH compared with women in Europe. However, more reliable estimates will only be obtained with the standardisation of the measurement of PPH so that the data from different regions are comparable.