Cases Of Previa Research Articles

Prevalence of placenta previa among deliveries in Mainland China: A PRISMA-compliant systematic review and meta-analysis.

Placenta previa is characterized by the abnormal placenta overlying the endocervical os, and it is known as one of the most feared adverse maternal and fetal-neonatal complications in obstetrics. We aimed to obtain overall and regional estimates of placenta previa prevalence among deliveries in Mainland China. The research was performed a systematic review, following the Meta-analysis of observational studies in epidemiology (MOOSE) guidelines for systematic reviews of observational studies, and the preferred reporting items for systematic reviews and meta-analysis (PRISMA) statement for reporting systematic reviews and meta-analysis. Electronic databases were searched and included hospital-based studies that reported placenta previa prevalence in Mainland China. Random-effects meta-analyses were used to pool prevalence estimates of placenta previa. Meta-regression analyses were performed to explore sources of heterogeneity across the included studies. For exploring the geographical distributions of placenta previa, the ArcGIS software (Esri) was used to construct the map of prevalence. A total of 80 articles and 86 datasets (including 1,298,548 subjects and 14,199 placenta previa cases) from 1965 through 2015 were included. The pooled overall prevalence of placenta previa among deliveries was 1.24% (95% confidence interval [CI], 1.12-1.36) in Mainland China during 1965 to 2015. And, the trend in the prevalence of placenta previa was steady. The occurrence rate of placenta previa in the region groups Northeast, North, Northwest, Central China, East, South, and Southwest was 1.20%, 1.01%, 1.10%, 1.15%, 0.93%, 1.42%, and 2.01%, respectively. The prevalence map based on a geographic information system showed an unequal geographic distribution. The results showed that placenta previa is currently a high-burden disease in Mainland China. This review would be useful for the design of placenta previa planning and implementation adequate health care systems and treatment programs in Mainland China.

EP14.03: Ultrasound diagnosis and evaluation of the number of prior Caesarean deliveries as risk factor for placenta accreta in placenta previa cases

EP14.03: Ultrasound diagnosis and evaluation of the number of prior Caesarean deliveries as risk factor for placenta accreta in placenta previa cases

Vasa previa: diagnosis and management

Vasa previa is a rare condition that is associated with a high rate of fetal or neonatal death when not diagnosed antenatally. The majority of available studies are either small, do not include antepartum data, limited to single institutions, or are biased by inclusion of patients from registries and online vasa previa support groups. The purpose of this study was to investigate the diagnostic and management strategies for this potentially catastrophic entity and to describe further maternal and placental risk factors that may aid in the establishment of a screening protocol for vasa previa. This was a retrospective multicenter descriptive study that included all pregnancies that were complicated by vasa previa that delivered between January 1, 2000, and December 31, 2012. Nine maternal fetal medicine practices and the hospitals in which they practice participated in data collection of diagnosis, treatment, and maternal-neonatal outcomes. Sixty-eight pregnancies were identified that included the diagnosis of vasa previa or "possible vasa previa" either in the ultrasound record or in the hospital record at the time of delivery. Four cases (5.8%) appeared to resolve on repeat ultrasound examination. Fifteen of the 64 cases that were suspected of having vasa previa could not be verified or were not documented at delivery. Of the remaining 49 cases, where vasa previa was documented, 47 cases (96%) were diagnosed by ultrasound scanning antenatally. Known risk factors for vasa previa were present in 41 of 47 cases (87%). Of the 49 cases, 41 were delivered by planned cesarean delivery at a mean gestational age of 34.7 weeks, and 8 cases required emergent cesarean delivery at a mean gestational age of 34.6 weeks (range, 32.4-36.0 weeks gestation). Seven of these emergent cesarean deliveries had been diagnosed previously; 1 case had not. All of the emergent cesarean deliveries were for vaginal bleeding; 1 case was also for a concerning fetal heart rate, but only 1 of the known cases had a documented ruptured fetal vessel. None of these cases were found to have cervical shortening before the onset of bleeding. One of the undiagnosed cases resulted in a ruptured fetal vessel and a baby with no heart beat at birth who survived but had periventricular leukomalacia at 1 month of age with mild white-matter atrophy. Of the remaining neonates in this group, there were no deaths and no major complications beyond mild respiratory distress syndrome in 9 cases. There were no other major neonatal complications, which included no cases of periventricular leukomalacia, neonatal sepsis, necrotizing enterocolitis, or any grade of intraventricular hemorrhage in the confirmed cases of vasa previa. This study confirms most current recommendations that include risk-based ultrasound screening, early hospitalization at 30-34 weeks gestation, antenatal corticosteroids at 30-32 weeks gestation, and elective delivery at 33-34 weeks gestation. Thus, with these recommendations for current identification and management of vasa previa in this series of geographically diverse mostly private practice maternal fetal medicine practices, we have confirmed recent reports that show a dramatic improvement in neonatal survival and complications compared with earlier reports.

Plasenta previa ve akreta olgularında konservatif ve radikal cerrahi sonuçlarının değerlendirilmesi

Plasenta previa ve akreta olgularında konservatif ve radikal cerrahi sonuçlarının değerlendirilmesi

Plasenta previa ve akreta olgularında konservatif ve radikal cerrahi sonuçlarının değerlendirilmesi

Objective: To evaluate our 5-year clinical experience in the management of cases with placenta previa together with placental attachment anomalies and the activity of the hypogastric artery ligation (HAL) for the protection of uterus. Methods: The cases who had cesarean section and were established the diagnosis of placenta previa and accreta between 2009 and 2014 in the Department of Obstetrics and Gynecology, Faculty of Medicine, Mustafa Kemal University were evaluated retrospectively. The medical files of the patients were analyzed and their demographic characteristics, and surgical and conservative approaches were evaluated. Hysterectomy rates after cesarean section of the patients who did and did not undergo hypogastric artery ligation were compared. Results: In the evaluation of 67 placenta previa cases included in the study, 32 patients were applied post-cesarean hysterectomy, 40 patients were applied HAL, 12 patients were applied uterine sutures and 3 patients were applied Foley catheter. All of the patients who were applied uterine suture and Foley catheter were in the non-hysterectomy group. It was found that 27 (67.5%) of 40 patients who had HAL were applied post-cesarean hysterectomy and 5 of 27 patients who did not have HAL were applied post-cesarean hysterectomy, and there was statistically a significant difference between groups (p=0.001). In the pathology results of the patients who had hysterectomy, it was reported that 8 (25%) patients did not have accreta, 11 (34.4%) patients did not have increta, 10 (31.3%) patients did not have percreta and 3 (9.4%) patients did not have placental invasion. In terms of complications, it was found that 9 cases had bladder injury, one case had vaginal cuff hematoma and one case had disseminated intravascular coagulopathy. In neonatal outcomes, mean delivery week was 35.2±5.7, birth weight was 2674 g, 1-minute and 5-minute Apgar scores were 6.7 and 7.8, respectively. Fetal anomalies were observed in two newborns. Conclusion: In cases with placenta previa in company with placental attachment anomaly, conservative surgical approach can be an alternative method. However, organ protection activity of HAL in such cases is considered to be suspicious.

The Pattern of Blood Loss in Women With Placenta Previa and Accreta [57

OBJECTIVE: Placenta previa and accreta are important contributors to postpartum hemorrhage, a major cause of maternal morbidity. This study assessed patterns of blood loss for these conditions. METHODS: This analysis included women with placental implantation abnormalities with an estimated blood loss (EBL) greater than 1,000 mL at a tertiary care center between 2007 and 2013. EBL per unit of time was routinely collected and abstracted for analysis. Three distinct populations were examined: (1) Cases of suspected accreta without hysterectomy, classified as “BPMyo” because of the surgical pathology finding of “basal plate with myometrial fibers” upon examination of the placenta; (2) cases of previa without hysterectomy; and (3) cases of accreta with previa, confirmed after hysterectomy. RESULTS: Forty-four women (16 BPMyo; 16 previa; 12 accreta) met inclusion criteria. Mean age, BMI and gravidity did not differ between groups. Mean total EBL was significantly different (P< 0.01) with accreta cases averaging 2.85 L (standard deviation [SD] ±1.29) compared to 1.81 L for BPMyo (SD±0.69) and 1.72 L for previa (SD±0.44). Cumulative blood loss over time differed significantly (P< 0.01), as did maximum rates of blood loss (P< 0.01), with peaks of 2.71 L/hour for accreta (SD±2.38), 1.18 L/hour for BPMyo (SD±1.06) and 1.0 L/hour for previa (SD±0.77). CONCLUSION: Patients receiving a hysterectomy due to accreta have a significantly different total EBL, maximum rate of blood loss, and pattern of cumulative blood loss compared to those with previa or BPMyo alone. Awareness of these differences may help obstetricians better manage postpartum hemorrhage.

Systematic review of accuracy of ultrasound in the diagnosis of vasa previa.

Vasa previa is an obstetric complication in which the fetal blood vessels lie outside the chorionic plate in close proximity to the internal cervical os. In women with vasa previa, the risk of rupture of these vessels is increased, thus potentially causing fetal death or serious morbidity. Our objective was to assess the accuracy of ultrasound in the prenatal diagnosis of vasa previa. We searched MEDLINE, EMBASE, the Cochrane Library and PubMed for studies on vasa previa. Two reviewers independently selected studies on the accuracy of ultrasound in the diagnosis of vasa previa. The studies were scored on methodological quality using the Quality Assessment of Diagnostic Accuracy Studies tool (QUADAS-2). Data on sensitivity and specificity were subsequently extracted. The literature search revealed 583 articles, of which two prospective and six retrospective cohort studies were eligible for inclusion in the qualitative analysis. All studies documented methods suitable for the prenatal diagnosis of vasa previa. Four out of the eight studies used transvaginal ultrasound (TVS) for primary evaluation, while the remaining four studies used transabdominal ultrasound and performed a subsequent TVS when vasa previa was suspected. The QUADAS-2 tool reflected poor methodology in six of the eight included studies, and prenatal detection rates varied from 53% (10/19) to 100% (total of 442,633 patients, including 138 cases of vasa previa). In the two prospective studies (n = 33,795, including 11 cases of vasa previa), transvaginal color Doppler performed during the second trimester detected all cases of vasa previa (sensitivity, 100%) with a specificity of 99.0-99.8%. The accuracy of ultrasound in the diagnosis of vasa previa is high when performed transvaginally in combination with color Doppler.

First trimester maternal serum biochemical markers of aneuploidy in pregnancies with abnormally invasive placentation

To examine whether differences exist in routine first trimester maternal serum screening analyte measurements between normal pregnancies, placenta praevia and abnormally invasive placentation (AIP). Multidisciplinary audit. Associated university teaching hospital with 9000 annual deliveries. Five hundred and sixteen pregnancies in total, including 344 normal controls, 17 with AIP and 155 placenta praevia cases. Comparison of maternal serum free βhCG and PAPP-A MoMs distribution in pregnancies with abnormally invasive placentation, placenta praevia and normal controls, after correcting for known confounding factors between October 2005 and September 2013. Data from a previously published first trimester AIP and biochemistry study were combined with our study data and compared in the above way to complete the analysis. Differences in first trimester maternal serum PAPP-A and free βhCG in AIP, placenta praevia, and normal pregnancies. Median free βhCG MoM in the control group was 1.04, and 1.08 (P = 0.859) in the placenta praevia group compared with 0.81 in the AIP group (P = 0.06). Median PAPP-A MoM was 1.01 in the control group and 1.05 (P = 0.83) in praevia, compared with 1.22 in AIP cases (0.16). The combined AIP dataset gave an overall PAPP-A median MoM of 1.40, and free βhCG of 0.85. Both markers showed a significantly different distribution from controls (PAPP-A P = 0.002 and free βhCG P = 0.031). There may be differences between first trimester maternal serum biochemical markers between normal pregnancies and those complicated by abnormally invasive placentation. If upheld, this may provide useful information for the early identification of abnormally invasive placentation. More studies are required.

Descendent migration in vasa previa.

‘Placental migration’ involves the translocation of the placental site to the upper uterine segment in the second and third trimesters [1]. Since the uterine isthmus is usually closed during early pregnancy, subsequently opening with advancing gestation, this phenomenon is thought to strongly involve placental migration. Vasa previa is a condition in which the lower velamentous vessels are located over the region of the internal os. We hypothesized that the velamentous vessels in the lower uterine segment (low VCI) might migrate toward the uterine cervix, in opposition to the direction of migration of the placenta (descendent migration), as the amniotic bag expands toward the uterine cervix and opens the uterine isthmus, resulting in vasa previa. It was supposed that a diagnosis of vasa previa should be made after the opening of the uterine isthmus to ensure an accurate antenatal ultrasound diagnosis. To clarify our hypothesis, a prospective cohort study was conducted, in which the condition of the uterine cervix and isthmus and location of low VCIs were carefully observed using transvaginal ultrasound until delivery. The diagnosis of low VCI with vasa previa at 20 weeks of gestation was made in 12 patients (0.4 % of 2,923 total deliveries). Among eight cases of an opened uterine isthmus at 20 weeks of gestation, six cases of vasa previa and one case of low VCI without vasa previa were diagnosed. The findings in these cases were consistent until the time of delivery. The remaining case of placenta previa with low VCI at 20 weeks of gestation progressed to a low-lying placenta with vasa previa at delivery due to atrophy of the placenta around the internal os (Type II vasa previa). On the other hand, among the four patients with a closed uterine isthmus at 20 weeks of gestation, three were diagnosed with low VCI without vasa previa at delivery. However, in the remaining one case with a low VCI, migration of velamentous vessels toward the cervical os with opening of the isthmus resulting in vasa previa was observed during uterine contractions induced by a transvaginal ultrasound examination at 20 weeks of gestation. Figure 1 presents a transvaginal ultrasonographic picture of such descendent migration. Although velamentous vessels were not running on the uterine os before the opening of the uterine isthmus, the velamentous vessels on the amniotic membrane were descending toward the uterine isthmus with the expansion of the amniotic bag after the opening of the uterine isthmus was induced by uterine contractions. In conclusion, in contradiction to the concept of ascendant migration of the placenta, the velamentous vessels in the lower uterine segment occasionally migrated in the direction of the uterine cervix, resulting in vasa previa. However, the location of velamentous vessels was generally consistent until the time of delivery, after opening the uterine isthmus. This phenomenon suggests that the diagnosis of vasa previa should be made following the complete opening of the uterine isthmus. J. Hasegawa (&) H. Takita T. Arakaki A. Sekizawa Department of Obstetrics and Gynecology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8666, Japan e-mail: hasejun@oak.dti.ne.jp

Management of vasa previa during pregnancy.

In order to prevent fetal mortality due to vasa previa, it is necessary to obtain an antenatal diagnosis and perform elective cesarean section prior to membrane rupture. Under present circumstances, management strategies for vasa previa depend on each institutional policy. In our institution, patients are not routinely admitted, although precise outpatient management, including confirming the presence of uterine contractions and monitoring the cervical length, fetal growth and fetal heart rate, is provided for pregnant females with vasa previa. In the present report, we reviewed 21 cases of vasa previa managed at our hospital. Some 71% (15/21) of them were required inpatient management due to its complications, resulting in emergency delivery in about half of them. Therefore, our results suggest that only carefully selected asymptomatic patients may be successfully managed as outpatients.

Impact of warning bleeding on the cortisol level in the fetus and neonatal RDS/TTN in cases of placenta previa

Objective: The purpose of this study was to examine the levels of hormones in umbilical vein blood that affect the neonatal respiratory function in cases of placenta previa and to evaluate the impact of warning bleeding on the hormone levels and neonatal respiratory outcomes such as respiratory distress syndrome (RDS) and transient tachypnea of the newborn (TTN).Methods: We analyzed data obtained from 33 placenta previa cases without fetal or maternal complications at 36–38 weeks of gestation. We measured the levels of hormones such as cortisol, arginine vasopressin, epinephrine and norepinephrine in umbilical vein blood using ELISA.Results: Warning bleeding was found to be a significant factor protecting against neonatal RDS/TTN (p = 0.049). The cortisol levels in the umbilical vein were significantly higher in the cases of previa with warning bleeding than in those without warning bleeding (p = 0.020) and significantly higher in the no RDS/TTN cases than in the RDS/TTN cases (p = 0.040).Conclusions: Warning bleeding increases the cortisol level in cases of placenta previa. We suggest that genital bleeding may induce stress for both the mother and fetus, resulting in increased cortisol production, thus functioning as a protective factor against neonatal respiratory disorders.

The risk of placental abruption and placenta previa in pregnant women with chronic hepatitis B viral infection: A systematic review and meta-analysis

IntroductionSeveral epidemiological studies have found a positive association between chronic hepatitis B virus (CHB) infection and the risk of placental abruption and placenta previa, but various studies have reported conflicting findings. The objective was to systematically review the literature to determine a possible association between CHB infection and these two placental complications. MethodsWe conducted a computerized search in electronic database through March 1, 2014, supplemented with a manual search of reference lists, to identify original published research on placental abruption and placenta previa rates in women with CHB infection. Data were independently extracted, and relative risks were calculated. The meta-analysis was performed using Stata version 10.0 software. ResultsFive studies involving 9088 placenta previa cases were identified. No significant association between CHB infection and placenta previa was identified (OR = 0.98, 95% CI = 0.60–1.62). Five studies involving 15571 placental abruption cases were identified. No significant association between CHB infection and placental abruption was identified (OR = 1.42, 95% CI, 0.93–2.15). DiscussionThe immune response against the virus represents a key factor in determining infection outcomes. No observation of significant increased risk of the placental complications could be partially explained by the complex immune response during CHB infection. ConclusionsOur meta-analysis found no evidence of significant associations between CHB infection and increased risk of placental abruption as well as placenta previa. Further well-designed studies were warranted to assess any potential association between CHB infection and increased risk of placental abruption as well as placenta previa.

Is There an Association Between Placenta Previa and Serum Analytes?

INTRODUCTION: The objective of this study was to evaluate the association between maternal serum analytes and placenta previa. METHODS: Chart review of deliveries from 2004 to 2012 with two comparison groups: placenta previa without accreta and a control group. Patients in the control group were randomly selected from deliveries without placenta previa. Patients with previa were confirmed by third-trimester ultrasonography. Exclusion criteria were placenta previa with pathology-confirmed accreta, multiple gestations, fetal anomalies, or growth restriction. Primary outcomes were maternal serum analytes in the first trimester: pregnancy-associated plasma protein A and free β-human chorionic gonadotropin (β-hCG), and second trimester: α-fetoprotein), free β-hCG, unconjugated estriol, and inhibin. RESULTS: Twenty-six women with previa met inclusion criteria and 43 women in the control group. The groups did not differ with respect to maternal age, gravidity, or parity. Alpha-fetoprotein multiples of the median was significantly higher in women with previa cases than women in the control group (P<.005). Pregnancy-associated plasma protein A multiples of the median was higher (but was not statistically significant) in women with previa than in the women in the control group (P<.064). There were no differences between groups with respect to first-trimester free β-hCG, second-trimester free β-hCG, unconjugated estriol, or inhibin (Table 1). The following analytes were not available on all specimens: second-trimester free β-hCG, unconjugated estriol, and inhibin.CONCLUSIONS: In our women with placenta previa, maternal serum α-fetoprotein was significantly higher than in women in the control group. We also observed higher levels of pregnancy-associated plasma protein A in women with previa but this did not reach statistical significance. Prospective studies are needed to confirm these findings and determine the relationship with pregnancy outcome.

Ultrasonographic Study of Placenta Positioning and Its Significance in Parturition among Women in Delta State

Ultrasound is a useful adjunct to the physical examination, particularly in obstetrics patients. By ultrasonography we visualize the placenta position in-situ and describe various positioning of placenta in the uterus. The placenta is positioned at different sites in the uterus which can predict methods of parturition. The objective of this study is to investigate the different positions of placenta as seen in ultrasound scan and it's significant in parturition among women in Delta state. The study comprises of 150 women who registered for antenatal care at Eku Baptist Hospital Eku, Delta state, and have given birth in the Hospital. The pregnant women were examined with ultrasound scan which determined the positions of the placenta at the radiodiagnostic department. The different positions such as anterior, posterior, fundal and previa were recorded. The methods of deliveries were also taken note of in the pre-maternal labour forms in obstetrics/gynaecology department and health record office of the Hospital. Data were presented as mean and standard deviation; data were analysed using statistical package for social science (SPSS). The cases of previa were related to the type of delivery out of 28 cases of previa 18 women delivered by caesarean section and 10 had normal delivery. 10 out of all are previa type I, 7 are previa type II, and 11 are previa type III. All type III cases delivered through caesarean section.

Challenges in diagnosis of pseudo vasa previa.

Vasa previa is a rare but clinically important obstetrical complication that can be associated with a low-lying placenta or placenta previa. We aim to convey the challenges in diagnosing this condition by presenting 2 cases of pseudo vasa previa diagnosed antenatally as vasa previa using standard and color Doppler ultrasonography. Both patients were falsely diagnosed; only a low-lying placenta was revealed after delivery. These reports emphasize that accurate identification of vasa previa on cervical imaging is important for determining an appropriate treatment strategy.

Matrix metalloproteinase and its tissue inhibitors placental expression in placenta praevia

Background Uterus wall scarring is one of the key factors of placenta praevia (PP) development. Objective To study matrix metalloproteinase (MMP-2 and MMP-9) and its tissue inhibitors (TIMP-2 and TIMP-3) placental expression in placenta praevia cases in pregnancy with uterus scars. Materials and method Forty-four term placentas from cesarean section delivery were divided into 3 groups: PP without uterus scar (12 cases), PP with uterus scar (14 cases) and control group (14 cases). MMPs and TIMPs placental expression was studied immunohistochemically. Results All PP cases were characterized by significantly decreased MMP-2, TIMP-2, TIMP-3 and significantly elevated MMP-9 terminal villi syncytial and endothelial expression compared to control (p 0.05). PP cases with uterus scar were characterized by significantly lower MMPs and TIMPs decidual and extravillous trophoblastic expression compared to PP without scar (p Discussion This study has revealed that different patterns of MMPs and TIMPs placental expression could be a reflection of different pathogenic events in scarred uterus PP development.

Prophylactic bilateral internal iliac arteries balloon occlusion in 13 patients of pernicious placenta previa with placenta accreta

Objective To explore the efficacy of prophylactic bilateral internal iliac arteries balloon occlusion in treatment of women with pernicious placenta previa complicated with placenta accreta. Methods A retrospective analysis was conducted on 41 cases of pernicious placenta previa with placenta accreta admitted to Guangzhou Women and Children＇s Medical Centre from January 2010 to December 2012. The study group （n=13） underwent prophylactic bilateral internal iliac arteries balloon placement before cesarean section and occlusion after delivery. The control group （n= 28） received conventional haemostasis during cesarean section. The amount of blood loss and blood transfusion during the operation, the perioperative hemoglobin level, operation time and duration of hospitalization of the two groups were compared with t-test or Chi-square test. Results The volume of intraoperative hemorrhage of the study group was lower than of the control group [（1429±875） ml vs （4600±2090） ml, t= 6. 840, P=0. 000], the amount of intraoperative blood transfusion in the study group was also lower [（920±438） ml vs （3600±1225） ml, t=10.251, P=0.000]. Operation time and postoperative duration of hospitalization of the study group were shorter than those of the control group [（197±45） min vs （284±44） min, t=5.850,P=0.000; （6.7±1.3） d vs （8.2±2.2） d, t=2.272,P=0.029]. There was no statistical difference on hysterectomy rate between the two groups [11/13 vs 89%（25/28）, ）C2-0.181,P=0. 670）]. In addition, two cases of reoperation, one case of pulmonary edema, two cases of coagulation disorder, one case of venous thrombosis in lower limbs, one case of renal dysfunction and pulmonary edema were reported in the control group, but none in the study group. Conclusions Prophylactic bilateral internal lilac arteries balloonocclusion is effective in reducing intraoperative blood loss, transfusion, and relative complications in patients with pernicious placenta previa complicated with placenta accreta. Key words: Placenta previa ; Placenta accreta ; Iliac artery ; Embolization, therapeutic

Vasa Previa

To review experience with diagnosis, clinical associations, and outcomes of vasa previa in a single institution. This was a retrospective review of all identified vasa previa cases from January 1 1990, to June 30, 2010. Sixty cases of vasa previa were identified (53 singletons, seven twins); 56 cases were diagnosed before delivery. An abnormal cord insertion or abnormal placental location was present in 55 cases. Missed diagnoses were attributed to technical and observer factors. Preterm bleeding was encountered in 25 (42%) case group participants. Seven case group participants required an emergent delivery, with significant neonatal morbidity and mortality. Twin pregnancies had a significantly earlier median age at delivery of 32 weeks of gestation compared with 35 weeks of gestations in singletons (P=.01). The seven twin pregnancies had a 28.6% emergent preterm delivery rate, whereas singletons had a 4.1% rate (P=.07). In 14 case group participants, the membranous fetal vessel was located in the lower uterus and not directly over the cervix. The vessel location was not related to the risk of emergent delivery. Transvaginal ultrasound scans of at-risk patients can identify most cases of vasa previa. Preterm bleeding does not usually require immediate delivery. The rate of emergent preterm delivery was low in singleton pregnancies. Twins were delivered, on average, 3 weeks earlier than singletons. III.

A comparative study of neonatal outcomes in placenta previa versus cesarean for other indication at term

Objective: Currently, no ACOG guidelines address the issue of the optimal timing of delivery in placenta previa. Though there is an increased risk of neonatal morbidity and mortality when electively delivered preterm, it is unclear whether adverse neonatal outcomes exist when these pregnancies make it beyond term. By comparing neonatal outcomes amongst pregnancies with placenta previa versus those from cesarean for another indication at term, the objective of this study was to determine whether placenta previa is an independent risk factor for adverse neonatal outcomes at term.Methods: We conducted a population-based cohort-study using the CDC’s Linked Birth–Infant Death data from the United States. The effect of placenta previa on the risk of adverse neonatal outcomes was estimated using unconditional logistic regression analysis, adjusting for relevant confounders.Results: Our cohort consisted of 3 550 842 deliveries meeting inclusion criteria. The incidence of placenta previa at term was 1.3/1000 (n = 4,492), accounting for 40.6% of all previa cases. Relative to cesareans for other indications, pregnancies with placenta previa had an increased risk of IUGR 3.20 [2.50–4.10], SGA 2.70 [2.45–2.97], respiratory distress 3.82 [2.91–5.00], prolonged ventilation 3.41 [2.70–4.32] and neonatal anemia 6.87 [4.43–10.65]. Rates of meconium aspiration syndrome, seizures, birth injury and overall infant mortality do not appear to be affected by this condition.Conclusion: Relative to cesareans for other indications, placenta previa is associated with increased morbidity, but not mortality, at term. This information might be helpful in the development of future guidelines, which are currently needed to guide and standardize clinical practice regarding the optimal timing of delivery in placenta previa.

Prenatal diagnosis and management of vasa previa: A 6‐year review

To evaluate the methods of screening and prenatal diagnosis of vasa previa. We reviewed cases of vasa previa in our hospital between January 2002 and December 2007. During this period, we visualized the site of cord insertion using transabdominal ultrasonography and observed the internal os using gray-scale transvaginal ultrasonography. A diagnosis of vasa previa was confirmed by transvaginal color Doppler imaging. We encountered 10 cases of vasa previa among 5131 deliveries. All cases had one or more known risk factors. In all of the four cases that underwent screening in the second trimester (i.e. between 20 and 25 weeks of gestation), the diagnosis was correct. Routine ultrasonography detected in only three of the other six cases of vasa previa that were referred to our hospital after 26 weeks of gestation. Of the other three cases referred after 26 weeks of gestation, in two cases vasa previa was detected by detailed examination using color Doppler transvaginal ultrasonography after fetal heart rate monitoring detected the presence of non-reassuring fetal status; in the remaining case, we were unable to make an antenatal diagnosis. Non-reassuring fetal status was seen on fetal heart rate monitoring in four of the five detected cases complicated by preterm labor. We consider that the best timing of antenatal screening for vasa previa is the second trimester. Non-reassuring fetal heart rate pattern without other possible causes warrants detailed examination of vasa previa.