Ultrasound diagnosis of placental and umbilical cord anomalies in singleton pregnancies resulting from in-vitro fertilization

INTRODUCTION

placental anomalies can affect fetal and maternal outcome due to severe maternal hemorrhage potentially resulting in hysterectomy and cord accident including abruption that can determine fetal damage or death. The aims of our study are to determine if the rate of placental and umbilical cord anomalies are more common in IVF singleton pregnancies compared to spontaneous pregnancies; to evaluate the role of ultrasound in screening for these anomalies and to investigate if oocyte donor fertilization is an additional risk factor for the development of these anomalies.

METHODS

this was a prospective cohort study involving two tertiary centers. Patients with a singleton pregnancy conceived with IVF and patients presenting with a spontaneous conception were recruited between 1^st May 2019 to 31^st March 2021. A total of 634 pregnancies were enrolled in the study. All patients underwent similar antenatal care, which included ultrasound examinations at 11-14, 19-22 and 33-35 weeks. Ultrasound findings of placental and/or umbilical cord abnormalities were recorded using the same protocol for both groups and confirmed after birth.

RESULTS

IVF pregnancies had a significantly higher risk of low-lying placenta, placenta previa, bilobed placenta and velamentous cord insertion (VCI) compared with spontaneous pregnancies. In the heterologous subgroup there was a significant increased incidence of placenta accreta spectrum (PAS) disorders than in spontaneous pregnancies. All these anomalies were identified prenatally on ultrasound imaging and confirmed at birth.

DISCUSSION

IVF pregnancies in general and those resulting from donor oocyte in particular are at higher risk of placental and umbilical cord abnormalities compared to spontaneous pregnancies. These anomalies can be diagnosed accurately at the mid-trimester detailed fetal anomaly scan and our findings support the need for a targeted ultrasound screening of these anomalies in IVF pregnancies.

Examination of a Stillbirth Workup: A Rural Statewide Experience

OBJECTIVE

The objective of our study was to determine whether recommended assessments were conducted on stillbirths delivered in our predominantly rural state.

METHODS

This was a descriptive study of stillbirths delivered in a rural state and included in one site of the Birth Defects Study to Evaluate Pregnancy Exposures stillbirth study. Hospital and fetal death records were examined to determine whether the following areas were evaluated: genetic testing (noninvasive perinatal testing, quad screen, amniocentesis/chorionic villus sampling with karyotype, microarrays, fetal tissue specimen), placenta/membrane/cord sent for pathologic examination, examination of the stillbirth after delivery by the healthcare provider, and fetal autopsy was performed.

RESULTS

From July 1, 2015 to June 30, 2020, there were 1108 stillbirths delivered in Arkansas. The most frequent assessments undertaken were placental pathology (72%), genetic testing (67%), fetal inspection (31%), and autopsy (13%). All four assessments were done in 2% of stillbirth cases, three assessments in 27%, two assessments in 47%, one assessment in 14%, and no assessment in 15%. There was no association between stillbirth assessment evaluation by gestational age (<28 weeks and > 28 weeks; P = 0.221); however, there was an overall association between hospital delivery volume with number of components completed (P < 0.0001). Hospitals with >2000 deliveries had a higher proportion of three or four completions compared with those hospitals with <1000 deliveries or 1000 to 2000 deliveries (P = 0.021 and P < 0.0001).

CONCLUSIONS

Fetal stillbirth assessment is suboptimal in our rural state, with 15% of stillbirths having no assessment and only 2% having all four assessments. There is no association between stillbirth assessment and gestational age (<28 weeks vs >28 weeks), but there is a correlation between delivery volume and stillbirth assessment.

Advanced maternal age causes premature placental senescence and malformation via dysregulated α-Klotho expression in trophoblasts

Advanced maternal age (AMA) pregnancy is associated with higher risks of adverse perinatal outcomes, which may result from premature senescence of the placenta. α-Klotho is a well-known antiaging protein; however, its expression and effect on the placenta in AMA pregnancies have not yet been fully elucidated. The expression patterns of α-Klotho in mouse and human placentas from AMA pregnancies were determined by Western blotting and immunohistochemistry (IHC) staining. α-Klotho expression in JAR cells was manipulated to investigate its role in trophoblastic senescence, and transwell assays were performed to assess trophoblast invasion. The downstream genes regulated by α-Klotho in JAR cells were first screened by mRNA sequencing in α-Klotho-knockdown and control JAR cells and then validated. α-Klotho-deficient mice were generated by injecting klotho-interfering adenovirus (Ad-Klotho) via the tail vein on GD8.5. Ablation of α-Klotho resulted in not only a senescent phenotype and loss of invasiveness in JAR cells but also a reduction in the transcription of cell adhesion molecule (CAM) genes. Overexpression of α-Klotho significantly improved invasion but did not alter the expression of senescence biomarkers. α-Klotho-deficient mice exhibited placental malformation and, consequently, lower placental and fetal weights. In conclusion, AMA results in reduced α-Klotho expression in placental trophoblasts, therefore leading to premature senescence and loss of invasion (possibly through the downregulation of CAMs), both of which ultimately result in placental malformation and adverse perinatal outcomes.

Prenatal Diagnosis of Vasa Previa by Routine Transvaginal Color Doppler

The prenatal diagnosis of vasa previa is essential to achieving a safe delivery in patients who suffer from the condition. Transvaginal ultrasound with color Doppler performed at the time of a routine mid-trimester ultrasound is a valuable tool in terms of achieving a timely and accurate diagnosis of vasa previa.

Fetal Autopsy-Categories and Causes of Death at a Tertiary Care Center

BACKGROUND

A fetus is defined from 8 weeks after conception until term while in the uterus. Fetal death is defined as death of the fetus before the complete expulsion or extraction from the mother, irrespective of the duration of pregnancy that is not an induced termination of pregnancy. The causes of fetal death determined after fetal autopsy can be categorized according to the classification proposed by Cunningham and Hollier as fetal, placental, and maternal.

METHODS

All fetuses dying in utero, that is, prior to birth, regardless of the gestational age, to the mothers admitted in the Department of Obstetrics and Gynecology along with the respective placentas were received in the Department of Pathology, MGM Medical College, Aurangabad, after an informed and written consent from October 26, 2017, to October 30, 2019, and were included in this study. Clinical details along with obstetric history and antenatal ultrasonographic findings were also recorded. Anthropometric examination of the fetus was performed and evisceration was then done using the Rokitansky technique. Representative sections from each of the organs were taken and kept in tissue cassettes and processed for routine hematoxylin and eosin staining.

RESULTS

This study was done on 33 cases of fetal death. Most fetal deaths occurred in the gestational age between 15 and 19 weeks (14 cases [42.42%]) and the least amount during 35 to 39 weeks (2 cases [6.06%]). The cause of death could not be ascertained in 6 cases (18.18%), whereas the maximum cases had fetal factor as the cause of death (15 cases [45.45%]). Maternal causes were seen in only 4 cases (12.12%). Gestational hypertension was seen to be the most common maternal factor associated with fetal death, which comprised 24.24% of cases (8 of 33). Thirteen of the total 33 cases did not have any associated obstetric complication. Of the total 33 fetal deaths, only 7 had associated placental defects on gross examination. Twenty-six placentas did not show any gross abnormality. Of these 7 cases, 5 were seen to have placental infarction.

CONCLUSIONS

Fetal autopsy is a valuable and cost-effective modality for the confirmation of cause of fetal death. Fetal autopsy can also prove beneficial to the parents in planning for future pregnancies. Fetal autopsy can serve as the ultimate tool in diagnosing cause of fetal death in cases where no other diagnostic clue is available. Therefore, it should be encouraged and couples to be counseled regarding its importance and clinical utility.

Prevalence of placental dichotomy, fetal cardiomegaly and starry-sky liver in twin anemia-polycythemia sequence

OBJECTIVE

To investigate the prevalence of three additional ultrasound markers, placental dichotomy, cardiomegaly and 'starry-sky' liver, in monochorionic twin pregnancy with twin anemia-polycythemia sequence (TAPS).

METHODS

All monochorionic twin pregnancies, diagnosed antenatally with TAPS at our center between 2006 and 2019, were reviewed retrospectively for the presence of placental dichotomy, cardiomegaly in the donor twin and a starry-sky liver in the recipient twin. TAPS was diagnosed based on delta middle cerebral artery (MCA) peak systolic velocity (PSV) > 0.5 multiples of the median. The primary outcome was the prevalence of placental dichotomy, cardiomegaly, starry-sky liver and at least one of these markers in both spontaneous and post-laser TAPS. The secondary outcome was the prevalence of these ultrasound markers according to the antenatal stage of TAPS.

RESULTS

A total of 91 monochorionic twin pregnancies with TAPS were eligible for analysis. Placental dichotomy was observed in 44% (40/91) of TAPS cases. A total of 70% (64/91) of the TAPS donors developed cardiomegaly and a starry-sky liver was identified in 66% (53/80) of the TAPS recipients. The prevalence of cardiomegaly and starry-sky liver was roughly comparable between spontaneous and post-laser TAPS (69% (33/48) vs 72% (31/43) and 64% (25/39) vs 68% (28/41), respectively). Pregnancies with spontaneous TAPS showed a higher prevalence of placental dichotomy compared with post-laser TAPS (63% (30/48) vs 23% (10/43)). At least one of the three ultrasound markers was detected in 86% (78/91) of TAPS cases, meaning that 14% (13/91) of cases presented solely with discordant MCA-PSV values. There was a trend towards increased prevalence of all three ultrasound markers with increasing antenatal TAPS stage.

CONCLUSIONS

Placental dichotomy, fetal cardiomegaly and a starry-sky liver are commonly found in TAPS pregnancy. Investigating the presence of these ultrasound markers can be of additional help in improving antenatal detection of TAPS in monochorionic twin pregnancy. © 2019 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

Second-Trimester Ultrasound-Measured Umbilical Cord Insertion-to-Placental Edge Distance: Determining an Outcome-Based Threshold for Identifying Marginal Cord Insertions

OBJECTIVES

We sought to study potential diagnostic criteria for marginal placental cord insertions as determined by associations with obstetric outcomes.

METHODS

This single-center retrospective cohort investigation included singleton gestations delivering from January 1, 2012, to December 31, 2016, and having a standard or detailed fetal ultrasound examination from 18 weeks to 21 weeks 6 days. Cord insertion-to-placental edge distances were used to create a referent comparison group and 3 patient groups: greater than 3.0 cm (comparison); greater than 2.0 to 3.0 cm (group 1); greater than 1.0 to 2.0 cm (group 2); and 1.0 cm or less (group 3). The primary outcome consisted of any one of spontaneous delivery before 37 weeks, fetal growth restriction, oligohydramnios, placental abruption, or intrauterine fetal demise.

RESULTS

The numbers of participants and mean distances ± SDs for the comparison group and groups 1 to 3, respectively, were 628 and 4.68 ± 1.17 cm, 106 and 2.52 ± 0.26 cm, 131 and 1.60 ± 0.29 cm, and 77 and 0.36 ± 0.37 cm, respectively. The primary outcome was significantly associated only with cord insertion-to-placental edge distances of 1.0 cm or less (adjusted odds ratio, 3.05; 95% confidence interval, 1.73-5.38).

CONCLUSIONS

Marginal cord insertions may be diagnosed when the cord insertion-to-placental edge distance is 1.0 cm or less.

Comparison between abdominal ultrasound and nuclear magnetic resonance imaging detection of placenta accreta in the second and third trimester of pregnancy

This study is to determine accuracy of abdominal ultrasound and nuclear magnetic resonance imaging (MRI) for placenta accreta in the second and third trimester of pregnancy and to define the most relevant features of abdominal ultrasound and MRI for placenta accreta prediction.Between September 2012 and September 2018, 245 high risk of placenta accreta in the second trimester of pregnancy were prenatal diagnosed by abdominal ultrasound and MRI and they were followed up until the end of pregnancy.Forty-six patients at the second trimester of pregnancy and 40 patients at the third trimester of pregnancy were confirmed as placenta accreta. For the second and third trimester of pregnancy, the sensitivity (Se), specificity (Sp), positive and negative predictive value (PPV and NPV) of abdominal ultrasound were 95.65% versus 97.50%, 91.78% versus 90.70%, 88% versus 83%, and 97% versus 99%, respectively, while the Se, Sp, PPV, and NPV of MRI were 89.13% versus 92.50%, 87.67% versus 8721%, 82% versus 77%, and 93% versus 96%, respectively. Five features having significant statistical differences between normal placentation women and placenta accreta patients in second or third trimester of pregnancy, including loss of the normal retroplacental clear space, thinning or disappearance of the myometrium, increased vascularization at the uterine serosa-bladder wall interface, and vascularization perpendicular to the uterine wall on abdominal ultrasound, and uterine bulging and dark intraplacental bands on MRI.Abdominal ultrasound and MRI for placenta accreta in the second and third trimester of pregnancy could provide meaningful imaging evidences.

Role of 2-Dimensional Ultrasound Imaging in Placental and Umbilical Cord Morphometry: Literature and Pictorial Review

Abnormalities of the placenta and umbilical cord have been associated with adverse pregnancy outcomes. Antenatal detection of placental and umbilical cord abnormalities using ultrasound (US) imaging is now gaining popularity with the advancements in obstetric US. This article reviews the use of 2-dimensional obstetric US as a tool to measure and assess placental and umbilical cord morphometry. It highlights the potential role of placental and umbilical cord morphometry as a valuable component of the screening tool for high risk pregnancies and identifies the need for further research to examine its feasibility.

Unexplained Case of Intrauterine Fetal Demise Resolved: Case Report and Literature Review

The association between umbilical cord ulceration and intestinal atresia has been previously established. Umbilical cord ulceration is a seemingly rare, potentially life threatening complication of intestinal atresia. The exact etiological mechanism is unknown and recent literature indicates more intensive prenatal monitoring may alter fetal outcome. In this paper we will review the previously reported cases of intestinal atresia complicated by umbilical cord ulceration and comment on the pathophysiological mechanism of umbilical cord ulceration, with emphasis on the unique location of the atresia at the gastroduodenal junction in our case.

Placenta membranacea: an anormaly of the placenta: Three case reports

RATIONALE

The placenta membranacea (PM) is a rare type of placental abnormality, which is associated with placenta previa, antepartum hemorrhage (APH), postpartum hemorrhage (PPH), chorioamnionitis, fetal growth restriction (FGR), preterm birth even stillbirth. The purpose of this case report is to summarize the characteristics and analyze the relevant factors of PM.

PATIENTS CONCERNS

Repetitive B-ultrasound of the first patient demonstrated a thin placenta covering the most part of uterine wall, which completely covers the internal cervical ostium for 22 weeks. B-ultrasound of the second patient showed placenta partially covering the internal cervical ostium and fetus small for gestation age for 23 days. The third patient complained of abdominal pain and vaginal discharge for 1 day.

DIAGNOSES

Diagnosis of PM is based on Doppler ultrasound apparatus, and confirmed by pathology.

INTERVENTIONS AND OUTCOMES

In the first patient, elective cesarean section was performed. The second patient required termination of pregnancy due to poor postnatal outcome. The third patient underwent intrauterine fetal death. Of these 3 cases, one delivered a term fetus by cesarean section complicated with placenta previa and placenta accreta, one terminated the pregnancy because of serious fetal growth retardation, and the other underwent intrauterine fetal death.

LESSONS

High-resolution color Doppler ultrasound apparatus can improve the diagnostic accuracy, and close antenatal surveillance followed by proper arrangement of delivery may improve neonatal outcomes.

Morbidly adherent placenta: One-year case series in a tertiary hospital

OBJECTIVE

To analyse the clinical characteristics of patients with morbidly adherent placenta (MAP). Findings of this study will be used to identify patients at risk of MAP and to outline the best management strategy to deal with this devastating condition.

METHODS

Delivery records in Hospital Sultanah Nur Zahirah, Terengganu from 1st. January 2016 until 31st. December 2016 were reviewed and analysed.

RESULTS

Out of the 15,837 deliveries, eight cases of MAP were identified. Six out of eight patients had previous caesarean scar with concomitant placenta praevia, the other two patients had previous caesarean scar with history of placenta praevia in previous pregnancies. Seven out of eight cases were suspected to have MAP based on risk factors. Correct diagnosis was made by ultrasound in five patients, all with histologically confirmed moderate/severe degree of abnormal placentation. The other two cases of 'unlikely MAP', demonstrated segmental MAP intra-operatively with histologically confirmed milder degree of abnormal placentation. Total intraoperative blood loss ranged from 0.8 to 20 litres. Prophylactic internal iliac artery balloon occlusion was associated with significantly less blood loss.

CONCLUSION

Antenatal diagnosis is essential in outlining the best management strategy in patients with MAP. Ultrasound may not be accurate in ruling out lower degree of MAP. Apart from having a scarred uterus with concomitant placenta praevia, history of having placenta praevia in previous pregnancy is also a risk factor for MAP. Prophylactic internal iliac artery balloon occlusion is associated with significantly less blood loss and should be considered in cases suspected with MAP.

Factors associated with increased levels of brain natriuretic peptide and cardiac troponin I during the peripartum period

BACKGROUND

We aimed to investigate the values and the changes of brain natriuretic peptide (BNP) and cardiac troponin in pregnant women.

METHODS AND RESULTS

We prospectively collected the data of 405 pregnant women who were treated at Japanese general hospital between 2012 and 2013. We analyzed their laboratory data and echocardiographic findings during the third trimester (28-30 weeks' gestation) and within 4 days of delivery. In addition, we evaluated the factors associated with elevation of BNP and cardiac troponin I (cTnI) levels. The pregnant women were 33.8 ± 5.0 years old and the prevalence of pregnancy induced hypertension (PIH) and placental abnormality was 4.2% and 2.5%, respectively. BNP levels increased after delivery (13.2 pg/mL vs. 23.5 pg/mL; P <0.001), correlated with increased left ventricular diastolic dimension (P = 0.035), left atrial dimension (P <0.001), and decreased hemoglobin (P <0.001). Moreover, cTnI levels increased to over 0.015 ng/mL after delivery in 4.0% of pregnant women. In multivariate analysis, PIH (OR: 18.71, P = 0.003), placental abnormality (OR: 26.78, P = 0.007), and decreased hemoglobin after delivery (OR: 2.59, P <0.001) were the factors associated with elevated cTnI.

CONCLUSIONS

BNP levels increased in association with cardiac chamber enlargement and decreased hemoglobin after delivery. Additionally, the factors affecting elevated cTnI levels were related to labor and delivery.

Twin-to-Twin Transfusion Syndrome: A Case Report

PURPOSE

To present a case of twin-to-twin transfusion syndrome (TTTS), followed by discussion of the etiology, pathophysiology, prenatal diagnosis, management, complications, prognosis, and family considerations.

METHODS

A literature review was conducted using MEDLINE, PubMed, CINAHL, ProQuest, and Google Scholar. The search resulted in 593 articles; 25 relevant articles were chosen.

RESULTS

Approximately 1 of every 250 cases of monochorionic twins acquire TTTS. The progression of TTTS is unpredictable; nontreatment and early onset have been associated with >90 percent mortality of both twins. Neurodevelopmental impairment, preterm birth, renal hypoperfusion, growth restriction, cardiomyopathy, and hydrops fetalis have been associated with TTTS.

LIMITATIONS

A paucity of research and case reports exists, limiting recommendations for optimal diagnosis, management, and treatment regimens.

IMPLICATIONS FOR PRACTICE

TTTS is unpredictable in progression; earlier identification of chorionicity, diagnosis of TTTS, and improvement of treatment and management have the potential to improve the mortality and morbidity outcomes associated with TTTS.

Automatic Lacunae Localization in Placental Ultrasound Images via Layer Aggregation

Accurate localization of structural abnormalities is a precursor for image-based prenatal assessment of adverse conditions. For clinical screening and diagnosis of abnormally invasive placenta (AIP), a life-threatening obstetric condition, qualitative and quantitative analysis of ultrasonic patterns correlated to placental lesions such as placental lacunae (PL) is challenging and time-consuming to perform even for experienced sonographers. There is a need for automated placental lesion localization that does not rely on expensive human annotations such as detailed manual segmentation of anatomical structures. In this paper, we investigate PL localization in 2D placental ultrasound images. First, we demonstrate the effectiveness of generating confidence maps from weak dot annotations in localizing PL as an alternative to expensive manual segmentation. Then we propose a layer aggregation structure based on iterative deep aggregation (IDA) for PL localization. Models with this structure were evaluated with 10-fold cross-validations on an AIP database (containing 3,440 images with 9,618 labelled PL from 23 AIP and 11 non-AIP participants). Experimental results demonstrate that the model with the proposed structure yielded the highest mean average precision (mAP=35.7%), surpassing all other baseline models (32.6%, 32.2%, 29.7%). We argue that features from shallower stages can contribute to PL localization more effectively using the proposed structure. To our knowledge, this is the first successful application of machine learning to placental lesion analysis and has the potential to be adapted for other clinical scenarios in breast, liver, and prostate cancer imaging.

Altered fetal growth, placental abnormalities, and stillbirth

Background

Worldwide, stillbirth is one of the leading causes of death. Altered fetal growth and placental abnormalities are the strongest and most prevalent known risk factors for stillbirth. The aim of this study was to identify patterns of association between placental abnormalities, fetal growth, and stillbirth.

Methods and findings

Population-based case-control study of all stillbirths and a representative sample of live births in 59 hospitals in 5 geographic areas in the U.S. Fetal growth abnormalities were categorized as small (<10th percentile) and large (>90th percentile) for gestational age at death (stillbirth) or delivery (live birth) using a published algorithm. Placental examination by perinatal pathologists was performed using a standardized protocol. Data were weighted to account for the sampling design. Among 319 singleton stillbirths and 1119 singleton live births at ≥24 weeks at death or delivery respectively, 25 placental findings were investigated. Fifteen findings were significantly associated with stillbirth. Ten of the 15 were also associated with fetal growth abnormalities (single umbilical artery; velamentous insertion; terminal villous immaturity; retroplacental hematoma; parenchymal infarction; intraparenchymal thrombus; avascular villi; placental edema; placental weight; ratio birth weight/placental weight) while 5 of the 15 associated with stillbirth were not associated with fetal growth abnormalities (acute chorioamnionitis of placental membranes; acute chorioamionitis of chorionic plate; chorionic plate vascular degenerative changes; perivillous, intervillous fibrin, fibrinoid deposition; fetal vascular thrombi in the chorionic plate). Five patterns were observed: placental findings associated with (1) stillbirth but not fetal growth abnormalities; (2) fetal growth abnormalities in stillbirths only; (3) fetal growth abnormalities in live births only; (4) fetal growth abnormalities in stillbirths and live births in a similar manner; (5) a different pattern of fetal growth abnormalities in stillbirths and live births.

Conclusions

The patterns of association between placental abnormalities, fetal growth, and stillbirth provide insights into the mechanism of impaired placental function and stillbirth. They also suggest implications for clinical care, especially for placental findings amenable to prenatal diagnosis using ultrasound that may be associated with term stillbirths.

Placental Characteristics of Fetuses With Congenital Heart Disease

OBJECTIVES

To investigate whether there is an association between congenital heart disease (CHD) and placental abnormalities.

METHODS

We conducted a case-control study that included cases of infants with CHD who underwent cardiac surgery within 6 months of life at the Johns Hopkins Medical Center from 2000 to 2013, and gestational age-matched normal pregnancy controls (200 neonates per group).

RESULTS

Overall, abnormal placental cord insertion (ie, eccentric, marginal, or velamentous) was associated with CHD (odds ratio, 2.33-3.76). The main cardiac defects associated with abnormal cord insertion were conotruncal defects (relative risk, 3.08; 95% confidence interval [CI], 1.48-6.40; P = .003), left heart disease (relative risk, 2.40; 95% CI, 1.32-4.37; P = .004), and right heart disease (relative risk, 2.22; 95% CI, 1.21-4.07; P = .010). The Placenta-to-birth weight ratio was not associated with CHD. Intrauterine growth restriction was associated with CHD (odds ratio, 3.00; 95% CI, 1.41-6.39; P = .004).

CONCLUSIONS

Abnormal cord insertion, as well as intrauterine growth restriction, was determined to be correlated with the presence of CHD. On the basis of our results, we conclude that cord insertion should be evaluated at routine obstetric sonography, and further fetal heart evaluation is warranted if abnormal cord insertion is detected.

Abnormal ultrasound appearance of the amniotic membranes - diagnostic and significance: a pictorial essay

The obstetrical ultrasound may identify the protrusion of the uterine surface or placental area into the amniotic cavity. The differential diagnosis of this pathology with uterine adhesions, septate uterus, circumvallate placenta, amniotic band or amniotic sheet can be sometimes difficult. The purpose of the pictorial essay is to exemplify the presence of the amniotic sheet and circumvallate placenta in routine obstetrics screening of all trimesters of pregnancy.

Fetoplacental malformations and abnormalities. A retrospective analysis of 398 cases

BACKGROUND

The fetoplacental examination is actually very important and sometimes necessary to confirm or correct prenatal diagnosis.

AIM

to deduce a list of indications of fetoplacental examination and to determine the type and frequency of malformations found.

METHODS

a retrospective study including 398 consecutive fetoplacental examinations, including abortions, stillbirths and children died perinatally. The cases were referred in the department of pathology of the M. Slim Hospital (North Tunis) from 1992 and 2012.

RESULTS

The mean maternal age was 32,58 years. The average gravidity was 2,65 and the average rate was 1,48. Maternal conditions were dominated by preeclampsia. The main indication motivating the request for fetoplacental examination was a spontaneous abortion in 45,73% of cases. The rate of stillbirths was 15,61% and that of children who died in the perinatal period was 13,28%. The sex ratio was 1,4 and the medium term was 19,38 SA. 170 fetuses had abnormalities (43,14%). The most frequent abnormalities were chromosomal aberrations (27,64%), followed by facial abnormalities (25,88%) and central nervous system abnormalities (18,82%). We examined 283 placentas, 49% of them contained abnormalities. Ischemic lesions were the main placental abnormalities (41%).

CONCLUSIONS

  An efficient fetopathological examination should be as complete as possible, including examination of placenta. Everything must be integrated into a data collection and complete clinical information.

Hydrocephalus and arthrogryposis in an immunocompetent mouse model of ZIKA teratogeny: A developmental study

The teratogenic mechanisms triggered by ZIKV are still obscure due to the lack of a suitable animal model. Here we present a mouse model of developmental disruption induced by ZIKV hematogenic infection. The model utilizes immunocompetent animals from wild-type FVB/NJ and C57BL/6J strains, providing a better analogy to the human condition than approaches involving immunodeficient, genetically modified animals, or direct ZIKV injection into the brain. When injected via the jugular vein into the blood of pregnant females harboring conceptuses from early gastrulation to organogenesis stages, akin to the human second and fifth week of pregnancy, ZIKV infects maternal tissues, placentas and embryos/fetuses. Early exposure to ZIKV at developmental day 5 (second week in humans) produced complex manifestations of anterior and posterior dysraphia and hydrocephalus, as well as severe malformations and delayed development in 10.5 days post-coitum (dpc) embryos. Exposure to the virus at 7.5-9.5 dpc induces intra-amniotic hemorrhage, widespread edema, and vascular rarefaction, often prominent in the cephalic region. At these stages, most affected embryos/fetuses displayed gross malformations and/or intrauterine growth restriction (IUGR), rather than isolated microcephaly. Disrupted conceptuses failed to achieve normal developmental landmarks and died in utero. Importantly, this is the only model so far to display dysraphia and hydrocephalus, the harbinger of microcephaly in humans, as well as arthrogryposis, a set of abnormal joint postures observed in the human setting. Late exposure to ZIKV at 12.5 dpc failed to produce noticeable malformations. We have thus characterized a developmental window of opportunity for ZIKV-induced teratogenesis encompassing early gastrulation, neurulation and early organogenesis stages. This should not, however, be interpreted as evidence for any safe developmental windows for ZIKV exposure. Late developmental abnormalities correlated with damage to the placenta, particularly to the labyrinthine layer, suggesting that circulatory changes are integral to the altered phenotypes.

Stillbirth and intrauterine fetal death: role of routine histopathological placental findings to determine cause of death

OBJECTIVES

Placental abnormalities are a common cause of death in stillbirth, ranking second only to unexplained deaths, though there is wide variation in the proportion attributed to placental disease. In clinical practice, interpretation of the significance of placental findings is difficult, since many placental features in stillbirths overlap with those in live births. Our aim was to examine objectively classified placental findings from a series of > 1000 autopsies following intrauterine death in order to evaluate the role of placental histological examination in determining the cause of death.

METHODS

As part of a larger study evaluating several aspects of autopsy findings in intrauterine death, a dedicated database was used to collate antenatal and postmortem examination details for all cases examined between 2005 and 2013 at two tertiary specialist centers in London, UK. Histological findings for placentas were evaluated in relation to the final cause of death.

RESULTS

Among 1064 intrauterine deaths, 946 (89%) cases had the placenta submitted for examination as part of the autopsy. Of these, 307 (32%) cases had the cause of death assigned to abnormalities of the placenta, cord or membranes. Around one third of stillbirths (≥ 24 weeks) had some isolated placental histological abnormality identified, many of uncertain significance, a significantly greater proportion than in cases of second-trimester intrauterine fetal demise (P < 0.0001). The cause of death was ascending infection in 176/946 (19%) cases, peaking at 22 weeks' gestation, with significantly more black mothers having ascending infection compared with other ethnicities (P < 0.0001). Maternal vascular malperfusion was the largest category of placental abnormalities in stillbirth, with peak prevalence in the early third trimester. There were 18 (2%) cases with specific histological abnormalities, including chronic histiocytic intervillositis and massive perivillous fibrin deposition.

CONCLUSIONS

Placental pathologies represent the largest category of cause of intrauterine death. Placental histological examination is the single most useful component of the autopsy process in this clinical setting. A minority of cases are associated with specific placental pathologies, often with high recurrence rates, that can be diagnosed only on microscopic examination of the placenta. Many deaths remain unexplained, although placental histological lesions may be present which are of uncertain significance. A rigorous, systematic approach to placental pathology research and classification may yield better understanding of the significance of placental findings and reduce the rate of unexplained intrauterine deaths. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Placental abnormalities in equine pregnancies generated by SCNT from one donor horse

Placental changes associated with SCNT have been described in several species, but little information is available in this area in the horse. We evaluated the ultrasonographic, gross, and histopathological characteristics of placentas from three successful and five unsuccessful equine SCNT pregnancies, established using cells from a single donor horse. Starting at approximately 6-month gestation, the pregnancies were monitored periodically using transrectal (TR) and transabdominal (TA) ultrasonography (US) to examine the placentas, fetal fluids, and fetuses. Of the five mares that aborted, one mare did so suddenly without any abnormal signs detected by US and four had enlarged umbilical vessels visible on TA-US before abortion. Placental edema (TR-US) and intravascular thrombi in the umbilical cords were seen (TA-US) in two of these four mares; one mare aborted shortly after acute placental separation was identified on TA-US. In three mares that delivered live foals, TA-US showed engorged allantoic vessels and enlarged umbilical vessels. Two of these mares had placental thickening visible on TR-US, interpreted as a sign of placentitis, that subsided after aggressive medical treatment. Seven of the eight placentas were submitted for gross and histopathological examinations after delivery. All placentas had some degree of edema, abnormally engorged allantoic vessels, and enlarged umbilical vessels. Placentitis, large allantoic vesicles, cystic pouches in the fetal part of the cord, and hemorrhages and thrombi in the umbilical vessels were detected only in placentas from mares that aborted. Equine pregnancies resulting from SCNT may be associated with placental pathologies that can be detected using ultrasonography. However, interpreting their severity is difficult. Although placental abnormalities have been observed in SCNT pregnancies in other species, to the best of our knowledge, placentitis has not been previously reported and may be an important complication of equine SCNT pregnancies, leading to pregnancy loss.

Placental histological patterns and uterine artery Doppler velocimetry in pregnancies complicated by early or late pre-eclampsia

OBJECTIVES

To study placental patterns in pregnancies complicated by pre-eclampsia (PE) and to verify whether the findings are related to gestational age (GA) at PE onset and second-trimester uterine artery (UtA) Doppler.

METHODS

For all pre-eclamptic women who delivered between January 2010 and December 2013, we collected retrospectively data related to placental findings and UtA Doppler velocimetry performed at PE onset. The study cohort was divided into groups according to early-onset (EO) or late-onset (LO) PE. Regression analysis was performed to test the ability of UtA Doppler velocimetry to predict subsequent development of placental lesions, after correcting for possible confounders.

RESULTS

Placental abnormalities occurred with a significantly lower incidence in the LO-PE group (n = 72) than in the EO-PE group (n = 105) (P = 0.02). Irrespective of GA at PE onset, UtA pulsatility index (PI) was able to predict macroscopic infarctions (P = 0.001), distal villous hypoplasia (P = 0.03), decidual arteriolopathy (P = 0.03), villous infarcts (P < 0.001), syncytiotrophoblast 'knots' (P = 0.02), microcalcifications (P = 0.02), perivillous fibrin deposition (P = 0.02) and placental hemorrhage (P = 0.01).

CONCLUSIONS

Similar placental abnormalities were present in both EO-PE and LO-PE groups, although with quantitative differences according to GA and UtA Doppler velocimetry at PE onset. Histological patterns were predicted by UtA-PI, independently of GA, supporting the use of UtA Doppler velocimetry as the key criterion in PE classification. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Risk Factors and Adverse Pregnancy Outcomes of Succenturiate Placenta: A Case-Control Study

OBJECTIVE

To identify risk factors associated with succenturiate placenta and to evaluate the association between adverse pregnancy outcomes and succenturiate placenta in singleton pregnancies.

STUDY DESIGN

The total population of women (n = 28,256) with singleton pregnancies who delivered in Zhangqiu City Hospital during the study period between 2002 and 2012 was reviewed. Risk factors. and adverse pregnancy outcomes were evaluated separately among women with and without succenturiate placenta by means of χ² and logistic regression analyses.

RESULTS

The incidence of succenturiate placenta among women with singleton pregnancies was 1.04% (n = 294 of 28,256). Independent risk factors for succenturiate placenta were gestational age, prepregnancy BMI, pelvic infection, prior cesarean section, infertility, and preeclampsia. The succenturiate placenta was associated with a 1.076-, 1.056-, 12.076-, 1.894-, 5.217-, and 4.814-fold increased risk, respectively, as compared to pregnancies with normal cord insertion. For pregnancy outcome comparisons, cases of premature birth, low birth weight, and 5-minute Apgar score ≤ 7 were higher in cases with succenturiate placenta than in those without succenturiate placenta. The rate of cesarean section was increased.

CONCLUSION

The results suggest that the incidence of succenturiate placenta increases along with an increase in pelvic infection, infertility, and preeclampsia. The condition of succenturiate placenta increases the risks for prematurity, impaired fetal growth, and cesarean delivery.

In vitro fertilization represents a risk factor for vasa praevia

Vasa praevia is a rare but very dangerous obstetrical condition. The purpose of our article is to evaluate data available in literature that indicate in vitro fertilization as a risk factor for vasa praevia. PubMed Library and Cochrane Database were searched using the keywords vasa praevia, in vitro fertilization, velamentous cord insertion, placenta praevia. The conditions related to in vitro fertilization that increase the risk of vasa praevia formation were identified and discussed. Also, the diagnosis and management options were reviewed. In vitro fertilization represents a risk factor for vasa praevia and all such pregnancies should be screened by transvaginal ultrasound for vasa praevia.

Vasa previa rupture in velamentous insertion of the umbilical cord: an analysis and report of a case

Ruptured vasa previa in tenn pregnancy is rare but usually catastrophic if emergency delivery is not achieved. The authors present a case of ruptured vasa previa in velamentous cord insertion placenta. The fetus survived after intensive treatment immediately after delivery by cesarean section, but, unfortunately, died after the family gave him up. Defects in the vessel wall architecture were'visualized and confirmed by histopathologic examination and might be responsible for the vessel rupture. Prenatal sonographic identification of cord insertion site into the placenta is encouraged as standard of practice to prevent this accident.

Partial Loss of Genomic Imprinting Reveals Important Roles for Kcnq1 and Peg10 Imprinted Domains in Placental Development

Mutations in imprinted genes or their imprint control regions (ICRs) produce changes in imprinted gene expression and distinct abnormalities in placental structure, indicating the importance of genomic imprinting to placental development. We have recently shown that a very broad spectrum of placental abnormalities associated with altered imprinted gene expression occurs in the absence of the oocyte-derived DNMT1o cytosine methyltransferase, which normally maintains parent-specific imprinted methylation during preimplantation. The absence of DNMT1o partially reduces inherited imprinted methylation while retaining the genetic integrity of imprinted genes and their ICRs. Using this novel system, we undertook a broad and inclusive approach to identifying key ICRs involved in placental development by correlating loss of imprinted DNA methylation with abnormal placental phenotypes in a mid-gestation window (E12.5-E15.5). To these ends we measured DNA CpG methylation at 15 imprinted gametic differentially methylated domains (gDMDs) that overlap known ICRs using EpiTYPER-mass array technology, and linked these epigenetic measurements to histomorphological defects. Methylation of some imprinted gDMDs, most notably Dlk1, was nearly normal in mid-gestation DNMT1o-deficient placentas, consistent with the notion that cells having lost methylation on these DMDs do not contribute significantly to placental development. Most imprinted gDMDs however showed a wide range of methylation loss among DNMT1o-deficient placentas. Two striking associations were observed. First, loss of DNA methylation at the Peg10 imprinted gDMD associated with decreased embryonic viability and decreased labyrinthine volume. Second, loss of methylation at the Kcnq1 imprinted gDMD was strongly associated with trophoblast giant cell (TGC) expansion. We conclude that the Peg10 and Kcnq1 ICRs are key regulators of mid-gestation placental function.

Changes in placental angiogenesis and their correlation with foetal intrauterine restriction

TYPE OF STUDY

Summary review.

SETTING

Department of Gynaecology and Obstetrics, 1st Faculty of Medicine, Charles University and Hospital Na Bulovce, Prague; Department of Physiology, Faculty of Science, Charles University, Prague; Department of Children and Adolescent Medicine, 1st Faculty of Medicine, Charles University in Prague and General Teaching Hospital, Prague.

INTRODUCTION

Intrauterine growth restriction (IUGR) is one of the most common problems in obstetrics. Its incidence is ranging between 3-10%, according to the type of study population and chosen criteria. The cutoff value mainly used for defining the IUGR is weight below the 10th percentile for gestational age. The minority of authors defines the cutoff value under the 5th or 3rd percentile. Any pathological interference with normal vascular development of placenta may have a critical impact on foetal growth and development. Ischaemia is the most common cause of IUGR in normally well-supplied placenta. IUGR is then a consequence of insufficient extension, branching, and dilatation of capillary loops during the formation of terminal villi.

METHODS

This paper is a review focused on up-to-date-known data concerning changes in placental angiogenesis and their impact on IUGR development.

CONCLUSION

The aim of this review is to summarize the knowledge concerning the mechanisms of development of the vascular supply to the placenta under physiological conditions and in conditions that result in IUGR.

Placental mesenchymal dysplasia, a case of intrauterine sudden death

Placental mesenchymal dysplasia (PMD) is a rare condition presenting with enlarged, multicystic placenta like molar changes. Although PMD usually features a normal fetus and the pregnancy often extends into the third trimester, PMD is clinically significant lesion with high rates of FGR, IUFD, and is associated with Beckwith-Wiedemann syndrome (BWS). We report a 30-year old woman at her first pregnancy with intrauterine sudden death at 31 weeks of gestation. The vesicular lesion in her uterus was detected at 10 weeks on ultrasound. The fetus was normal size without any anomaly on ultrasound and normal trophoblastic vascularization by Doppler study during the pregnancy. As the pregnancy advanced, the vesicular lesion decreased in size and no fetal abnormalities were detected. At 28 weeks of gestation an ultrasound detected dilated periumbilical chorionic vessels. We didn't detect severe FGR or abnormal trophoblastic vascularization. At 31 weeks of gestation an intrauterine sudden death of a normal-sized fetus without any anomaly occurred. The placenta was enlarged, and microscopic morphology confirmed a diagnosis of PMD. The chorionic vessels were cirsoid, dilated and tortuous. We determined the rupture of expanded periumbilical chorionic vessels led to fetal death.

Succenturiate lobe of placenta with vessel anomaly: a case report of prenatal diagnosis and literature review

We report the case of a 33-year-old woman with antenatal ultrasound diagnosis of succenturiate placental lobe at 33 weeks confirmed by B-flow rendering, describing the advantages of the application of color Doppler to diagnosis and management of placental anomalies. We searched studies about antenatal diagnosis of succenturiate placental lobe, including only cases in which color Doppler was used. This case underlines the importance of color Doppler in increasing the accuracy of diagnosis and achieving an improved differential diagnosis.

Placental findings in singleton stillbirths

OBJECTIVE

To compare placental lesions for stillbirth cases and live birth controls in a population-based study.

METHODS

Pathologic examinations were performed on placentas from singleton pregnancies using a standard protocol. Data were analyzed overall and within gestational age groups at delivery.

RESULTS

Placentas from 518 stillbirths and 1,200 live births were studied. Single umbilical artery was present in 7.7% of stillbirths and 1.7% of live births, velamentous cord insertion was present in 5% of stillbirths and 1.1% of live births, diffuse terminal villous immaturity was present in 10.3% of stillbirths and 2.3% of live births, inflammation (eg, acute chorioamnionitis of placental membranes) was present in 30.4% of stillbirths and 12% of live births, vascular degenerative changes in chorionic plate were present in 55.7% of stillbirths and 0.5% of live births, retroplacental hematoma was present in 23.8% of stillbirths and 4.2% of live births, intraparenchymal thrombi was present in 19.7% of stillbirths and 13.3% of live births, parenchymal infarction was present in 10.9% of stillbirths and 4.4% of live births, fibrin deposition was present in 9.2% of stillbirths and 1.5% of live births, fetal vascular thrombi was present in 23% of stillbirths and 7% of live births, avascular villi was present in 7.6% of stillbirths and 2.0% of live births, and hydrops was present in 6.4% of stillbirths and 1.0% of live births. Among stillbirths, inflammation and retroplacental hematoma were more common in placentas from early deliveries, whereas thrombotic lesions were more common in later gestation. Inflammatory lesions were especially common in early live births.

CONCLUSIONS

Placental lesions were highly associated with stillbirth compared with live births. All lesions associated with stillbirth were found in live births but often with variations by gestational age at delivery. Knowledge of lesion prevalence within gestational age groups in both stillbirths and live birth controls contributes to an understanding of the association between placental abnormality and stillbirth.

LEVEL OF EVIDENCE

II.

Screen for abnormal mitochondrial phenotypes in mouse embryonic stem cells identifies a model for succinyl-CoA ligase deficiency and mtDNA depletion

Mutations in subunits of succinyl-CoA synthetase/ligase (SCS), a component of the citric acid cycle, are associated with mitochondrial encephalomyopathy, elevation of methylmalonic acid (MMA), and mitochondrial DNA (mtDNA) depletion. A FACS-based retroviral-mediated gene trap mutagenesis screen in mouse embryonic stem (ES) cells for abnormal mitochondrial phenotypes identified a gene trap allele of Sucla2 (Sucla2(SAβgeo)), which was used to generate transgenic mice. Sucla2 encodes the ADP-specific β-subunit isoform of SCS. Sucla2(SAβgeo) homozygotes exhibited recessive lethality, with most mutants dying late in gestation (e18.5). Mutant placenta and embryonic (e17.5) brain, heart and muscle showed varying degrees of mtDNA depletion (20-60%). However, there was no mtDNA depletion in mutant liver, where the gene is not normally expressed. Elevated levels of MMA were observed in embryonic brain. SCS-deficient mouse embryonic fibroblasts (MEFs) demonstrated a 50% reduction in mtDNA content compared with wild-type MEFs. The mtDNA depletion resulted in reduced steady state levels of mtDNA encoded proteins and multiple respiratory chain deficiencies. mtDNA content could be restored by reintroduction of Sucla2. This mouse model of SCS deficiency and mtDNA depletion promises to provide insights into the pathogenesis of mitochondrial diseases with mtDNA depletion and into the biology of mtDNA maintenance. In addition, this report demonstrates the power of a genetic screen that combines gene trap mutagenesis and FACS analysis in mouse ES cells to identify mitochondrial phenotypes and to develop animal models of mitochondrial dysfunction.

Initial experience with a dual-balloon catheter for the management of postpartum hemorrhage

OBJECTIVE

When uterotonics fail to cause sustained uterine contractions and satisfactory control of hemorrhage after delivery, tamponade of the uterus can be effective in decreasing hemorrhage secondary to uterine atony.

STUDY DESIGN

These data are from a postmarketing surveillance study of a novel dual-balloon catheter tamponade device, the Belfort-Dildy Obstetrical Tamponade System (ebb).

RESULTS

A total of 57 women were enrolled: 55 women had the diagnosis of postpartum hemorrhage, and 51 women had uterine balloon placement within the uterine cavity. This study reports the outcomes in the 51 women who had uterine balloon placement within the uterine cavity for treatment of postpartum hemorrhage, as defined by the "Instructions for Use." We further assessed 4 subgroups: uterine atony only (n = 28 women), placentation abnormalities (n = 8 women), both uterine atony and placentation abnormalities (n = 9 women), and neither uterine atony nor placentation abnormalities (n = 6 women). The median (range) time interval between delivery and balloon placement was 2.2 hours (0.3-210 hours) for the entire cohort (n = 51 women) and 1.3 hours (0.5-7.0 hours) for the uterine atony only group (n = 28 women). Bleeding decreased in 22/51 of cases (43%), stopped in 28/51 of cases (55%), thus decreased or stopped in 50/51 of the cases (98%) after balloon placement. Nearly one-half (23/51) of all women required uterine balloon volumes of >500 mL to control bleeding.

CONCLUSION

We conclude that uterine/vaginal balloon tamponade is very useful in the management of postpartum hemorrhage because of uterine atony and abnormal placentation.

Loss of DNMT1o disrupts imprinted X chromosome inactivation and accentuates placental defects in females

The maintenance of key germline derived DNA methylation patterns during preimplantation development depends on stores of DNA cytosine methyltransferase-1o (DNMT1o) provided by the oocyte. Dnmt1o^mat−/− mouse embryos born to Dnmt1^Δ1o/Δ1o female mice lack DNMT1o protein and have disrupted genomic imprinting and associated phenotypic abnormalities. Here, we describe additional female-specific morphological abnormalities and DNA hypomethylation defects outside imprinted loci, restricted to extraembryonic tissue. Compared to male offspring, the placentae of female offspring of Dnmt1^Δ1o/Δ1o mothers displayed a higher incidence of genic and intergenic hypomethylation and more frequent and extreme placental dysmorphology. The majority of the affected loci were concentrated on the X chromosome and associated with aberrant biallelic expression, indicating that imprinted X-inactivation was perturbed. Hypomethylation of a key regulatory region of Xite within the X-inactivation center was present in female blastocysts shortly after the absence of methylation maintenance by DNMT1o at the 8-cell stage. The female preponderance of placental DNA hypomethylation associated with maternal DNMT1o deficiency provides evidence of additional roles beyond the maintenance of genomic imprints for DNA methylation events in the preimplantation embryo, including a role in imprinted X chromosome inactivation.

During oocyte growth and maturation, vital proteins and enzymes are produced to ensure that, when fertilized, a healthy embryo will arise. When this natural process is interrupted, one or more of these essential elements can fail to be produced thus compromising the health of the future embryo. We are using a mouse model, lacking an enzyme (DNMT1o) produced in the oocyte and only required post-fertilization in the early embryo for the maintenance of inherited DNA methylation marks. Here, we reveal that oocytes lacking DNMT1o, when fertilized, generated conceptuses with a wide variety of placental abnormalities. These placental abnormalities were more frequent and severe in females, and showed specific genomic regions constantly deprived of their normal methylation marks. The affected genomic regions were concentrated on the X chromosome. Interestingly, we also found that a region important for the regulation of the X chromosome inactivation process was hypomethylated in female blastocysts and was associated with sex-specific abnormalities in the placenta, relaxation of imprinted X chromosome inactivation, and disruption of DNA methylation later in development. Our findings provide a novel unanticipated role for DNA methylation events taking place within the first few days of life specifically in female preimplantation embryos.

Development of mice without Cip/Kip CDK inhibitors

Timely exit of cells from the cell cycle is essential for proper cell differentiation during embryogenesis. Cyclin-dependent kinase (CDK) inhibitors (CKIs) of the Cip/Kip family (p21, p27, and p57) are negative regulators of cell cycle progression and are thought to be essential for development. However, the extent of functional redundancy among Cip/Kip family members has remained largely unknown. We have now generated mice that lack all three Cip/Kip CKIs (TKO mice) and compared them with those lacking each possible pair of these proteins (DKO mice). We found that the TKO embryos develop normally until midgestation but die around embryonic day (E) 13.5, slightly earlier than p27/p57 DKO embryos. The TKO embryos manifested morphological abnormalities as well as increased rates of cell proliferation and apoptosis in the placenta and lens that were essentially indistinguishable from those of p27/p57 DKO mice. Unexpectedly, the proliferation rate and cell cycle profile of mouse embryonic fibroblasts (MEFs) lacking all three Cip/Kip CKIs did not differ substantially from those of control MEFs. The abundance and kinase activity of CDK2 were markedly increased, whereas CDK4 activity and cyclin D1 abundance were decreased, in both p27/p57 DKO and TKO MEFs during progression from G(0) to S phase compared with those in control MEFs. The extents of the increase in CDK2 activity and the decrease in CDK4 activity and cyclin D1 abundance were greater in TKO MEFs than in p27/p57 DKO MEFs. These results suggest that p27 and p57 play an essential role in mouse development after midgestation, and that p21 plays only an auxiliary role in normal development (although it is thought to be a key player in the response to DNA damage).

Lack of Cul4b, an E3 ubiquitin ligase component, leads to embryonic lethality and abnormal placental development

Cullin-RING ligases (CRLs) complexes participate in the regulation of diverse cellular processes, including cell cycle progression, transcription, signal transduction and development. Serving as the scaffold protein, cullins are crucial for the assembly of ligase complexes, which recognize and target various substrates for proteosomal degradation. Mutations in human CUL4B, one of the eight members in cullin family, are one of the major causes of X-linked mental retardation. We here report the generation and characterization of Cul4b knockout mice, in which exons 3 to 5 were deleted. In contrast to the survival to adulthood of human hemizygous males with CUL4B null mutation, Cul4b null mouse embryos show severe developmental arrest and usually die before embryonic day 9.5 (E9.5). Accumulation of cyclin E, a CRL (CUL4B) substrate, was observed in Cul4b null embryos. Cul4b heterozygotes were recovered at a reduced ratio and exhibited a severe developmental delay. The placentas in Cul4b heterozygotes were disorganized and were impaired in vascularization, which may contribute to the developmental delay. As in human CUL4B heterozygotes, Cul4b null cells were selected against in Cul4b heterozygotes, leading to various degrees of skewed X-inactivation in different tissues. Together, our results showed that CUL4B is indispensable for embryonic development in the mouse.

Causes of death among stillbirths

CONTEXT

Stillbirth affects 1 in 160 pregnancies in the United States, equal to the number of infant deaths each year. Rates are higher than those of other developed countries and have stagnated over the past decade. There is significant racial disparity in the rate of stillbirth that is unexplained.

OBJECTIVE

To ascertain the causes of stillbirth in a population that is diverse by race/ethnicity and geography.

DESIGN, SETTING, AND PARTICIPANTS

A population-based study from March 2006 to September 2008 with surveillance for all stillbirths at 20 weeks or later in 59 tertiary care and community hospitals in 5 catchment areas defined by state and county boundaries to ensure access to at least 90% of all deliveries. Termination of a live fetus was excluded. Standardized evaluations were performed at delivery.

MAIN OUTCOME MEASURES

Medical history, fetal postmortem and placental pathology, karyotype, other laboratory tests, systematic assignment of causes of death.

RESULTS

Of 663 women with stillbirth enrolled, 500 women consented to complete postmortem examinations of 512 neonates. A probable cause of death was found in 312 stillbirths (60.9%; 95% CI, 56.5%-65.2%) and possible or probable cause in 390 (76.2%; 95% CI, 72.2%-79.8%). The most common causes were obstetric conditions (150 [29.3%; 95% CI, 25.4%-33.5%]), placental abnormalities (121 [23.6%; 95% CI, 20.1%-27.6%]), fetal genetic/structural abnormalities (70 [13.7%; 95% CI, 10.9%-17.0%]), infection (66 [12.9%; 95% CI, 10.2%-16.2%]), umbilical cord abnormalities (53 [10.4%; 95% CI, 7.9%-13.4%]), hypertensive disorders (47 [9.2%; 95% CI, 6.9%-12.1%]), and other maternal medical conditions (40 [7.8%; 95% CI, 5.7%-10.6%]). A higher proportion of stillbirths in non-Hispanic black women compared with non-Hispanic white and Hispanic ones was associated with obstetric complications (43.5% [50] vs 23.7% [85]; difference, 19.8%; 95% CI, 9.7%-29.9%; P < .001) and infections (25.2% [29] vs 7.8% [28]; difference, 17.4%; 95% CI, 9.0%-25.8%; P < .001). Stillbirths occurring intrapartum and early in gestation were more common in non-Hispanic black women. Sources most likely to provide positive information regarding cause of death were placental histology (268 [52.3%; 95% CI, 47.9%-56.7%]), perinatal postmortem examination (161 [31.4%; 95% CI, 27.5%-35.7%]), and karyotype (32 of 357 with definitive results [9%; 95% CI, 6.3%-12.5%]).

CONCLUSIONS

A systematic evaluation led to a probable or possible cause in the majority of stillbirths. Obstetric conditions and placental abnormalities were the most common causes of stillbirth, although the distribution differed by race/ethnicity.