Thrombosis of the umbilical vessels revisited. An observational study of 317 consecutive autopsies at a single institution

Umbilical Vascular Thromboembolism: High-Risk Factors, Diagnosis, Management, and Pregnancy Outcomes: A Scoping Review

Umbilical vascular thromboembolism is a rare condition that can lead to serious consequences such as fetal hypoxia, fetal growth restriction, and even stillbirth. However, there is currently a lack of research on the pathology, pathogenesis, clinical management, and prognosis of this condition. Therefore, the purpose of this article is to analyze this condition's high-risk factors, clinical characteristics, pregnancy management, and discuss its corresponding pregnancy outcomes. Databases such as PubMed are searched using the relevant keywords of umbilical vascular thromboembolism in worldwide. And related information is analyzed such as maternal risk factors, fetal risk factors, umbilical cord and placental risk factors, and pregnancy outcomes. The literature search yields 113 articles, 64 of which meet the inclusion criteria for umbilical vascular thromboembolism. There are 4 retrospective cohort studies and 8 case series, the rest are all case reports. A total of 262 cases of umbilical vascular thromboembolism are found. The most common maternal complications and fetal related risk factors are diabetes (25 cases, 9.5%) and stillbirths (106 cases, 40.5%), respectively. Among these 262 cases, 98 (37.4%) cases are found by prenatal ultrasound to have umbilical vascular thromboembolism and the fetus is in a viable state with complete clinical information. In addition, considering the effectiveness and safety of low molecular weight heparin in thromboembolic conditions, twenty-four patients of umbilical artery thromboembolism attempted to use low molecular weight heparin during observation. Maternal diabetes was the highest risk factor for this condition. When umbilical artery thromboembolism occurs, the incidence of stillbirth increases. Premature patients with this condition can continue their pregnancy under close external monitoring. However, due to the small sample size, further research is needed.

Expectant management for umbilical artery thrombosis in the third trimester of pregnancy: a case report

Background

Umbilical artery thrombosis (UAT) is a rare complication of pregnancy and is associated with adverse pregnancy outcomes, including fetal intrauterine distress, intrauterine growth restriction, and still birth. UAT is unpredictable, and prenatal diagnosis is challenging. There is no consensus on the treatment strategy of UAT, especially for patients with prenatal detection of one of the umbilical artery embolisms. In most previous cases, an emergency cesarean section was performed, or intrauterine fetal death occurred at the time of UAT diagnosis.

Case presentation

In this report, we describe a case of thrombosis in one of the umbilical arteries detected by routine ultrasonography at 31+3 weeks of gestation in a 34-year-old woman. Following expectant management with intensive monitoring for 4 four days, an emergency cesarean section was performed because of abnormal fetal umbilical cord blood flow and middle cerebral artery blood flow; the newborn was in good condition at birth. The final umbilical cord histopathology revealed thrombosis in one of the umbilical arteries. Both mother and newborn described in this case underwent long-term follow-up for nearly 2 two years and are currently in good health without any complications.

Conclusions

Based on our experience, obstetricians should comprehensively consider the current gestational age and fetal intrauterine status when UAT is suspected to determine the best delivery time. The appropriate gestational age should be prolonged as long as the mother and fetus are stable when the fetus is immature, trying our best to complete the corticosteroid treatment to promote fetal lung maturity and magnesium sulfate to protect fetal brain. During expectant management, ultrasound monitoring, electronic fetal heart monitoring, and fetal movement counting should be strengthened. Clinicians should ensure that the patients and their families are informed about all potential risks of expectant management for UAT.

Umbilical artery Thrombosis: A case report of prenatal diagnosis and systematic review of the literature

Umbilical Artery Thrombosis (UAT) is an extremely rare complication of pregnancy strongly associated with severe fetal distress and death. The pathogenesis is still unclear but it is often associated with anatomical cord abnormalities that leads to blood stasis and thrombosis formation. Other possible risk factors are maternal thrombophilia, autoimmune disease, gestational diabetes, hypertension disorders of pregnancy and Rh-alloimmunization. The most common clinical symptom is the reduction of fetal movements. The diagnosis is histopathological, but it can be suspected by clinical and prenatal ultrasound findings. Generally, the first choice therapy is the immediate delivery with cesarean section. This study reported a case of a spontaneous intrauterine UAT in a low-risk pregnancy and a systematic review of the literature on clinical, ultrasound and histopathological findings of UAT, in order to help clinicians in the diagnostic process and management of this rare complication.

Hemodynamic changes and perinatal outcome associated with umbilical artery thrombosis: a retrospective study

OBJECTIVE

Poor fetal and perinatal outcomes in fetuses associated with umbilical artery thrombosis (UAT), such as severe intrauterine growth restriction (IUGR) and intrauterine asphyxia have been reported by some case series. Its hemodynamic impact remains unclear. The aim of this study was to evaluate the hemodynamic changes and perinatal outcome in UAT fetuses with a relatively large sample.

METHODS

We included singleton fetuses diagnosed with UAT and with at least one available Doppler evaluation before the end of pregnancy in our center from 2016 to 2023. Fetuses with structural abnormalities and with no follow-up results were excluded. Doppler waveforms from the Umbilical artery (UA), middle cerebral artery (MCA), ductus venosus (DV) and uterine artery (UtA) were routinely evaluated according to ISUOG Practice Guidelines from diagnosis. The same sample of GA-matched normal fetuses with Doppler measurements during the same period were randomly selected as control group.

RESULTS

Eighty-nine singleton fetuses with UAT with at least one Doppler evaluation before the end of pregnancy were identified, 13 fetuses with no follow-up results were excluded. After comprehensive prenatal counseling, 14 cases received urgent cesarean section, the remaining 55 cases received expectant management, the median day between GA at diagnosis and end of pregnancy was 13 (5-53) days (range, 2-159). 7 (7/76, 9.2%) cases occurred stillbirth, and the incidence of IUGR and Neonatal Intensive Care Unit (NICU) admission were 18.4% (14/76) and 13.2% (10/76) respectively. 49 fetuses (49/76, 64.5%) combined with Doppler abnormalities. UA abnormalities (35/76, 46.1%) and MCA abnormalities (34/76, 44.7%) were the most changes at presentation. Compared to control group, UA-EDV was significantly increased in UAT fetuses [21.84 (15.59-26.64) vs. 16.40 (12.43-20.70) cm/s, p < 0.001], UA-PI and UA-RI significantly decreased [0.68 (0.57-0.84) vs. 0.92 (0.79-1.11), p<0.001; 0.51 (0.44-0.59) vs. 0.62 (0.55-0.68), p < 0.001, respectively]. Both the MCA-PSV and MCA-EDV were significantly higher in UAT fetuses [54.60 (48.00-61.34) vs. 44.47 (29.66-57.60) cm/s, p < 0.001; 11.19 (7.84-17.60) vs. 8.22 (5.21-12.00) cm/s, p < 0.001, respectively], this led to a lower MCA-PI and MCA-RI. Meanwhile, DV-PIV was significantly higher in UAT fetuses [0.6 (0.47-0.87) vs. 0.45 (0.37-0.55), p < 0.001], CPR and UtA-PI were no significant difference between these two groups. Multivariate logistic regression analysis showed that DV-PIV was an independent risk factor for adverse pregnancy outcomes (OR 161.922, p<0.001), the area under the ROC curve (AUC) was 0.792 (95% CI 0.668-0.917; p < 0.001).

CONCLUSION

Our data showed serious adverse pregnancy consequences are combined with UAT fetuses. Hemodynamic changes in UAT fetuses showed the remaining artery for compensation and brain perfusion derangement. With a comprehensive and standardized Doppler evaluation, progression of fetal deterioration may be detailed presented.

Double-to-Single Umbilical Artery With a Low Pulsatility Index Leading to Fetal Death: A Case Report and Review of Literature

Single umbilical artery (SUA) may be associated with adverse pregnancy outcomes, such as fetal death, emergency cesarean section, premature delivery, small-for-gestational-age infants, and admission to neonatal intensive care unit, and some SUAs are transformed from originally double umbilical arteries (UA). The pulsatility index (PI) can reflect the resistance of UA, and clinicians attach importance to high PI but easily overlook low levels of it. We reported one case of a pregnant woman who underwent double to single UA accompanied by low UA-PI and finally had intrauterine fetal death. Additionally, the literature regarding SUA and UA-PI is reviewed. This study aims to alert clinicians to the risk of double-to-single UA with low UA-PI and strengthen fetal monitoring and timely intervention. We look forward to more clinical evidence to investigate it.

Case Report of Umbilical Artery Thrombosis in a Patient With a History of Heparin-Induced Thrombocytopenia

Women are at increased risk of thromboembolism during pregnancy because of hypercoagulability associated with pregnancy. Heparin-induced thrombocytopenia (HIT) is an uncommon complication of heparin therapy, and patients with histories of HIT cannot receive any heparin-derived medications. Limited data exist regarding the clinical management of pregnant women with histories of HIT. Umbilical artery thrombosis (UAT) is a rare fetal complication with significant fetal morbidity and mortality. Using the CARE guidelines, we report a case of a woman previously diagnosed with HIT who received long-term anticoagulation therapy and whose fetus developed UAT at 27 weeks gestation. The purpose of this case report is to share our successful expectant management plan of care, which centered on the woman, involved multidisciplinary collaboration, and led to a term cesarean birth.

Foetal death due to extensive extra-abdominal umbilical vein Varix with umbilical vein thrombosis: a case report

BACKGROUND

Foetal anaemia and umbilical vein thrombosis are rare pregnancy complications that can increase the risk of perinatal adverse events, which, in severe cases, can lead to foetal death. During pregnancy, umbilical vein varix (UVV) commonly occurs in the intra-abdominal part of the umbilical vein and is associated with an increased risk of foetal anaemia and umbilical vein thrombosis. However, UVV occurring in the extra-abdominal part of the umbilical vein is rare, especially when accompanied by thrombosis. In this case report, we describe a rare case of an extensive extra-abdominal umbilical vein varix (EAUVV), which ultimately resulted in foetal death due to umbilical vein thrombosis.

CASE PRESENTATION

In this report, we describe a rare case of an extensive EAUVV that was discovered at 25 weeks and 3 days of gestation. During the examination, there were no abnormalities in foetal haemodynamics. The estimated weight of the foetus was only 709 g. In addition to refusing to be hospitalized, the patient refused close monitoring of the foetus. As a result, we were limited to choosing an expectant therapy. The foetus died 2 weeks after diagnosis and was confirmed to have EAUVV with thrombosis after the induction of labour.

CONCLUSION

In the case of EAUVV, lesions are extremely rare, and it is very easy for thrombosis to form, which may result in the death of the child. When determining the next step in the treatment of the condition, the degree of UVV, possible complications, gestational age, foetal haemodynamics, and other relevant factors are strongly connected to the clinical therapy decision, and these factors should be considered comprehensively when making a clinical decision. We recommend close monitoring with hospital admission (to facilities capable of handling extremely preterm foetuses) after variability in delivery for worsening haemodynamic status.

Fetal umbilical artery thrombosis: prenatal diagnosis, treatment and follow-up

BACKGROUND

To analyze the ultrasound imaging and clinical characteristics of fetuses with umbilical artery thrombosis (UAT), explore the potential causes of UAT and construct a prognostic prediction model to guide clinical practice.

METHODS

This was a retrospective cohort study of fetal UAT cases examined at two academic tertiary referral care centers from 2014 to 2020. The basic information of the participants was obtained by interview during follow-up, and data on clinical treatment, delivery conditions, diagnosis and confirmation were obtained through medical records. Probable causes of thrombosis were explored by comparative analysis of the UAT group to the control group and by further regression analysis. Multivariable logistic regression models were used to evaluate risk factors for adverse pregnancy outcomes. Receiver operating characteristic (ROC) curves were constructed to evaluate the diagnostic value of the prognostic prediction model.

RESULTS

Thirty fetuses with UAT were included in this study. UAT occurred mostly in the third trimester of pregnancy, and there was an obvious predominance of right UAT. An abnormal pregnancy history (53.3%) was the most common comorbidity, followed by gestational diabetes mellitus (GDM) (20.0%). GDM and umbilical cord (UC) abnormalities were found to be independent risk factors for the development of UAT. After comprehensive decision-making, over two-thirds of the patients with UAT received urgent treatment, and less than one-third received expectant management. Surprisingly, there were no significant differences in fetal outcomes between the urgent treatment and expectant management groups. Multivariate logistic regression analysis showed that gestational age (GA) at clinical diagnosis and UC abnormalities were independent risk factors for adverse pregnancy outcomes (OR 0.781, p = 0.042; OR 16.779, p = 0.023, respectively). Based on this, we constructed a comprehensive prognostic prediction model. The area under the ROC curve (AUC) was 0.877 (95% CI 0.698-0.970; p < 0.001), which suggested that the combination of GA and UC abnormalities was a better predictor for fetal outcomes in our setting.

CONCLUSION

In summary, maternal GDM and fetal UC abnormalities are independent risk factors for UAT. UAT is more frequently observed on the right side. Moreover, poor clinical outcomes for fetuses with UAT are ascribed mainly to GA and UC abnormalities, which should be comprehensively evaluated to choose the appropriate treatment.

Third trimester intrauterine fetal death: proposal for the assessment of the chronology of umbilical cord and placental thrombosis

The timing of umbilical cord and placental thrombosis in the third trimester intrauterine fetal death (TT-IUFD) may be fundamental for medico-legal purposes, when it undergoes medical litigation due to the absence of risk factors. Authors apply to human TT-IUFD cases a protocol, which includes histochemistry and immunohistochemistry (IHC) for the assessment of thrombi’s chronology. A total of 35 thrombi of umbilical cord and/or placenta were assessed: 2 in umbilical artery, 6 in umbilical vein, 15 in insertion, 10 in chorionic vessels, 1 in fetal renal vein, 1 in fetal brachiocephalic vein. Thrombi’s features were evaluated with hematoxylin–eosin, Picro-Mallory, Von Kossa, Perls, and immunohistochemistry for CD15, CD68, CD31, CD61, and Smooth Muscle Actin. The estimation of the age of the thrombi was established by applying neutrophils/macrophages ratio taking into consideration, according to literature, the presence of hemosiderophagi, calcium deposition, and angiogenesis. To estimate an approximate age of fresh thrombi (< 1 day), a non-linear regression model was tested. Results were compared to maternal risk factors, fetal time of death estimated at autopsy, mechanism, and cause of death. Our study confirms that the maternal risk factors for fetal intrauterine death and the pathologies of the cord, followed by those of the placental parenchyma, are the conditions that are most frequently associated with the presence of thrombi. Results obtained with histological stainings document that the neutrophile/macrophage ratio is a useful tool for determining placental thrombi’s age. Age estimation of thrombi on the first day is very challenging; therefore, the study presented suggests the N/M ratio as a parameter to be used, together with others, i.e., hemosiderophagi, calcium deposition, and angiogenesis, for thrombi’s age determination, and hypothesizes that its usefulness regards particularly the first days when all other parameters are negative.

Umbilical artery thrombosis diagnosed at different gestational ages and fetal outcomes: a case series

BACKGROUND

Umbilical artery thrombosis is a rare complication of pregnancy strongly associated with poor fetal and perinatal outcomes, such as intrauterine asphyxia, fetal growth restriction, and stillbirth. Its pathogenesis remains unclear, and there is the added challenge of selecting an appropriate delivery time to achieve excellent neonatal outcomes.

METHODS

Our Hospital is a critical maternal rescue center with approximately 7000 births annually. We present a series of 8 cases of umbilical artery thrombosis diagnosed at the hospital between Apr 1, 2018, and Jan 31, 2020. We identified the cases through a keyword search of the maternity and pathology information management systems.

RESULTS

Three patients were diagnosed with a transabdominal ultrasound scan and hypoxia on fetal heart monitoring. All three patients had emergency cesarean section delivery. Four patients were observed closely for 5 to 13 weeks from initial detection by an ultrasound scan to delivery. Only one patient was diagnosed after vaginal delivery by Hematoxylin-eosin staining of umbilical cord sections. Seven patients had deliveries by cesarean section, and one patient had a vaginal delivery. All infants were born alive.

CONCLUSIONS

Umbilical artery thrombosis is a challenging and rare condition that can occur at different gestational ages, especially when diagnosed in the third trimester and accompanied by fetal growth restriction. Consequently, these patients require close monitoring of umbilical blood flow and fetal growth and intervention at the appropriate time to achieve an optimal outcome.

A closer look at discordant placental echogenicity: two cases under the microscope

Discordant placental echogenicity is observed in MC pregnancies complicated with twin anemia-polycythemia sequence, but could also belong to complicated singleton gestation.

Thrombosis of Both Umbilical Arteries of a Female Fetus in a Twin Gestation Causing Fetal Demise

Thrombosis of both umbilical arteries is a rare condition, less common than venous thrombosis. They cause a lot of complications during and after delivery. Umbilical artery thrombosis is associated with both maternal predisposing factors and cord abnormalities and is commonly seen in male fetuses. Presenting symptoms are those of intrauterine growth retardation. Ultrasound abdomen and Doppler flow studies are useful in diagnosing this condition. The prognosis is very poor. Histopathological examination is helpful for confirmation. We present a case of both umbilical arteries thrombosis of a female fetus in a twin gestation causing fetal demise.

10 cases of umbilical cord thrombosis in the third trimester

BACKGROUND

Thrombosis of umbilical vessels is a rare occurrence that is difficult to detect during routine antenatal examinations but can lead to poor perinatal outcomes.

OBJECTIVE

The aim of this study is to examine the association between meaningful clinical manifestations and features associated with thrombosis of umbilical vessels, and to evaluate optimal management options.

METHODS

A retrospective study of umbilical cord thrombi cases enrolled between 2015-2019 was carried out. Data were analyzed from the medical archives where the diagnosis of all cases was established by histopathology.

RESULTS

Gross examination reported additional cord abnormalities (7/10), including the irregular length of the umbilical cord, narrowed cord with hyper-coiling, swollen cord with deficiency of Wharton's jelly, placenta velamentous and umbilical infarction. Pathological examination accounted for 10 cases of umbilical cord thrombosis including umbilical artery embolism (3/10), umbilical vein thrombi (5/10) and funisitis (2/10). Clinical findings depicted that the chief complaint was decreased fetal movement companied by nonreactive NST tests (5/10). With the exception of two stillbirths, the remaining pregnancies (8/10) were terminated by cesarean section. All neonates are alive, including one VLBW and three LBW cases.

CONCLUSION

We have observed that umbilical structural dysplasia, maternal coagulation disorder, vascular endothelial injury and elevated blood glucose may lead to the formation of thrombosis. Focus on specific signs during a prenatal ultrasound, EFM monitoring and counting fetal movements can help in early identification of umbilical cord thrombi. Our results support the more effective approach of emergency cesarean section during the third trimester.

Umbilical Cord Abnormalities and Stillbirth

OBJECTIVE

Umbilical cord abnormalities are commonly cited as a cause of stillbirth, but details regarding these stillbirths are rare. Our objective was to characterize stillbirths associated with umbilical cord abnormalities using rigorous criteria and to examine associated risk factors.

METHODS

The Stillbirth Collaborative Research Network conducted a case-control study of stillbirth and live births from 2006 to 2008. We analyzed stillbirths that underwent complete fetal and placental evaluations and cause of death analysis using the INCODE (Initial Causes of Fetal Death) classification system. Umbilical cord abnormality was defined as cord entrapment (defined as nuchal, body, shoulder cord accompanied by evidence of cord occlusion on pathologic examination); knots, torsions, or strictures with thrombi, or other obstruction by pathologic examination; cord prolapse; vasa previa; and compromised fetal microcirculation, which is defined as a histopathologic finding that represents objective evidence of vascular obstruction and can be used to indirectly confirm umbilical cord abnormalities when suspected as a cause for stillbirth. We compared demographic and clinical factors between women with stillbirths associated with umbilical cord abnormalities and those associated with other causes, as well as with live births. Secondarily, we analyzed the subset of pregnancies with a low umbilical cord index.

RESULTS

Of 496 stillbirths with complete cause of death analysis by INCODE, 94 (19%, 95% CI 16-23%) were associated with umbilical cord abnormality. Forty-five (48%) had compromised fetal microcirculation, 27 (29%) had cord entrapment, 26 (27%) knots, torsions, or stricture, and five (5%) had cord prolapse. No cases of vasa previa occurred. With few exceptions, maternal characteristics were similar between umbilical cord abnormality stillbirths and non-umbilical cord abnormality stillbirths and between umbilical cord abnormality stillbirths and live births, including among a subanalysis of those with hypo-coiled umbilical cords.

CONCLUSION

Umbilical cord abnormalities are an important risk factor for stillbirth, accounting for 19% of cases, even when using rigorous criteria. Few specific maternal and clinical characteristics were associated with risk.

A case of prenatal diagnosis of single umbilical artery due to thrombosis diagnosed by the ultrasound finding of “wink-sign”

Objectives

Umbilical artery thrombosis is a significant umbilical cord condition that is associated with adverse pregnancy outcomes. However, no consensus has been reached regarding how umbilical artery thrombosis should be diagnosed or managed because of its rarity and the difficulty associated with an antenatal diagnosis.

Case presentation

Here, we describe a case involving decreased fetal movement and non-reassuring fetal status (NRFS) in which acute umbilical artery thrombosis was prenatally diagnosed. Transabdominal ultrasound showed that the cross-section of the umbilical cord had one normal artery and a small deformed echogenic area. A characteristic ultrasound finding known as the “wink sign” contributed to the prenatal diagnosis.

Conclusions

Evaluation of the umbilical cord enabled the estimation and facilitated the subsequent antenatal management.

Umbilical artery thrombosis: Two case reports

RATIONALE

The umbilical cord is the way to exchange gas, supply nutrients, excrete metabolized. Thrombosis of the umbilical cord leads to fetal hypoxia, which jeopardizes fetal health and can cause fetal death. Umbilical vessel thrombosis, which is rarely reported, is difficult to detect prenatally.

PATIENT CONCERNS

Both pregnant women had an unremarkable pregnancy course until a routine ultrasound scan in the third trimester showed a single umbilical artery. However, one umbilical vein and 2 umbilical arteries were seen during an ultrasound examination at 32 weeks. Case 2 had a better pregnancy outcome because of the timely discovery of this complication.

DIAGNOSIS

Both cases were diagnosed as umbilical artery thrombosis.

INTERVENTIONS

The first patient received no interventions until they reported decreased fetal movements and gradually disappear. The second patient underwent an emergency cesarean section.

OUTCOMES

In Case 1, an emergency ultrasound examination showed intrauterine fetal death, and the patient vaginally delivered a stillborn child weighing 3300 g in a day. In Case 2, a female neonate weighing 2860 g was delivered by cesarean section, and exhibited Apgar scores of 10 and 10 at 1 and 5 minutes.

CONCLUSION

In the late-term abortions, obstetricians should be vigilant if ultrasound imaging shows suspected umbilical vascular thrombosis or shows 1 umbilical artery when there had previously been 2. The fetus should be closely monitored and interventions implemented as early as possible to improve the prenatal detection rate of umbilical vessel thrombosis and avoid adverse pregnancy outcomes.

Comparison of bilateral and unilateral umbilical artery diastolic blood flow abnormalities in monochorionic diamniotic twin pregnancies

Aim: Our study aimed to clarify the prognosis of bilateral and unilateral umbilical artery end-diastolic blood flow abnormalities (BFAs) in monochorionic diamniotic twin pregnancies.Methods: Monochorionic diamniotic twin pregnancies were classified into bilateral (group 1), unilateral (group 2), and no (group 3) umbilical artery end-diastolic BFAs. After the usual obstetric management, short- and long-term prognoses were analyzed.Results: A total of 171 monochorionic diamniotic twins were analyzed and classified into group 1 (13 twins, 7.6%), 2 (12 twins, 7.0%), and 3 (146 twins, 85.4%). Gestational age at delivery was significantly lower in group 1 than in groups 2 and 3 (median, 29.3, 35.6, and 35.6 weeks, respectively; p < .01 and p < .001). The survival rate of fetuses with BFAs was significantly lower in group 1 than in group 2 (23.0% [3/13] versus 100% [12/12]; p < .001). However, the survival rate of the co-twin was not significantly different between groups 1 and 2 (84.6% [11/13] versus 100% [12/12]; p = .48). The survival rate of both fetuses was significantly lower in group 1 than in groups 2 and 3 (53.8% [14/26], 100% [24/24], and 98.6% [288/292], respectively; both p < .001). In cases with fetal therapy, the survival rate of both fetuses tended to be lower in group 1 than in group 2 (44.4% [8/18] versus 83.3% [10/12]; p = .05). In cases without fetal therapy, the gestational age at delivery tended to lower in group 1 than in group 2 and was significantly lower than in group 3 (median, 29.1, 35.6, 35.6 weeks, respectively; p = .05 and p < .05). The survival rate of fetuses with BFA tended to be lower in group 1 than in group 2 (50.0% [2/4] versus 100% [12/12]; p = .05). The survival rate of the co-twin was not significantly different between groups 1 and 2 (100% [4/4] versus 100% [12/12]; p = 1). The survival rate of both fetuses tended to be lower in group 1 than in group 2 and was significantly lower than in group 3 (75% [6/8], 100% [24/24], and 99.2% [278/280], respectively; p = .05 and p < .01).Conclusions: In monochorionic diamniotic twin pregnancies, bilateral umbilical artery end-diastolic BFAs demonstrated a poor prognosis. However, unilateral abnormalities exhibited a good prognosis similar to that in twins with normal umbilical artery blood flow. If such abnormalities are detected during a routine checkup, the umbilical artery pulse wave on the other side should be examined.

Antenatal Microbial Colonization of Mammalian Gut

The widely accepted dogma of intrauterine sterility and initial colonization of the newborn during birth has been blurred by recent observations of microbial presence in meconium, placenta, and amniotic fluid. Given the importance of a maternal-derived in utero infant seeding, it is crucial to exclude potential environmental or procedural contaminations and to assess fetal colonization before parturition. To this end, we analyzed sterilely collected intestinal tissues, placenta, and amniotic fluid from rodent fetuses and tissues from autoptic human fetuses. Total bacterial DNA was extracted from collected samples and analyzed by Next Generation Sequencing (NGS) techniques using hypervariable 16S ribosomal RNA (rRNA) regions (V3-V4). Colonizing microbes were visualized in situ, using labeled probes targeting 16S ribosomal DNA by fluorescent in situ hybridization. The NGS analysis showed the presence of pioneer microbes in both rat and human intestines as well as in rodent placentas and amniotic fluids. Microbial communities showed fetus- and dam-dependent clustering, confirming the high interindividual variability of commensal microbiota even in the antenatal period. Fluorescent in situ hybridization analysis confirmed the microbes' presence in the lumen of the developing gut. These findings suggest a possible antenatal colonization of the developing mammalian gut.

Anatomical Pathology of the Umbilical Cord and Its Maternal and Fetal Clinical Associations in 434 Newborns

Introduction Umbilical cord (UC) abnormalities and their clinical relations in 434 newborns were analyzed. We had previously reported on clinical associations of long and short UCs with any kind of malformation. This study focuses on other UC features (insertion, vessels, entanglements, coiling, and knots) and their associations with clinical characteristics and neonatal prognosis. Methods An observational analytic study was performed on placentas from consecutive deliveries. Ordered logistic regression with bivariate and multivariate analysis was performed to evaluate the relationship between variables of interest concerning UC abnormalities. Results A total of 434 placentas made up the study. UC abnormalities were abnormal insertion, 82 (18.86%); coiling (hypo and hypercoiled), 177 (40.78%); single umbilical artery (SUA), 4 (0.92%); entanglements, 8 (1.84%); true knots, 3 (0.69%); webs in UC base, 9 (2.07%); and right twist, 68 (15.67%). After analyzing maternal and fetal complications during pregnancy, multivariate analysis confirmed the recognized association between malformations and SUA and male gender; further confirmation was also made between hypertensive disorders of pregnancy and true knots. Discussion UC abnormalities associated with undesirable outcomes are varied and should be recognized and described. Clinical factors associated with anatomical UC abnormalities are not completely understood and justify forthcoming studies.

A Case of Umbilical Artery Thrombosis in the Third Trimester of Pregnancy

BACKGROUND Umbilical artery thrombosis is an extremely rare complication during pregnancy. Umbilical artery thrombosis has a poor prognosis and is associated with increased rates of perinatal morbidity, including intrauterine growth restriction (IUGR), and fetal mortality. CASE REPORT We report a rare case of umbilical artery thrombosis, diagnosed by ultrasound, at 33 weeks gestation in a 30-year-old woman who had previously had an uneventful pregnancy. CONCLUSIONS Umbilical artery thrombosis is a rare complication of pregnancy that is associated with high fetal mortality. Management may include planned elective delivery by cesarean section, following antenatal corticosteroid therapy for fetal lung maturation.

Stillbirths at Term: Case Control Study of Risk Factors, Growth Status and Placental Histology

Objective

To investigate the proportion of stillbirths at term associated with abnormal growth using customized birth weight percentiles and to compare histological placental findings both in underweight stillborn fetuses and in live births.

Methods

A retrospective case-control study of 150 singleton term stillbirths. The livebirth control groups included 586 cases of low-risk pregnancies and 153 late fetal growth restriction fetuses. Stillbirths and livebirths from low-risk pregnancies were classified using customized standards for fetal weight at birth, as adequate for gestational age (AGA; 10-90^th percentile), small (SGA; <10^th percentile) or large for gestational age (LGA; >90^th percentile). Placental characteristics in stillbirth were compared with those from livebirths using four categories: inflammation, disruptive, obstructive and adaptive lesions.

Results

There was a higher rate of SGA (26% vs 6%, p<0.001) and LGA fetuses (10.6% vs 5.6%, p<0.05) in the stillbirth group. Among stillbirth fetuses, almost half of the SGA were very low birthweight (≤3°percentile) (12% vs 0.3%, p<0.001). The disruptive (7.3% vs 0.17%;p<0.001), obstructive (54.6% vs 7.5%;p<0.001) and adaptive (46.6% vs 35.8%;p<0.001) findings were significantly more common in than in livebirth-low risk. Placental characteristics of AGA and SGA stillbirth were compared with those of AGA and FGR livebirth. In stillbirths-SGA we found a higher number of disruptive (12.8% vs 0%; p<0.001), obstructive (58.9% vs 23.5%;p<0.001) and adaptive lesions (56.4% vs 49%; p 0.47) than in livebirth-FGR.

Conclusion

The assessment of fetal weight with customized curves can identify fetuses which have not reached their genetically determined growth potential and are therefore at risk for adverse outcomes. Placental evaluation in stillbirths can reveal chronic histological signs that might be useful to clinical assessment, especially in underweight fetuses.

Intrauterine thrombosis of umbilical artery - case report

CONTEXT

Umbilical cord thrombosis is related to greater fetal and perinatal morbidity and mortality. It is usually associated with umbilical cord abnormalities that lead to mechanical compression with consequent vascular ectasia. Its correct diagnosis and clinical management remains a challenge that has not yet been resolved.

CASE REPORT

This study reports a case of umbilical artery thrombosis that occurred in the second half of a pregnancy. The umbilical cord was long, thin and overly twisted and the fetus presented severe intrauterine growth restriction. The clinical and histopathological findings from this case are described.

CONCLUSIONS

This case report emphasizes the difficulty in diagnosing and clinically managing abnormalities of intrauterine life with a high chance of perinatal complications.

Inflammation modulates LC3 expression in human preterm delivery

OBJECTIVE

Autophagy is an inducible intracellular process acting under stressor conditions, such as infections, inflammation and hypoxia. The aim of the present study was to analyze autophagy expression in preterm delivered human placenta.

METHODS

Autophagy marker LC3 was analyzed in 25 consecutive human placentas delivered before 34 weeks of gestation, analyzed by immunohistochemistry, immunofluorescence and quantitative real-time PCR, according to the histologic classification of preterm delivery (PTD) (cases with or without placental inflammatory lesions).

RESULTS

LC3 expression was observed both in cases with and without inflammatory lesions. In cases with histological inflammation, strong immunoreactivity for LC3 autophagic marker was observed in the inflammatory cell infiltration composed by neutrophils. In all PTD cases, trophoblastic cells in chorion laeve express LC3, with variable staining intensity: a significant reduction of LC3 expression was observed in chorion laeve of PTD with histological inflammation compared to PTD without inflammatory lesions. Moreover, the decrement of LC3 staining was observed to be associated to the increasing severity of the histological signs of fetal inflammatory response.

CONCLUSIONS

Our data show that the expression of LC3 varies depending on different histological features, indicating an interesting and possibly clinically relevant relation between autophagy expression levels and the inflammatory status.

Fetal Thrombotic Vasculopathy: Perinatal Stroke, Growth Restriction, and Other Sequelae

Clots in the fetal circulation of the placenta may occlude or narrow the lumens of fetal vessels sufficiently to diminish the placental oxygen and nutritional exchange, causing significant reduction in placental function. When extensive, growth restriction, neonatal encephalopathy, and stillbirth may occur. Propagation of clots in other organs, such as brain, kidney, and liver, may affect the function of these organs, resulting in infarcts and neonatal stroke. This article presents an account of the placental pathology and clinical sequelae of this condition, called fetal thrombotic vasculopathy.

Cell death and cell proliferation in human spina bifida

BACKGROUND

Spina bifida is a multifactorial congenital malformation of the central nervous system. The aim of this study was to ascertain the relevance of cell death/proliferation balance in human spina bifida and to assess autophagy distribution and levels during embryo-fetal development in neural tissue.

METHODS

Five human cases with myelomeningocoele were compared with 10 healthy human controls and LC3 protein expression was also analyzed in mouse embryos. Cell death was evaluated using TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuridinetriphosphate nick end-labeling) assay; cell proliferation was studied by counting Ki67-positive cells, and autophagy was assessed by observing the presence of LC3 punctuate dots.

RESULTS

Comparing human cases and controls (13 to 21 weeks of gestation), we observed a significant increase in TUNEL-positive cells in human spina bifida associated with a significantly decreased proliferation rate, indicating an alteration of the physiological cell rate homeostasis. LC3 distribution was found to be spatiotemporally regulated in both human and murine embryo-fetuses: in early pregnancy a diffuse and ubiquitous LC3 signal was detected. After neural tube closure, an intense LC3-positive signal, normally associated to extra energy requirement, was confined to the Lissauer's tract, the dorsolateral spinal zone containing centrally projecting axons from dorsal root ganglia, at any medullar levels. LC3 signal disappeared from 12 weeks of gestation.

CONCLUSION

In conclusion, this study confirms the fundamental role of cell death/proliferation balance during central nervous system development and reports the changing expression of LC3 protein in mouse and human neural tube. Birth Defects Research (Part A) 106:104-113, 2016. © 2015 Wiley Periodicals, Inc.

Placental histology in clinically unexpected severe fetal acidemia at term

BACKGROUND

Fetal acidemia at birth is defined as a newborn condition wherein the cord blood pH value is less than 7.0. It could represent an association with newborn brain damage; therefore, it is important to investigate which conditions precipitate its occurrence. No extensive placental analysis has been performed in cases of acidotic newborns delivered from low-risk pregnancies.

AIMS

To study placental characteristics in cases with severe fetal acidemia.

STUDY DESIGN

Retrospective case-control study.

SUBJECT

34 cases, 102 controls.

OUTCOME MEASURES

Umbilical artery pH was measured at delivery from a doubly clamped portion of the cord. Placental characteristics were compared between cases with severe fetal acidemia (cord pH at birth <7.0) and controls (normal pH at birth) in term low-risk pregnancies.

RESULTS

Macroscopic placental and umbilical cord characteristics were comparable in cases and controls whereas histological characteristics exhibited differences: diffuse villous edema, increased number of syncytial knots and villous branching abnormalities significantly affected cases more frequently than controls. Diffuse villous edema is related to fetal vascularization and associated with an increase of venous pressure; in our low-risk population, it is conceivable that these changes of fetal flow and pressure occurred in labor during the alteration of fetal heart rate. An increased number of syncytial knots and villous branching abnormalities have been previously associated with chronic placental hypoxic condition; in our low-risk population they could reflect a clinically undetectable hypoxic situation that acted during pregnancy reducing fetal resources to bear labor and delivery.

CONCLUSIONS

Placental histology provides useful information related to fetal acidemia in low-risk term pregnancy.

Four cases of fetal intra-abdominal umbilical vein varix: a single centre's approach to management

Fetal intra-abdominal umbilical vein (FIUV) varix is a rare prenatal abnormality characterised by a focal intrahepatic or extrahepatic dilatation of the intra-abdominal portion of the umbilical vein. Usually, it is an isolated finding, but in some cases it can be associated to other fetal anomalies. Thrombosis is a possible complication of FIUV varix and it can lead to poor fetal or neonatal outcome. We describe four consecutive cases of FIUV varix diagnosed in our Unit and managed with low-dose aspirin (LDA) prophylaxis until the 35th week of gestation. None of the fetuses developed thrombosis of the varix and the neonatal outcomes were good in all the cases.

Pseudotumerous enlargement of the umbilical cord owing to an intra-amniotic varicosity associated with thrombocytopenia

Herein, we describe a male infant with an antenatally diagnosed single umbilical artery and extensive varicosities of the umbilical vein with tumor-like appearances. Consumption coagulopathy occurred postnatally, and surgical resection of the umbilical cord led to a normalization of the platelet count.

Single umbilical artery in twin pregnancies

OBJECTIVE

Our purpose was to evaluate the antenatal incidence of single umbilical artery (SUA) in twin pregnancies according to chorionicity and to assess its relationship with outcome.

METHODS

Consecutive twin pregnancies undergoing ultrasound evaluation at our institutions were included. A targeted sonographic evaluation of the umbilical cord and vessels was performed in all cases. Chorionicity was determined according to standard ultrasound criteria.

RESULTS

A total of 174 twin pregnancies, 100 dichorionic (DC) and 74 monochorionic (MC), were included in the study. An SUA was identified in 17 (9.8%) pregnancies, and in 18 (5.2%) fetuses. No difference was found in the incidence of SUA in DC and MC twins. Among affected pregnancies, all but one DC twin pregnancy were discordant for SUA. Structural and/or chromosomal abnormalities were present in 27.8% of fetuses with SUA. The prevalence of small-for-gestational-age fetuses and of discordant birth weight (> 20% discordance) was higher in the SUA group than in the rest of the population, although these differences were not statistically significant. Twin pairs discordant for SUA had significantly higher weight discordance than those with normal umbilical cords. The sonographic cross-sectional area of the SUA did not appear to show the typical adaptive dilatation usually seen in singleton pregnancies with SUA.

CONCLUSIONS

The incidence of SUA in twins is higher than in singletons, with no difference between MC and DC twins. Intrapair discordance for SUA in identical twins provides evidence against an exclusively genetic origin of this anomaly. The apparent failure of compensatory dilatation of the umbilical artery in twins with SUA may explain in part the higher risk for fetal growth restriction in these cases.