Umbilical cord stricture and overcoiling are common causes of fetal demise

Case report: One case of umbilical vein thrombosis in the second trimester with associated portal vein thrombosis after childbirth

Background

Umbilical vein thrombosis is a rare pregnancy complication, that is difficult to detect prenatally but can lead to poor fetal outcomes.

Case presentation

We described a 33-year-old primiparae who was identified as having umbilical vein thrombosis by ultrasound at 21 weeks gestation, and the neonate was found to have a portal vein thrombus after delivery. Following enoxaparin anticoagulant therapy, the thrombus disappeared within 4 weeks. No thrombus formation occured during the 10-month follow-up, and the baby was in excellent clinical condition.

Conclusion

Owing to the poor fetal outcomes related to umbilical thrombosis, pay attention to abnormal clinical signs during prenatal ultrasound, fetal heart monitoring and counting fetal movements can help in the early identification of umbilical cord thrombosis.The findings highlight the importance of regular prenatal ultrasound evaluation, enabling early detection and monitoring of any anomalies or vascular abnormalities related to the fetal umbilical vein. Further research is warranted to explore the clinical implications and long-term outcomes associated with these findings.

Umbilical Cord Diseases Affecting Obstetric and Perinatal Outcomes

BACKGROUND

(1) The aim of this article is to describe the physiopathology underlying umbilical cord diseases and their relationship with obstetric and perinatal outcomes. (2) Methods: Multicenter case series of umbilical cord diseases with illustrations from contributing institutions are presented. (3) Results: Clinical presentations of prenatal ultrasound findings, clinical prenatal features and postnatal outcomes are described. (4) Conclusions: Analysis of our series presents and discusses how umbilical cord diseases are associated with a wide variety of obstetric complications leading to a higher risk of poor perinatal outcomes in pregnancies. Knowing the physiopathology, prenatal clinical presentations and outcomes related to umbilical diseases allow for better prenatal counseling and management to potentially avoid severe obstetric and perinatal complications.

Comparison of the Autopsy and Placental Findings in Second vs Third Trimester Stillbirth

BACKGROUND

The pathology of second trimester fetal loss is not well-characterized due to lack of comprehensive autopsy studies. The purpose of this study is to compare autopsy pathology of second trimester and third trimester stillbirth.

METHODS

In this retrospective cohort study, fetal autopsies performed in-house with complete placental examination were included. From autopsy reports, maternal demographics, gestational age, sex, body and placental weight, congenital anomalies, and cause of death (COD) were obtained. Immediate COD was coded "probable" or "possible" according to Initial Causes of Fetal Death (INCODE).

RESULTS

Among 68 second trimester and 54 third trimester fetal autopsies, at least 1 probable COD was identified in 59/68 (87%) second trimester and 44/54 (81%) third trimester cases. 42/68 (62%) second trimester and 28/54 (52%) third trimester fetuses had probable COD secondary to placental pathology. Among placental causes, 29/42 (69%) second trimester and 14/28 (50%) third trimester stillbirths were related to compromised fetal microcirculation with umbilical cord abnormality.

CONCLUSIONS

Among stillborn first and second trimester fetuses who undergo autopsy, the most prevalent COD is pathologic placental conditions, particularly those associated with umbilical cord obstruction. This study stresses the importance of placenta examination for establishing COD in both second and third trimester fetuses.

Recasting Current Knowledge of Human Fetal Circulation: The Importance of Computational Models

Computational hemodynamic simulations are becoming increasingly important for cardiovascular research and clinical practice, yet incorporating numerical simulations of human fetal circulation is relatively underutilized and underdeveloped. The fetus possesses unique vascular shunts to appropriately distribute oxygen and nutrients acquired from the placenta, adding complexity and adaptability to blood flow patterns within the fetal vascular network. Perturbations to fetal circulation compromise fetal growth and trigger the abnormal cardiovascular remodeling that underlies congenital heart defects. Computational modeling can be used to elucidate complex blood flow patterns in the fetal circulatory system for normal versus abnormal development. We present an overview of fetal cardiovascular physiology and its evolution from being investigated with invasive experiments and primitive imaging techniques to advanced imaging (4D MRI and ultrasound) and computational modeling. We introduce the theoretical backgrounds of both lumped-parameter networks and three-dimensional computational fluid dynamic simulations of the cardiovascular system. We subsequently summarize existing modeling studies of human fetal circulation along with their limitations and challenges. Finally, we highlight opportunities for improved fetal circulation models.

Sonographic evaluation of umbilical cord thickness in monochorionic diamniotic twin pregnancies

OBJECTIVE

To develop a nomogram of the thickness of the umbilical cord (UC) and its components in monochorionic diamniotic (MCDA) twin pregnancies.

METHODS

This prospective longitudinal study involved 47 MCDA twin pregnancies (94 fetuses) between 18 and 33 weeks of gestation. Ultrasound assessments of UC cross-sections and measurements of the umbilical cord area (UCA), the umbilical vein area (UVA), the umbilical artery area (UAA), and the Wharton jelly area (WJA) were made. The UC measurements were correlated with gestational ages. Reference values for the gestational ages of MCDA pregnancies were determined and compared with those of dichorionic twins and singletons. The cases which developed selective intrauterine growth restriction were contrasted with normal cases.

RESULTS

A positive correlation was found between all UC components and gestational age and fetal weight. The UCA of MCDA fetuses was significantly larger than that of DC fetuses (P < 0.001) at the expense of a larger WJA (P < 0.001) and similar to that of singleton pregnancies. The MCDA fetuses with an estimated fetal weight below the 10th percentile had a smaller UCA than fetuses with a normal estimated weight (P < 0.001).

CONCLUSION

The MCDA twins exhibited a thicker UC than that of dichorionic twins. This article is protected by copyright. All rights reserved.

Absence of Wharton's Jelly at the Abdominal Site of the Umbilical Cord Insertion. Rare Case Report and Review of the Literature

Wharton’s jelly is a specialized connective tissue surrounding and protecting umbilical cord vessels. In its absence, the vessels are exposed to the risk of compression or rupture. Because the condition is very rare and there are no available antepartum investigation methods for diagnosis, these cases are usually discovered after delivery, frequently after in utero fetal demise. We report the fortunate case of a 29-year-old nulliparous woman, with an uncomplicated pregnancy, admitted at 39 weeks in labor where a persistently abnormal cardiotocographic trace led to delivery by cesarean section of a healthy 3500 g newborn. After delivery, a Wharton’s jelly anomaly was identified at the abdominal umbilical insertion (umbilical cord vessels, approximately 1 cm in length, were completely uncovered by Wharton’s jelly), which required surgical thread elective ligation. In the presence of a persistently abnormal CTG trace, in a pregnancy with no clinical settings suggestive of either chronic or acute fetal hypoxemia, the absence of Wharton’s jelly should be taken into consideration in the differential diagnosis.

Current Perspectives of Prenatal Sonography of Umbilical Cord Morphology

The umbilical cord constitutes a continuation of the fetal cardiovascular system anatomically bridging between the placenta and the fetus. This structure, critical in human development, enables mobility of the developing fetus within the gestational sac in contrast to the placenta, which is anchored to the uterine wall. The umbilical cord is protected by unique, robust anatomical features, which include: length of the umbilical cord, Wharton’s jelly, two umbilical arteries, coiling, and suspension in amniotic fluid. These features all contribute to protect and buffer this essential structure from potential detrimental twisting, shearing, torsion, and compression forces throughout gestation, and specifically during labor and delivery. The arterial components of the umbilical cord are further protected by the presence of Hyrtl’s anastomosis between the two respective umbilical arteries. Abnormalities of the umbilical cord are uncommon yet include excessively long or short cords, hyper or hypocoiling, cysts, single umbilical artery, supernumerary vessels, rarely an absent umbilical cord, stricture, furcate and velamentous insertions (including vasa previa), umbilical vein and arterial thrombosis, umbilical artery aneurysm, hematomas, and tumors (including hemangioma angiomyxoma and teratoma). This commentary will address current perspectives of prenatal sonography of the umbilical cord, including structural anomalies and the potential impact of future imaging technologies.

Unusual umbilical Doppler waveform and fetal distress likely due to hypercoiled cord

Both reduced and increased umbilical cord coiling patterns have been associated with fetal distress and adverse perinatal outcomes, including fetal death. Prenatal diagnosis of cord coiling anomalies is challenging but potentially very useful for identifying those that may benefit from a more intensive monitoring. Nevertheless, there is no standardized approach for this potentially lethal complication when suspected. We report a case of fetal Doppler alterations and cardiotocographic anomalies likely due to hypercoiled cord in a 29-week primigravida referred to our clinic, who therefore underwent an emergency cesarean section. This case could help clinicians to consider cord anomalies as a possible cause of fetal distress.

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 characteristics and their association with adverse pregnancy outcomes: A systematic review and meta-analysis

OBJECTIVE

Current data on the role of the umbilical cord in pregnancy complications are conflicting; estimates of the proportion of stillbirths due to cord problems range from 3.4 to 26.7%. A systematic review and meta-analysis were undertaken to determine which umbilical cord abnormalities are associated with stillbirth and related adverse pregnancy outcomes.

METHODS

MEDLINE, EMBASE, CINAHL and Google Scholar were searched from 1960 to present day. Reference lists of included studies and grey literature were also searched. Cohort, cross-sectional, or case-control studies of singleton pregnancies after 20 weeks' gestation that reported the frequency of umbilical cord characteristics or cord abnormalities and their relationship to stillbirth or other adverse outcomes were included. Quality of included studies was assessed using NIH quality assessment tools. Analyses were performed in STATA.

RESULTS

This review included 145 studies. Nuchal cords were present in 22% of births (95% CI 19, 25); multiple loops of cord were present in 4% (95% CI 3, 5) and true knots of the cord in 1% (95% CI 0, 1) of births. There was no evidence for an association between stillbirth and any nuchal cord (OR 1.11, 95% CI 0.62, 1.98). Comparing multiple loops of nuchal cord to single loops or no loop gave an OR of 2.36 (95% CI 0.99, 5.62). We were not able to look at the effect of tight or loose nuchal loops. The likelihood of stillbirth was significantly higher with a true cord knot (OR 4.65, 95% CI 2.09, 10.37).

CONCLUSIONS

True umbilical cord knots are associated with increased risk of stillbirth; the incidence of stillbirth is higher with multiple nuchal loops compared to single nuchal cords. No studies reported the combined effects of multiple umbilical cord abnormalities. Our analyses suggest specific avenues for future research.

Pathoanatomical Lesions in Placentas With Excessively Hypercoiled Umbilical Cords: Frequent Detection of Massive Perivillous Fibrin Deposition

This study focused to investigate a possible association of extensive umbilical hypercoiling (displaying an umbilical coiling index [UCI] of at least 1.0 coils/cm), clinical outcome, and associated pathoanatomical placental lesions. Of the 771 singleton placentas from the second and third trimesters submitted for pathoanatomical evaluation, 15 cases (2%) displayed extensive hypercoiling. There was an association of excessive hypercoiling with hypotrophy of fetuses and children (11 cases) and fetal demise (12 cases). Thin cord syndrome and umbilical stricture were observed in 9 cases and 4 cases, respectively. Seven of the 15 cases with excessive umbilical hypercoiling showed increased placental fibrin deposition (47% of the cases with hypercoiling), in 4 cases sufficient for rendering the diagnosis of massive perivillous fibrin deposition. Signs of maternal vascular malperfusion (n = 6) and chorangiosis (n = 2) were also detected in cases with hypercoiling. Recurrence of excessive umbilical hypercoiling was observed in 2 families, suggesting a genetic predisposition for the development of this lesion. Extensive hypercoiling could be a hitherto underrecognized pathogenetic factor for the development of massive perivillous fibrin deposition. A high UCI measured in the second trimester by ultrasound may be predictive of fetal hypotrophy, and intensified fetal monitoring is warranted, particularly if there is a history of hypercoiling and adverse fetal outcome.

Second-trimester fetal autopsy: A morphological study with prenatal USG correlations and clinical implications

OBJECTIVES:

The objective of this study is to analyze the second-trimester fetal autopsies and to reemphasize the role of autopsy by comparing autopsy findings with prenatal ultrasound observations.

MATERIALS AND METHODS:

Retrospective analysis of second-trimester fetal autopsies over a period of 7.5 years (January 2009–June 2016). A standard protocol of autopsy procedure was followed, which included external examination with photography, X-ray, internal examination, and histopathological examination. In fetuses with congenital malformations (CMs), the findings of prenatal ultrasonogram and autopsy examination were compared.

RESULTS:

We analyzed a total of 66 fetuses, which includes 17 intrauterine fetal death, 49 terminations for CM, and increased risk for chromosomal abnormality. In fetuses with CM, multiple anomalies were more common than a single anomaly. The most common anomalies were seen involving central nervous system (neural tube defect) followed by the genitourinary system. Autopsy confirmed prenatal ultrasound findings in all cases except three. Complete agreement between USG findings and autopsy were seen in 17 cases (39.7%). Additional findings on autopsy were noted in 25 cases (62.2%). Among these, 15 cases had a significant change of recurrence risk due to altered initial ultrasound diagnosis.

CONCLUSION:

Fetal autopsy plays an important role in arriving at the final diagnosis and detecting the cause of death. This information is very essential for the clinicians, in genetic counseling of the parents, and management of future pregnancies.

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.

The biomechanics of the umbilical cord Wharton Jelly: Roles in hemodynamic proficiency and resistance to compression

The umbilical cord is a complex structure containing three vessels, one straight vein and two coiled arteries, encased by the Wharton Jelly (WJ) a spongy structure made of collagen and hydrated macromolecules. Fetal blood reaches the placenta through the arteries and flows back to the fetus through the vein. The role of the WJ in maintaining cord circulation proficiency and the ultimate reason for arterial coiling still lack of reasonable mechanistic interpretations. We performed biaxial tension tests and evidenced significant differences in the mechanical properties of the core and peripheral WJ. The core region, located between the arteries and the vein, resulted rather stiffer close to the fetus. Finite element modelling and optimization based inverse method were used to create 2D and 3D models of the cord and to simulate stress distribution in different hemodynamic conditions, compressive loads and arterial coiling. We recorded a facilitated stress transmission from the arteries to the vein through the soft core of periplacental WJ. This condition generates a pressure gradient that boosts the venous backflow circulation towards the fetus. Peripheral WJ allows arteries to act as pressure buffering chambers during the cardiac diastole and helps to dissipate compressive forces away from vessels. Altered WJ biomechanics may represent the structural basis of cord vulnerability in many high-risk clinical conditions.

Risk factors of stillbirth in Yemen

BACKGROUND

Yemen has the highest stillbirth rate among the Arab countries. However, the risk factors of this high rate are lacking. This study aimed to determine the maternal, newborn, and service related risk factors for stillbirths at the main maternity hospital in Sana'a city.

METHODS

A case-control study was conducted in the main maternity hospital in Sana'a city, Yemen. Case and controls were selected prospectively during the study period. Cases were women who delivered stillbirths after 24 weeks of gestation. Risk factors data for mothers and their neonates were collected using face-to-face interview and data abstraction from medical records.

RESULTS

The study included 101 women with stillbirths and 202 women with singleton live births. Mothers older than 35 years (Odds ratio (OR) = 4.9) and those with low level of education were significantly more likely to give stillbirths. Prolonged labor (OR = 5.8), mothers' anemia (OR = 2.1), less than 4 antenatal visits (OR = 5.1) and meconium stained amniotic fluid (OR = 11.5) were significantly associated with increased odds of stillbirth. Prematurity (OR = 27), umbilical complications (OR = 6.4), low birth weight (OR = 17.7), and congenital complications (OR = 40.6) were significantly associated with higher odds of stillbirths.

CONCLUSIONS

This study identified many risk factors of stillbirth that are amenable to intervention. Encouraging women to deliver at health facilities, providing better management of obstetrical complications, proper antenatal care, and prompt referral services are essential for reduction of stillbirths in Yemen.

Fetal vascular malperfusion, an update

Fetal vascular malperfusion is the most recent term applied to a group of placental lesions indicating reduced or absent perfusion of the villous parenchyma by the fetus. The most common etiology of malperfusion is umbilical cord obstruction leading to stasis, ischemia, and in some cases thrombosis. Other contributing factors may include maternal diabetes, fetal cardiac insufficiency or hyperviscosity, and inherited or acquired thrombophilias. Severe or high grade fetal vascular malperfusion is an important risk factor for adverse pregnancy outcomes including fetal growth restriction, fetal CNS injury, and stillbirth. Overall recurrence risk for subsequent pregnancies is low.

An observation of umbilical coiling index in a low risk population in Nigeria

OBJECTIVES

The umbilical coiling index (UCI) is one of cord parameters for foetal assessment with limited studies in our environment. With recent advances in its evaluation, its significance, pattern, abnormalities and correlates need to be defined in our parturients.

METHODS

The umbilical cords of 436 neonates were examined. Gross examination was done within 5 min of delivery. The UCI was defined as the number of complete coils per centimetre of cord. Normal UCI was defined as values between the 10th and 90th percentiles of the study population.

RESULTS

The mean umbilical cord length was 52.7±11.5 cm, mean number of coils was 10.8±5.1 and mean UCI was 0.21±0.099. The range was between 0.0 and 1.0. UCI values of 0.13 and 0.30 were 10th and 90th percentiles, respectively. Normal UCI was observed in 351 (80.5%) neonates, 44 (10.4%) and 41 (9.1%) had hypo- and hypercoiled cords, respectively. Congenital abnormalities occurred in the normocoiled and hypercoiled groups but was not demonstrated in the hypocoiled group. The mean value of UCI in neonates with congenital abnormalities was 0.29±0.12 (P=0.011). There was no significant statistical relationship between foetal outcome and degree of UCI.

CONCLUSION

The UCI was not associated with adverse perinatal outcome in this study.

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.

Association of coexisting morphological umbilical cord abnormality and clinical cord compromise with hypoxic and thrombotic placental histology

To assess the usefulness and limitations of placental histology when morphological umbilical cord (UC) abnormality coexists with clinical UC compromise, 5634 consecutive placentas were divided into four groups and statistically compared: group 1-182 placentas from pregnancies with clinical features of UC compromise (variable decelerations, UC entanglement, prolapse, or true knot at delivery); group 2-1355 placentas with abnormal UC morphology or insertion; group 3-152 placentas with at least one phenotype from group 1 and one from group 2; group 4-3945 placentas with no clinical or morphological UC-related phenotypes (control group).Differences were analyzed by ANOVA or χ (2). Of 68 phenotypes studied, 13 clinical and 18 placental phenotypes were statistically significant. In group 1, 2 phenotypes were most common (oligohydramnios and abnormal fetal heart rate tracing). In group 2, 6 phenotypes were most common, including 4 clinical (abnormal umbilical artery Dopplers, nonmacerated stillbirth, multiple pregnancy, and fetal growth restriction) and 2 placental. In group 3, 23 phenotypes were most common, including 7 clinical (gestational hypertension, polyhydramnios, induction of labor, cesarean section, macerated stillbirth, congenital malformations, and abnormal 3rd stage of labor) and 16 placental. The existence of clinical signs of UC compromise alone was associated with the absence of pathomorphological placental abnormalities. However, the coexistence of clinical and abnormal morphological UC phenotypes was statistically significantly associated with placental histological signs of decreased fetal blood flow, hypoxia (acute and chronic post uterine), shallow placental implantation, and/or amnion nodosum. Thus, confirmation of clinical UC compromise should not be expected on placental examination if no morphological UC abnormality or abnormal UC insertion has been found.

Major risk factors for stillbirth in different trimesters of pregnancy--a systematic review

Stillbirth remains an event that has an important impact on global health issues. Different levels of health care between countries suggest that the stillbirth rate may be one of the indicators of the quality of a country's medical system. In this review, major risk factors for stillbirth will be discussed, especially in different trimesters of pregnancy. Early identification of risk factors for stillbirth and appropriate antenatal management may reduce preventable stillbirths and improve general outcomes of pregnancy.

Umbilical hypercoiling in 2nd- and 3rd-trimester intrauterine fetal death

Cases of unexplained intrauterine fetal death (IUFD) can be reduced by full placental examination, with or without autopsy. Determination of the umbilical coiling index (UCI) is considered to be a part of full placental examination. Umbilical hypercoiling (UCI above 0.30 coils/cm) is associated with IUFD. In a large retrospective study, we found an incidence of 18% umbilical hypercoiling in IUFD. We explored the association between umbilical hypercoiling and 2nd- and 3rd-trimester IUFD in 77 cases. There was a significant negative correlation between the UCI and gestational age of IUFD (P<0.001). More severe cases of hypercoiling were observed in the categories of IUFD at a younger age and with a longer duration. Signs of fetal thrombosis were significantly more present in IUFDs with umbilical hypercoiling. An umbilical cord stricture and hypercoiling seem to be significantly more common in IUFD. The severity of hypercoiling was of no influence on the presence or absence of an umbilical cord stricture. Furthermore, there was no significant difference in signs of cardiac failure between the groups of IUFD with and without umbilical hypercoiling. Our findings may be explained by the theory that hypercoiling leads to a disturbed fetal-placental circulation. Therefore, determination of the UCI should be part of the routine placental examination of cases of IUFD.

Pathology of the stillborn infant for the general pathologist: part 1

As the information obtained from previable fetal and stillbirth autopsies is used not only to explain the loss to the parents, but for future pregnancy planning, general pathologists need to be comfortable in dealing with these autopsies. The importance of an adequate fetal examination has been emphasized in a recent policy on the subject by the American Board of Pathology http://www.abpath.org/FetalAutopsyPolicy.pdf. This review paper covers the approach to the fetal and stillbirth autopsy. This first article covers the approach to the nonanomalous and anomalous autopsy. Hydrops fetalis will be covered in the second part of this series to be published subsequently.

Fetal demise due to cord entanglement in the early second trimester

In this report, we describe a rare cause of in utero fetal death, a complex entanglement of the umbilical cord around the fetal neck. At the 16th gestational week of pregnancy, routine fetal ultrasonography showed no fetal heartbeat. Thereafter, the fetus was delivered vaginally in the breech presentation. The neck was found to be encircled by multiple tight loops of the umbilical cord. Other than a thin and elongated neck, there were no dysmorphic features and no chromosomal abnormality on cytogenetic analysis.

Umbilical artery thrombosis is a rare but clinically important finding: a series of 7 cases with clinical outcomes

Umbilical artery thrombosis is a rare occurrence and is associated with poor neonatal outcomes. We present a series of 7 cases occurring over a 13-year period. The National Maternity Hospital is a tertiary referral center with approximately 10,000 births per annum. Cases were identified by a keyword search on the laboratory computer system. Seven cases were retrieved over a 13-year period (from an estimated 116,000 births): 5 cases from 7306 placentas and 2 cases from 1174 autopsies performed. Only cases with isolated umbilical artery thrombosis were included in the study. Placental histology from all cases was examined, placental gross findings were recorded, and clinical information and Doppler findings were obtained. Two infants were stillborn, and an additional 3 of the 7 cases were small for dates. All liveborn infants had a complicated neonatal course: 1 infant had a caudate infarction, 1 was born with partial acrania and schizencephaly, and 1 had a prolonged intensive care unit admission for low birth weight and jaundice. One case had absent end diastolic flow on Doppler ultrasound. Three cases had a cord diameter narrower than that expected for gestational age. All cases showed evidence of placental hypoperfusion. Umbilical artery thrombosis is a rare occurrence and carries a poor prognosis.

Umbilical Cord Pathology

Problems and abnormalities of the umbilical cord play a significant role in perinatal morbidity and mortality. Because the umbilical cord is the lifeline of the fetus, any disruption of blood flow through the umbilical vessels can lead to severe fetal consequences.

Gross umbilical cord complications are associated with placental lesions of circulatory stasis and fetal hypoxia

Umbilical cord complications (UCC), such as true knots (TK), velamentous (VEL) insertion, marginal umbilical cord (MUC) insertion, umbilical cord entanglement (UCE) (both nuchal and non-nuchal), excessively long umbilical cord (ELUC), and excessively twisted umbilical cord (ETUC), can lead to decreased UC blood flow and have been associated with adverse fetal outcome and intrauterine fetal demise (IUFD). Few large series exist that correlate UCC with specific pathologic findings of the placenta. We present the largest series of UCC at this time. Eight hundred forty-one 3rd-trimester placentas with UCC were identified, as well as 858 randomly selected gestational age-matched placentas with grossly unremarkable UC. Lesions associated with circulatory stasis and thrombosis, including villous capillary congestion (VC), umbilical vessel distension (UVD), chorionic plate vessel distension (CPD), umbilical vessel thrombosis (UVT), fetal vascular thrombosis (FVT), intimal fibrin cushions (IFC), and avascular villi (AV), were noted, as well as other pathologic lesions. Data were analyzed by analysis of variance and Fisher exact tests, with P < 0.05 statistically significant. Umbilical cord complications as a group was associated with a significant increase in placental circulatory stasis lesions. Lesions associated with hypoxia, namely nucleated red blood cells and chorangiosis, were also increased. Finally, the presence of any UCC was significantly associated with IUFD. We also found that multiple UCC are associated with nonreassuring fetal heart rate and chorangiosis but that the presence of a single UCC was not. This indicates that UCC may lead to intrauterine hypoxia and subsequent adverse fetal outcome and that multiple UCC may be cumulative in effect.

Factors contributing to intra-uterine fetal death

PURPOSE

We aimed in this research to explore factors contributing to the occurrence of intra-uterine fetal death (IUFD).

METHODS

The study was conducted between 1st January 2008 and 31st December 2009 in the Department of Obstetrics and Gynecology at King Abdulaziz Medical City, Riyadh, Saudi Arabia. Patients who were diagnosed to have IUFD at ≥24 weeks of gestation and those whose dead fetuses were found to weigh ≥500 g after delivery were eligible to be included. 138 patients with IUFD and 237 controls with alive fetuses were enrolled. Data were collected from printed and computerized medical records of participants. Factors that may have contributed to the occurrence of IUFD were explored. Comparisons between various risk factors and outcomes of the two groups were done. p value was statistically significant if ≤0.05.

RESULTS

Patients who did not receive antenatal care (ANC) services are at 70 % increased risk for developing IUFD (OR 0.31, p < 0.0001). Risk of IUFD increases 25-fold with the occurrence of abruption placenta (OR 25.81, p ≤ 0.0001), tenfolds with the occurrence of intra-uterine growth restrictions (OR 10.78, p = 0.04) and threefolds with the presence of hypertensive disorder in pregnancy (OR 3.17, p = 0.04). Finally, patients carrying IUFD fetuses are at higher risk to develop labor complications compared with their controls (p ≤ 0.0001).

CONCLUSION

Despite the difficulty in predicting IUFD occurrence, it appears that carefully implemented ANC and timely management of at risk patients may contribute to its prevention.

Immunomodulatory effect of human umbilical cord Wharton's jelly-derived mesenchymal stem cells on lymphocytes

Studies have shown that mesenchymal stem cells (MSCs) have low immunogenicity and immune regulation. Human umbilical cord Wharton's jelly provides a new source for MSCs that are highly proliferative and have multi-differentiation potential. To investigate immunomodulatory effects of human Wharton's jelly cells (WJCs) on lymphocytes, we successfully isolated MSCs from human umbilical cord Wharton's jelly. WJCs expressed MSC markers but low levels of human leukocyte antigen (HLA)-ABC and no HLA-DR. These results indicate that WJCs have low immunogenicity. Both WJCs and their culture supernatant could inhibit the proliferation of phytohemagglutinin-stimulated human peripheral blood lymphocytes and mouse splenocytes. Additionally, WJCs suppressed secretion of transforming growth factor-β1 and interferon-γ by human peripheral blood lymphocytes. We conclude that the immunomodulatory effect of WJCs may be related to direct cell contact and inhibition of cytokine secretion by human peripheral blood lymphocytes.

Umbilical cord stricture is not a genetic anomaly: a study in twins

Two recent reports on recurrent cases of umbilical cord stricture (UCS) have opened the debate on the possibility of a genetic basis for this anomaly, traditionally considered to be sporadic. We present a series of 130 cases of UCS located at the fetal insertion, diagnosed among 2067 fetal and infantile autopsies performed during the last 10 years. All cases were macerated stillborn fetuses, and 54.6% were < or =20 weeks of gestational age. Our study is focused on 2 recurrent episodes and 16 cases occurring in multiple pregnancies. Among twins, males were affected more than females (2.2:1), although no statistical significance was found. Associated umbilical cord anomalies were present in 8 of 16 cases, consisting of hypocoiling (3 cases), hypercoiling (2 cases), excessive length (1 case), vascular tortuosity (1 case), and single umbilical artery (1 case). The most frequent placental finding was obliterative endovasculopathy (6 cases), probably indicating a causal relationship with UCS. Zygosity was analyzed by placental histology and/or a panel of 12 microsatellite markers to classify twins as monozygotic (8 cases) or dizygotic (8 cases). Our data prove that UCS is not a genetic condition because all 8 genetically identical twins were discordant for the anomaly and 2 dizygotic twins with UCS had co-twins also affected. Genetic factors are not implicated in UCS pathophysiology, and parents with a fetal demise due to UCS should be counseled as having a low-recurrence risk for subsequent pregnancies. Because there is not a higher incidence of UCS in multiple gestations, twinning should not be considered a risk factor for UCS.

The placenta as witness

The placenta not only "records" and reflects the intrauterine environment, it also provides valuable information on the cause and timing of many adverse events and conditions. The placenta may be useful in several ways. It may be the cause of injury due to an inherent abnormality, it may "malfunction" because of disease processes that are not primarily placental in origin, or it may merely reflect an abnormal intrauterine environment. Not only may the etiology of the injury be ascertained from placental examination, but also a time frame during which the abnormal condition has been operating. Acute lesions may be associated with sudden catastrophic events, whereas other, more chronic lesions lead to decreased placental reserves. Markedly depleted reserves will render the infant susceptible to other, sometimes more acute, events and thus are also associated with significant injury or even death.

Concise review: human umbilical cord stroma with regard to the source of fetus-derived stem cells

Human umbilical cord (UC) has been a tissue of increasing interest in recent years. Many groups have shown the stem cell potency of stromal cells isolated from the human UC mesenchymal tissue, namely, Wharton's jelly. Since UC is a postnatal organ discarded after birth, the collection of cells does not require an invasive procedure with ethical concerns. Stromal cells, as the dominant cells of this fetus-derived tissue, possess multipotent properties between embryonic stem cells and adult stem cells. They bear a relatively higher proliferation rate and self-renewal capacity. Although they share common surface markers with bone marrow-derived MSCs, they also express certain embryonic stem cell markers, albeit in low levels. Without any spontaneous differentiation, they can be successfully differentiated into mature adipocytes, osteoblasts, chondrocytes, skeletal myocytes, cardiomyocytes, neurons, and endothelial cells. While causing no immunorejection reaction, they effectively function in vivo as dopaminergic neurons, myocytes, and endothelial cells. Given these characteristics, particularly the plasticity and developmental flexibility, UC stromal cells are now considered an alternative source of stem cells and deserve to be examined in long-term clinical trials. This review first aims to document the published findings so far regarding the nature of human UC stroma with special emphasis on the spatial distribution and functional structure of stromal cells and matrix, which serves as a niche for residing cells, and, secondly, to assess the in vitro and in vivo experiments in which differential stem cell potencies were evaluated.

Cord abnormalities, structural lesions, and cord “accidents”

As the umbilical cord is the lifeline of the fetus, obstruction or disruption of blood flow through the umbilical vessels can lead to severe fetal compromise. Obstruction is usually mechanical in nature and is associated with compression of the umbilical cord and umbilical vessels. Disruption of umbilical or fetal vessels is usually traumatic in origin. These conditions have in common a loss of blood flow to the fetus and an association with adverse perinatal outcome.