The umbilical coiling index in complicated pregnancy

Prediction of postnatal abnormal umbilical cord coiling by antenatal evaluation in pregnant women: Diagnostic accuracy study; a systematic review

STUDY OBJECTIVE

Umbilical cord abnormalities increase neonatal morbidity and mortality. Considering uncertainties about the best time of an antenatal ultrasonography scan to evaluate the umbilical coiling index (UCI), this systematic review was designed to assess the diagnostic accuracy value of antenatal ultrasound assessments to predict abnormal postpartum UCI.

METHODS

All observational, cross-sectional, case-control, cohort, and diagnostic accuracy studies up to March 26, 2022, were searched and assessed according to PRISMA guidelines in Ovid, Cochrane, Scopus, PubMed, Web of Science, Embase, Proquest, Science Direct, and Clinical Key databases, and Google Scholar search engine.

RESULTS

The total number of 63 190 documents were retrieved from databases. The duplicates (19 272) were removed, 43 918 articles were screened for relevance, and 56 papers were selected for full-text evaluation, resulting in 14 qualified pieces subjected to the quality CASP tools for each type of study. Finally, six articles were evaluated, extracted, and confirmed. Overall, we had 16 evaluations (11 normal pregnancies, 4 gestational diabetes mellitus, and 1 group at risk for small gestational age), from which 9 and 7 were respectively performed in the second and third trimesters. Most of the evaluations considered both hypocoiling and hypercoiling. The sensitivity, specificity, and area under curves (AUCs) change range between the evaluations were 0.09-0.97, 0.59-0.96, and 0.262-0.84, respectively.

CONCLUSION

Observing any coiling abnormalities in every trimester, both the second and third, is highly sensitive to predicting abnormal postnatal UCI (pUCI). Conclusively, any detected antenatal abnormality is worth attention. Both trimesters' evaluations are essential, and no superiority is seen for any of them. The systematic review revealed statistical and clinical heterogeneity; a meta-analysis was impossible.

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.

Placental pathology findings in perinatal deaths from 28 weeks gestation in Aotearoa New Zealand

INTRODUCTION

Women of South Asian ethnicity are overrepresented in adverse pregnancy outcome across high-income countries, including those related to placental dysfunction. It has been hypothesised that placental aging occurs at earlier gestation in South Asian pregnancies. We aimed to identify differences in placental pathology among perinatal deaths ≥28 weeks gestation, between South Asian, Māori and New Zealand (NZ) European women in Aotearoa NZ, with a focus on women of South Asian ethnicity.

METHODS

Placental pathology reports and clinical data from perinatal deaths between 2008 and 2017 were provided by the NZ Perinatal and Maternal Mortality Review Committee, blinded, and analysed by an experienced perinatal pathologist using the Amsterdam Placental Workshop Group Consensus Statement criteria.

RESULTS

790 of 1161 placental pathology reports, 346 preterm (28⁺⁰ to 36⁺⁶ weeks) and 444 term (≥37⁺⁰ weeks) deaths, met the inclusion criteria. Among preterm deaths, South Asian women had higher rates of maternal vascular malperfusion compared with Māori (aOR 4.16, 95%CI 1.55-11.15) and NZ European (aOR 2.60, 95%CI 1.10-6.16). Among term deaths, South Asian women had higher rates of abnormal villous morphology compared with Māori (aOR 2.19, 95%CI 1.04-4.62) and NZ European (aOR 2.12, 95%CI 1.14-3.94), mostly due to increased rates of chorangiosis (36.7%, compared to 23.3% and 21.7%, respectively).

DISCUSSION

Differences in placental pathology by ethnicity were observed among preterm and term perinatal deaths. While we suspect differing underlying causal pathways, these deaths may be associated with maternal diabetic and red blood cell disorders among South Asian women, leading to a hypoxic state in-utero.

A Longitudinal Analytical Study on Umbilical Cord Coiling Index as a Predictor of Pregnancy Outcome

Background The umbilical cord coiling index (UCI) is usually measured sonographically during antenatal follow-up and can be used to determine the fetuses at risk of adverse outcomes. Methodology UCI measured antenatally and postnatally whose correlation is studied along with the association of abnormal UCI with the adverse outcomes in terms of gestational age, intrauterine growth restriction (IUGR), intra-uterine death, birth weight, sex, neonatal intensive care unit (NICU) admission, the color of the liquor, Amniotic Fluid Index (AFI), Appearance, Pulse, Grimace, Activity, and Respiration (APGAR) score at one min and five mins and mode of delivery. All parameters are tested for significant differences among UCI and a p-value < 0.05 is considered significant. The correlation of UCI measured antenatally and postnatally is tested using the spearman correlation coefficient. Results A strong correlation is found between antenatal UCI and postnatal UCI with r_s 0.9. The majority of the population had normo coiling. Hyper and hypo coiling are associated risks of emergency lower segment cesarean section (LSCS). Low birth weight is seen in 88.89% of hypo coiled patients with a p-value < 0.01. The coiling index among sex is found to be insignificant with a p-value of 0.81. Meconium-Stained Liquor (MSL) is seen in 78.5% of hyper coiled patients. IUGR is found to be associated with hypo coiling as seen in 59.2% of patients with significant p-value (< 0.01). Age, gestational age, and birth weight are found to be statistically significant between various coiling indexes with p-value < 0.05. Conclusion Antenatal UCI correlates with postnatal UCI and any abnormal index found can be used as a predictor of adverse perinatal outcomes and help obstetricians to monitor continuously and put the patients at risk on prophylactic measures.

Factors related to morbidity and maternal and perinatal outcomes of umbilical cord torsion

Objective

This study analyzed factors influencing umbilical cord torsion, measured the umbilical coiling index (UCI) postnatally, and analyzed the association of umbilical cord torsion with maternal and perinatal outcomes.

Methods

In total, 845 antenatal women who went into labor at the Fujian Provincial Maternity and Children’s Hospital from January 2016 to January 2017 were retrospectively studied. The patients were divided into those with and without umbilical cord torsion. Possible influencing factors and the UCI were noted, and maternal and perinatal outcomes were compared.

Results

Higher morbidity in the presence of umbilical cord torsion was affected by multiparous pregnancy and a long cord. The area under the curve was 0.666 for the UCI to predict fetal distress and 0.505 for the umbilical artery peak systolic to end diastolic flow velocity ratio (S/D ratio) to predict fetal distress. Umbilical cord torsion was associated with higher rates of fetal distress, forceps-assisted delivery, cesarean sections, fetal heart rate abnormalities, amniotic fluid meconium staining, neonatal intensive care unit admission, and small for gestational age.

Conclusions

Multiparous status and longer umbilical cord length were highly associated with umbilical cord torsion. The UCI is a better predictor of fetal distress than is the umbilical artery S/D ratio.

Umbilical cord coiling index for the prediction of adverse pregnancy outcomes: a meta-analysis and sequential analysis

Purpose: To evaluate the potential association of abnormal cord coiling with adverse pregnancy outcomes.Materials and methods: We used the Medline (1966-2018), Scopus (2004-2018), Clinicaltrials.gov (2008-2018), Embase (1980-2018), Cochrane Central Register of Controlled Trials CENTRAL (1999-2018), and Google Scholar (2004-2018) databases. The date of last search was set on 31 May 2018. Language, country, or date restrictions were not applied during the literature research to prevent bias. All observational (both prospective and retrospective) studies that reported maternal and neonatal antenatal and perinatal outcomes based on the umbilical coiling index (UCI) status were considered as eligible for inclusion. Meta-analysis of the risk ratio (RR) and mean differences (MD) among hypocoiled/hypercoiled and normocoiled cases was performed with RevMan 5.3 software. Univariate metaregression and leave-one-out meta-analysis was performed with Open Meta-Analyst statistical software. Trial sequential analysis was performed with the trial sequential analysis (TSA) software.Results: Twenty four studies were finally included that involved 9553 pregnant women. Umbilical cord coiling was evaluated with the use of the umbilical coiling index (UCI). Values of the UCI below the 10th percentile were evaluated as hypocoiled and above the 90th percentile as hypercoiled. Hypocoiled cords were significantly associated with increased prevalence of preterm birth < 37 weeks, need for interventional delivery due to fetal distress, meconium stained liquor, Apgar scores < 7 at 5 min, small for gestational age (SGA) neonates, fetal anomalies, need for admission in the neonatal intensive care unit (NICU), fetal heart rate abnormalities, and fetal death. Hypercoiled cords were significantly associated with increased prevalence of preterm birth < 37 weeks, need for interventional delivery due to fetal distress, meconium stained liquor, Apgar scores < 7 at 5 min, small for gestational age (SGA) neonates, fetal anomalies, fetal growth restriction fetal heart rate abnormalities, fetal acidosis, and fetal death.Conclusions: The findings of our meta-analysis underline the correlation of UCI abnormalities with antenatal and perinatal pathology. More studies are needed, however, to elucidate whether antenatal assessment of the UCI can be used as routine in clinical practice as well as its value in uncomplicated pregnancies.

Histomorphological changes of the placenta and umbilical cord in pregnancies complicated by gestational diabetes mellitus

INTRODUCTION

The objective of this study was to compare the histomorphological changes of placenta and umbilical cord (UC), between gestational diabetes mellitus (GDM) and non- GDM pregnancies.

METHODS

In this prospective study, 222 parturients were recruited (117 GDM and 105 non-GDM). GDM was confirmed at 24-28 weeks of gestation, using one-step strategy. A full record of demographic, laboratory, histologic and gross morphology data of placenta and UC was extracted and analyzed.

RESULTS

Overall, 222 placentas/UCs met inclusion criteria. The mean (SD) of gestational age of GDM diagnosis was 20.68 (10.02) and the GDM duration was 16.76 (8.98) weeks. The mean HbA1C was 6.03 (0.41) % in the GDM group. The gross morphology findings including UC diameter and thick edematous UC differed significantly between two groups and more presented in GDM group, 1.41 (0.03) vs. 1.28 (0.03) centimeters; p-value = 0.006 and 34.19% vs. 16.19%; p-value = 0.002, respectively. The umbilical coiling index (UCI) was similar in two groups (p-value = 0.61). In the histological evaluation, persistence of central vessels differed significantly between two groups, more detected in non-GDM (47.62% vs. 32.97%; p-value = 0.04). No other significant histomorphological changes were detected between two groups.

DISCUSSION

This study showed that gross morphologic features such as UC diameter increment and thick edematous UC happened more frequently, among the GDM parturients. Due to early diagnosis, diagnosis strategy, and optimal glycemic control, the histomorphological changes were less in GDM comparing of non-GDM group.

Disorders of placental villous maturation in fetal death

Objective The aims of this study were to ascertain the frequency of disorders of villous maturation in fetal death and to also delineate other placental histopathologic lesions in fetal death. Methods This was a retrospective observational cohort study of fetal deaths occurring among women between January 2004 and January 2016 at Hutzel Women's Hospital, Detroit, MI, USA. Cases comprised fetuses with death beyond 20 weeks' gestation. Fetal deaths with congenital anomalies and multiple gestations were excluded. Controls included pregnant women without medical/obstetrical complications and delivered singleton, term (37-42 weeks) neonate with 5-min Apgar score ≥7 and birthweight between the 10th and 90th percentiles. Results Ninety-two percent (132/143) of placentas with fetal death showed placental histologic lesions. Fetal deaths were associated with (1) higher frequency of disorders of villous maturation [44.0% (64/143) vs. 1.0% (4/405), P < 0.0001, prevalence ratio, 44.6; delayed villous maturation, 22% (31/143); accelerated villous maturation, 20% (28/143); and maturation arrest, 4% (5/143)]; (2) higher frequency of maternal vascular malperfusion lesions [75.5% (108/143) vs. 35.7% (337/944), P < 0.0001, prevalence ratio, 2.1] and fetal vascular malperfusion lesions [88.1% (126/143) vs. 19.7% (186/944), P < 0.0001, prevalence ratio, 4.5]; (3) higher frequency of placental histologic patterns suggestive of hypoxia [59.0% (85/143) vs. 9.3% (82/942), P < 0.0001, prevalence ratio, 6.8]; and (4) higher frequency of chronic inflammatory lesions [53.1% (76/143) vs. 29.9% (282/944), P < 0.001, prevalence ratio 1.8]. Conclusion This study demonstrates that placentas of women with fetal death were 44 times more likely to present disorders of villous maturation compared to placentas of those with normal pregnancy. This suggests that the burden of placental disorders of villous maturation lesions is substantial.

Variation of the maximum velocity along the umbilical vein supports the Reynolds pulsometer model

OBJECTIVE

To challenge, with a modern sonographic approach and a numerical model, the Reynolds's concept which suggests that the vascular structure of the umbilical cord could act as a pulsometer facilitating the venous return to the foetus.

METHOD

Forty-five patients between 20 and 28 weeks of gestation were included in the study. The blood maximum velocity in the umbilical vein, measured at both foetal and placental ends, was assessed. Several sonographic parameters of the cord, including the diameter of the umbilical vein at both extremities, cord cross-sectional area and Wharton's jelly section surface were measured. We compare our data with those of a numerical model.

RESULTS

A difference in maximum velocity between the two extremities of the umbilical vein (Δ^UVV_max) was noted. The maximum velocity was significantly higher at the foetal umbilical end (14.12 +/-3.18 cm/s) than at the placental end (11.93 +/-2.55 cm/s; p < 0.0001). The mean difference is 2.2 +/- 2.3 cm/s. No difference in the umbilical vein diameter was measured at both cord ends (umbilical 4.85 +/-0.9 mm, placental 4.86 +/-0.87 mm, p < 0.0001). There is no significant relationship between Δ^UVV_max and the cord cross-sectional area or Wharton's jelly index.

CONCLUSION

Modifications of the spatial velocity profile together with the pulsometer model could explain the maximum velocity changes that is measured in the umbilical vein along the cord. This numerical model consolidates the sonographic observations.

Gestational diabetes mellitus: the correlation between umbilical coiling index, and intrapartum as well as neonatal outcomes

Objectives

The objective of this study was to investigate the relationship between the postnatal umbilical coiling index (pUCI), and intrapartum and neonatal outcomes in parturients with gestational diabetes mellitus (GDM) and non-GDM.

Methods

An evaluation of the umbilical cords and pUCI of 117 neonates of GDM and 105 of non-GDM parturients were prospectively studied within 24 h after delivery. Furthermore, obstetric history, intrapartum and neonatal data were recorded.

Results

Premature rupture of membrane (PROM) (p = 0.001), emergency cesarean delivery (p = 0.01), spontaneous preterm delivery (p = 0.006), duration of hospital admission (p < 0.001), and congenital malformations (p = 0.03) were significantly higher in the GDM group. Moreover, pUCI had a significant association with large for gestational age (LGA) (p = 0.009), and meconium-stained amniotic fluid (p = 0.04) in the GDM group. In addition, increment of pUCI had significant association with spontaneous preterm delivery in both groups (p = 0.002) (OR = 1.23).

Conclusions

GDM is associated with spontaneous preterm delivery, PROM, emergency cesarean delivery, duration of hospital admission, and congenital malformations. Increase in pUCI could increase the rate of spontaneous preterm delivery in normal pregnancy and pregnancy complicated by GDM, as well as, the rate of LGA and meconium-stained amniotic fluid in GDM.

Antenatal umbilical coiling index in gestational diabetes mellitus and non-gestational diabetes pregnancy

OBJECTIVE

Umbilical cord abnormalities increase fetal morbidity and mortality. This study was designed to compare antenatal umbilical coiling index (aUCI) in gestational diabetes mellitus (GDM) and non-gestational diabetes mellitus (non-GDM) pregnancy, considering uncertainties about the best time to perform antenatal ultrasonography scan.

MATERIALS AND METHODS

In this prospective study, 246 parturients were included, 123 with GDM and 123 with non-GDM pregnancy. Gestational diabetes was confirmed at 24-28 weeks of gestation (WG) using one-step strategy. An anatomical ultrasound survey of placenta and umbilical cord was performed at 18-23 as well as 37-41 weeks of gestational age.

RESULTS

At 18-23 WG, the frequency distribution (10th, 90th percentiles, mean ± SD) of the aUCI in the GDM and non-GDM groups were (0.13,0.66,0.32 ± 0.19) and (0.18,0.74, 0.4 ± 0.31) respectively. These values were (0.12,0.4, 0.25 ± 0.11) in the GDM group at 37-41 WG and (0.17,0.43, 0.29 ± 0.11) in the non-GDM group. A significant relationship was detected between UCI value and GDM/non-GDM groups at both antenatal evaluations (18-23 WG; P = 0.002, 37-41WG; P < 0.001). A significant association at 18-23 WG was found between GDM/non-GDM groups and aUCI categorization (hypocoiling <10th, normocoiling 10th-90th and hypercoiling >90th) (P = 0.001). However, hypocoiling were significantly more frequent in GDM than non-GDM in both antenatal evaluations (P < 0.001, P = 0.006).

CONCLUSION

Antenatal UCI in pregnancy complicated by GDM were lower in comparison with non-GDM pregnancy. The most abnormal pattern of coiling in gestational diabetes was hypocoiling in both trimesters. In addition, 18-23 WG is the best time to perform ultrasound scan to detect aUCI and umbilical cord pattern.

Umbilical Cord Coiling in High-risk Pregnancies: Associations With Determinants of Adverse Birth Outcomes and Iron Status

Abnormal umbilical cord coiling has been associated with adverse neonatal outcomes, but the etiology of these findings remains poorly characterized. This study was undertaken to examine associations between cord coiling and maternal iron (Fe) status and to identify potential determinants of hypo- and hypercoiling in 2 higher risk obstetric groups: pregnant adolescents (≤18 years, n = 92) and adult women carrying twins (n = 49), triplets (n = 11), or quadruplets (n = 1). Umbilical cords were classified as hypo-, normo-, or hypercoiled using digital photographs to assess gross appearance. Hypocoiling and hypercoiling were observed in 44% (n = 86/195) and 13% (n = 26/195) of the combined study population. The prevalence of hypocoiling among women carrying multiples was over 3-fold higher than the prevalence in singleton pregnancies based on the published data. Within the entire study population, hypocoiling was associated with a lower gestational age at birth when compared to normocoiling and hypercoiling (36.3 ± 3.6 weeks [n = 86] vs 37.8 ± 2.7 [n = 83], P < .01, and 38.2 ± 2.6 [n = 26], P < .01, respectively), whereas hypercoiling was associated with significantly lower serum ferritin when compared to normocoiling ( P < .01) and hypocoiling ( P < .001). In the multiples cohort only, hypercoiling was significantly associated with multiparity ( P < .01) and lower birth weight ( P < .05). Further studies are needed to identify the determinants and consequences of cord coiling.

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.

Hypercoiling of the umbilical cord in uncomplicated singleton pregnancies

BACKGROUND

The umbilical coiling index (UCI) is a measure of the number of coils in the umbilical cord in relation to its length. Hypercoiled cords with a UCI of >0.3 coils/cm have been associated with adverse fetal and neonatal outcomes.

AIMS

The primary aim is to determine the accuracy of UCI measured on second trimester ultrasound in predicting UCI at birth. The secondary outcome is to investigate the association between hypercoiling of the umbilical cord on prenatal ultrasound and adverse maternal, fetal and neonatal outcomes.

METHODS

This was a prospective cohort study of uncomplicated singleton pregnancies. Seventy two patients were included in the study. UCI was measured in the second trimester ultrasound, and compared to UCI measured postnatally. Outcomes of patients with hypercoiled cords on ultrasound were compared to outcomes of patients with normocoiled cords.

RESULTS

Our results failed to show a strong correlation between the UCI determined with ultrasound, and the UCI determined with examination of the umbilical cord after delivery. We also did not demonstrate that measurement of the UCI on second trimester ultrasound is able to predict adverse maternal, fetal or neonatal outcomes.

CONCLUSION

This study suggests that measurement of the umbilical coiling index should not be part of routine second trimester sonography in patients with uncomplicated singleton pregnancies, with no other medical or surgical comorbidities.

Hypercoiled cord can cause a reversible abnormal Doppler in ductus venosus in cases of fetal growth restriction

AIM

Although an absent or reversed a-wave in ductus venosus (DV-RAV) is reported to be the terminal finding of fetal growth restriction (FGR), we have seen DV-RAV that disappears within a short span of time in some FGR cases with a hypercoiled cord. The purpose of this study was to investigate the relationship between hypercoiled cord and reversible DV-RAV in FGR.

METHODS

This was a retrospective study of 499 FGR cases, including 14 with DV-RAV. Transabdominal amnioinfusion (AI) was performed when oligohydramnios was severe (maximum vertical pocket <2 cm) and/or variable deceleration was detected. DV-RAV that disappeared quickly was defined as 'temporary DV-RAV'. DV-RAV that continued until delivery or fetal death (FD) was defined as 'persistent DV-RAV'. A hypercoiled cord was defined as one with an umbilical coiling index >0.6 antenatally or >0.3 postnatally. Clinical characteristics and clinical courses of the two types of DV-RAV were compared.

RESULTS

DV-RAV disappeared after AI in all five cases in which temporary DV-RAV was identified. The incidence of a hypercoiled cord was significantly higher among temporary DV-RAV cases (100%) than among persistent DV-RAV cases (14.3%; P = 0.015). The time from detection of DV-RAV to delivery or FD was significantly longer among temporary DV-RAV cases (4.5 weeks) than among persistent DV-RAV cases (0.7 weeks; P = 0.027).

CONCLUSION

Temporary DV-RAV is suspected to be related to the combination of a hypercoiled cord and oligohydramnios. DV-RAV may not be always be a terminal finding in FGR with a hypercoiled cord.

Fetal Vascular Malperfusion

CONTEXT

- Fetal vascular malperfusion, also known as fetal thrombotic vasculopathy, remains an underrecognized pathologic finding and should be noted during placental evaluation.

OBJECTIVE

- To review histologic findings, gain familiarity with the updated terminology, and to recognize important clinical associations with this entity.

DATA SOURCES

- University of Michigan cases, PubMed search, multiple review articles including recent placental workshop group consensus statement, and selected book chapters.

CONCLUSIONS

- Multiple histologic patterns of fetal vascular malperfusion have been described including thrombosis, avascular villi, villous stromal-vascular karyorrhexis, intramural fibrin thrombi, and stem villous vascular obliteration. Various underlying etiologies can be involved in fetal vascular malperfusion. Cord lesions including abnormal insertion, length, and coiling are important causes. Maternal vascular malperfusion such as preeclampsia, hypercoagulable states, lupus anticoagulant, and sometimes diabetes have been associated with this condition. Fetal cardiac dysfunction/malformations and severe fetal inflammatory response in the setting of ascending intrauterine infection have also been attributed to this important finding. Fetal vascular malperfusion has been implicated in several significant and sometimes devastating clinical associations; these include intrauterine growth restriction, poor perinatal outcome, fetal demise, and neurodevelopmental sequelae. A diagnostic challenge may be encountered in cases with prior intrauterine fetal death, since degenerative changes post demise result in a similar histomorphologic picture. The diffuse versus the focal nature of the lesions may help in the distinction.

Perinatal outcomes of abnormal umbilical coiling according to a modified umbilical coiling index

AIM

The aim of this study was to determine the relation between perinatal outcomes and umbilical cord coiling as evaluated by a modified umbilical coiling index.

METHODS

In this retrospective study, 200 consecutive umbilical cords were examined. An umbilical venous and arterial coiling index was calculated by dividing the total number of umbilical venous and arterial coils by the length of cord individually. Umbilical cords with umbilical venous coiling indices in the lowest decile, the highest decile, and the remaining deciles were defined as hypocoiled, hypercoiled, and normocoiled, respectively. The perinatal outcomes of the subjects with hypocoiled and hypercoiled umbilical cords were compared with those with normocoiled umbilical cords.

RESULTS

In 69.5% of subjects, a difference in the degree of coiling was detected between the umbilical veins and arteries. While all umbilical venous twisting demonstrated the same direction, the direction of the arterial twisting reversed at a certain point along the umbilical cord in 19.0% of the subjects. The arteriovenous coiling difference was small in the hypercoiled group and large in the hypocoiled group. A hypocoiled umbilical cord evaluated by umbilical venous coiling index was found to be associated with prolonged deceleration (odds ratio [OR], 4.18; 95% confidence interval [CI], 1.54-11.38), operative delivery (OR, 2.67; 95%CI, 1.01-7.09), and nuchal cord entanglement (OR, 3.21; 95%CI, 1.23-8.33).

CONCLUSION

Umbilical coiling abnormalities were investigated using a novel umbilical venous coiling index. A hypocoiled umbilical cord evaluated by umbilical venous coiling index was found to be associated with fetal heart rate abnormalities, operative delivery, and nuchal cord entanglement.

Sampling and Definitions of Placental Lesions: Amsterdam Placental Workshop Group Consensus Statement

CONTEXT

-The value of placental examination in investigations of adverse pregnancy outcomes may be compromised by sampling and definition differences between laboratories.

OBJECTIVE

-To establish an agreed-upon protocol for sampling the placenta, and for diagnostic criteria for placental lesions. Recommendations would cover reporting placentas in tertiary centers as well as in community hospitals and district general hospitals, and are also relevant to the scientific research community.

DATA SOURCES

-Areas of controversy or uncertainty were explored prior to a 1-day meeting where placental and perinatal pathologists, and maternal-fetal medicine specialists discussed available evidence and subsequently reached consensus where possible.

CONCLUSIONS

-The group agreed on sets of uniform sampling criteria, placental gross descriptors, pathologic terminologies, and diagnostic criteria. The terminology and microscopic descriptions for maternal vascular malperfusion, fetal vascular malperfusion, delayed villous maturation, patterns of ascending intrauterine infection, and villitis of unknown etiology were agreed upon. Topics requiring further discussion were highlighted. Ongoing developments in our understanding of the pathology of the placenta, scientific bases of the maternofetoplacental triad, and evolution of the clinical significance of defined lesions may necessitate further refinements of these consensus guidelines. The proposed structure will assist in international comparability of clinicopathologic and scientific studies and assist in refining the significance of lesions associated with adverse pregnancy and later health outcomes.

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.

Umbilical cord and preeclampsia

INTRODUCTION

Preeclampsia is associated with abnormalities in the umbilical cord in several ways: morphological, biochemical and functional. Alteration in blood vessels of the placenta, decidua and circulatory system of the fetus might be related to factors that cause preeclampsia and may be associated with alterations of the umbilical cord.

OBJECTIVES

This study aimed to analyze the relationship between each type of umbilical cord abnormality and the different subtypes of hypertensive gestational disorders.

METHODS

We conducted a prospective study on consecutive autopsies and its placentas, looking for abnormalities in the umbilical cord's features and their clinical associations.

RESULTS

Umbilical cord abnormalities including length, diameter, insertion, entanglements, knots and coils were associated with maternal gestational hypertension.

CONCLUSION

In women with gestational hypertension, umbilical cord abnormalities are associated with fetal and neonatal consequences.

Comprehensive imaging review of abnormalities of the umbilical cord

A complete fetal ultrasonographic (US) study includes assessment of the umbilical cord for possible abnormalities. Knowledge of the normal appearance of the umbilical cord is necessary for the radiologist to correctly diagnose pathologic conditions. Umbilical cord abnormalities can be related to cord coiling, length, and thickness; the placental insertion site; in utero distortion; vascular abnormalities; and primary tumors or masses. These conditions may be associated with other fetal anomalies and aneuploidies, and their discovery should prompt a thorough fetal US examination. Further workup and planning for a safe fetal delivery may include fetal echocardiography and karyotype analysis. Doppler US is a critical tool for assessment and diagnosis of vascular cord abnormalities. US also can be used for follow-up serial imaging evaluation of conditions that could result in fetal demise. Recent studies suggest that three- or four-dimensional Doppler US of the fetal umbilical cord and abdominal vasculature allows more accurate diagnosis of vascular abnormalities. Doppler US also is invaluable in assessment of fetal growth restriction since hemodynamic changes in the placenta or fetus would appear as a spectral pattern of increased resistance to forward flow in the fetal umbilical artery. Early detection of umbilical cord abnormalities and close follow-up can reduce the risk of morbidity and mortality and assist in decision making.

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.

Clinical associations to abnormal umbilical cord length in Latin American newborns

INTRODUCTION

Umbilical cord is vital to fetal development and its alterations are related to fetal and neonatal deaths and to late neurological complications. Abnormal cord length has been recognized as the most important cord feature leading to unfavorable outcomes. We aimed to examine the relationship between fetal abnormalities and the length of umbilical cord using the ECLAMC (Estudio Colaborativo Latinoamericano de Malformaciones Congénitas/Latin American Collaborative Study on Congenital Malformations) database.

METHODS

Using ECLAMC case-control registries, we conducted an observational study on the relationship between umbilical cord length and clinical variables such as chromosomal abnormalities and neonatal malformations.

RESULTS

Birth registries totaled 61820; of them 3411 had complete cord data. Abnormal length was found in 427, with 174 short (5.10%) cords and 253 long (7.41%) cords. No relation was found between abnormal cord length and gender, parity or parents' age. More abnormal length cords were found than reported in other series; unexpectedly, more long cords were observed in twin gestations. It was observed that among short cords (174), 105 were from newborns with some type of malformation and 69 with no malformation (OR = 2.92, CI (95%) 2.15-3.98, p = 0.0001); of the 253 long cords, 168 had malformation and only 85 did not (OR = 3.80, CI (95%) 2.91-4.96, p = 0.0001).

CONCLUSIONS

Abnormal cord length is associated with fetal malformation. Further studies are needed to determine the clinical applicability of using this parameter in counseling during prenatal visits.

Umbilical Cord Coiling and Zygosity: Is there a Link?

INTRODUCTION

The aim of this study was to analyze abnormalities of umbilical coiling index (UCI) in twin gestation to test whether the coiling is genetically influenced by zygosity.

METHODS

Data retrieved comprised gestational age (GA), chorionicity, fetal gender, and UCI.

RESULTS

The mean UCI of hypercoiled cords in monochorionic placentas was 0.55 coils/cm and 0.49 coils/cm in dichorionic placentas with discordant fetal gender (P = 0.2629).

DISCUSSION

In conclusion, no significant statistical difference between UCI in monochorionic and dichorionic twin placentas with discordant fetal gender was identified, suggesting that zygosity does not play a role in umbilical coiling induction.

Umbilical cord coiling: clinical outcomes in an unselected population and systematic review

This study was conducted to determine the frequency of pre-defined clinical outcomes in relation to umbilical cord coiling indices >90th percentile and <10th percentile in an unselected population of >1,000 women with a singleton pregnancy resulting in livebirth delivering at or near term and to report these findings in the context of a systematic review. Placentas of consecutive deliveries from an unselected low-risk population with >15 cm attached umbilical cords were included in the study. Clinical outcomes included interventional delivery, birthweight <10th percentile, Apgar score <7 at 1 min, neonatal acidosis (pH<7.2) and admission to neonatal special care. Standard MOOSE (Meta-analysis of Observational Studies in Epidemiology) guidelines were observed for the systematic review. Umbilical coiling index was determined for 1,082 placentas. Mean maternal age was 30.7 years (standard deviation [SD] =5.7) and 519 women (48 %) were primiparous. Mean cord length was 43 cm (SD=13) and mean cord coiling index 0.20 (SD=0.09). A total of 866 cords were normally coiled, and 108 cases were hypercoiled (>90th centile) and 108 cases were undercoiled (<10th percentile). There were no differences between cases of overcoiled, normally coiled or undercoiled cords for any clinical outcome studied. The systematic review yielded a small number of clinical studies which were too statistically and clinically heterogenous to permit meta-analysis. There is insufficient evidence either from this unselected cohort study or from a systematic review to support the previous suggestion that cord coiling index >90th centile or <10th centile is associated with adverse clinical outcome in an unselected population. Previous studies that draw a link between abnormal cord coiling and clinical outcome are generally too small and/or selective to allow meaningful conclusions or applicability to low-risk populations.

Evaluation of antenatal umbilical coiling index at 16-21 weeks of gestation as a predictor of trisomy 21 and other chromosomal defects

OBJECTIVES

To determine whether there is an association between sonographically assessed hyper- or hypocoiling of the umbilical cord and the presence of trisomy 21, to provide reference values for the antenatal umbilical coiling index (aUCI) at a gestational age of 16-21 weeks and to determine whether these measurements are reliable and reproducible.

METHODS

This was a prospective study of 737 pregnancies in which the aUCI was measured between 16 and 21 weeks of gestation by ultrasound at the time of amniocentesis. The aUCI was calculated as the reciprocal value of the mean length of one complete coil in centimeters. We created reference curves and studied the relationship with trisomy 21 and other chromosomal defects. In 30 pregnancies we studied the intra- and interobserver variation in measurements using Bland-Altman plots with associated 95% limits of agreement and intraclass correlation coefficients.

RESULTS

aUCI was found to be non-linearly related to gestational age at 16-21 weeks and reference curves were created for the mean aUCI and the 2.3(rd) , 10(th) , 90(th) and 97.7(th) percentiles. There was no significant difference in aUCI values between the reference group (n = 714) and cases with trisomy 21 (n = 16) or other aneuploidies (n = 7) (one-way ANOVA, P = 0.716). There was good intra- and interobserver agreement in aUCI measurements.

CONCLUSIONS

The aUCI can be measured reliably and varies according to gestational age at 16-21 weeks. The aUCI was not significantly associated with trisomy 21 or other chromosomal defects.

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.

Isolated abdominal wall defect with complete liver herniation without a covering or remnant membrane: an ominous sign: case report and review of literature

Complete liver herniation in abdominal wall defects without a membrane is rare and its prognosis is not well documented. We present a case diagnosed at 12 weeks of gestation. At 27 weeks, a C-section was performed for fetal distress. The infant proved impossible to ventilate and died. In literature, 16 similar cases are described of whom 14 died in the neonatal period and two in infancy. This suggests that herniation of the complete liver in isolated abdominal wall defects without a remnant membrane is lethal and counselling should be provided accordingly.

Overestimation of umbilical cord coiling index with segmental versus total length assessment

The umbilical cord is the only communication between the fetus and the placenta and, not surprisingly, lesions or conditions affecting it may have detrimental effects in both. One important feature of the umbilical cord is its coiling index (UCI), with hypo- and hypercoiling being associated with fetal thrombotic vasculopathy, intolerance of labor, intrauterine growth restriction, cord stricture, thrombosis of cord and chorionic blood vessels, and fetal demise. It is essential that every placenta report include the UCI. The UCI could also be assessed prenatally, but there is currently no way of accurately assessing the entire length of the umbilical cord. The aim of this study was to compare UCI measured in a segment of cord 10 cm long (UCI-10) and over its total length (UCI-T). One hundred fifty consecutive placenta reports in which both measurements were recorded were retrieved from the files and analyzed. Gestational age ranged from 16 to 42 weeks, with a mean of 33.67 ± 5.96 weeks and a median of 36 weeks. Mean UCI-10 was 0.4360 ± 0.2625 coils/cm and mean UCI-T was 0.3530 ± 0.2022 coils/cm; the difference between these measurements was highly statistically significant (P < 0.0001). Counting the number of umbilical cord coils in 10 cm led to an overestimation of the UCI-T by 23.5%; it can be concluded, therefore, that the latter should be used.

The relation between umbilical cord characteristics and the outcome of external cephalic version

BACKGROUND

Umbilical cords of fetuses in breech presentation differ in length and coiling from their cephalic counterparts and it might be hypothesised that these cord characteristics may in turn affect ECV outcome.

AIM

To investigate the relation between umbilical cord characteristics and the outcome of external cephalic version (ECV).

STUDY DESIGN

Prospective cohort study.

SUBJECTS

Women (>35 weeks gestation) with a singleton fetus in breech presentation, suitable for external cephalic version. Demographic, lifestyle and obstetrical parameters were assessed at intake. ECV success was based on cephalic presentation on ultrasound post-ECV. Umbilical cord length (UCL) and umbilical coiling index (UCI) were measured after birth.

OUTCOME MEASURE

The relation between umbilical cord characteristics (cord length and coiling) and the success of external cephalic version.

RESULTS

ECV success rate was overall 79/146 (54%), for multiparas 37/46(80%) and for nulliparas 42/100 (42%). Multiple logistic regression showed that UCL (OR: 1.04, CI: 1.01-1.07), nulliparity (OR: 0.20, CI: 0.08-0.51), frank breech (OR: 0.37, 95% CI: 0.15-0.90), body mass index (OR: 0.85, CI: 0.76-0.95), placenta anterior (OR: 0.27, CI: 0.12-0.63) and birth weight (OR: 1.002, CI: 1.001-1.003) were all independently related to ECV success.

CONCLUSIONS

Umbilical cord length is independently related to the outcome of ECV, whereas umbilical coiling index is not.

Relationship between placental morphology and histological findings in an unselected population near term

Whilst individual histological features are well described, there are no universally agreed criteria as to what constitutes a clinically significant histological lesion of the placenta in an uncomplicated pregnancy, nor has the presence of such histological findings been systematically related to quantitative morphological characteristics of the placenta (such as placental shape, cord insertion and cord coiling). This study aims to explore this relationship and further to describe the incidence of predefined categories of histological lesions of the placenta in an unselected obstetric population recruited prior to delivery. The study is based upon the placental examination of 1,156 women with singleton pregnancies recruited prospectively in a single unit. Placentas were analysed where deliveries occurred between 34-43 weeks. The incidence of normal histological findings and specific histological categories, such as ascending genital tract infection, chronic placental underperfusion, intervillous thrombus and villitis of unknown aetiology, were noted. The relationship between placental morphological indices: coiling index, cord centrality index (distance of cord insertion on the chorionic plate from the centre) and eccentricity (shape of the placenta) and histological lesions was investigated. There were no significant differences between cord centrality and eccentricity between placentas with and without histological lesions except an association between hypercoiling of the umbilical cord and intervillous thrombosis and villitis of unknown aetiology (p = 0.024 and p = 0.009, respectively). The macroscopic morphological features of the placenta cannot predict the presence or absence of the histological placental lesions, nor are these lesions in general associated with differences in cord centrality, placental eccentricity or cord coiling.

Placental pathology is associated with illness severity in preterm infants in the first twenty-four hours after birth

BACKGROUND

Placental pathology is associated with long-term neurological morbidity. Little is known about the association of placental pathology and illness severity directly after birth in preterm infants.

OBJECTIVE

To determine the association between placental pathology and illness severity in preterm infants during the first 24 h after birth.

STUDY DESIGN

Placentas of 40 preterm infants, born after singleton pregnancies (gestational age 25.4-31.7 weeks, birth weight 560-2250 g) were assessed for histopathology. Illness severity was measured using the Score of Neonatal Acute Physiology Perinatal Extension (SNAPPE). A high SNAPPE reflects high illness severity.

RESULTS

Examination of the 40 placentas revealed: pathology consistent with maternal vascular underperfusion (MVU) (n=24), ascending intrauterine infection (AIUI) (n=17), villitis of unknown aetiology (VUE) (n=6), foetal thrombotic vasculopathy (FTV) (n=6), elevated nucleated red blood cells (NRBCs) (n=6), and chronic deciduitis (n=10). SNAPPE ranged from 1 to 53 (median 10). Infants with elevated NRBCs had a higher SNAPPE than infants without elevated NRBCs (median 30 vs. 10, p=0.014). The same was found for the presence of FTV (median 30 vs. 10, p=0.019). No relation existed between SNAPPE and the other placental pathologies.

CONCLUSIONS

Elevated NRBCs and FTV were associated with higher illness severity during the first 24 h after birth in preterm infants. Ascending intrauterine infection was not associated with high illness severity.

Evidence-based pathology: umbilical cord coiling

The generation of a pathology test result must be based on criteria that are proven to be acceptably reproducible and clinically relevant to be evidence-based. This review de-constructs the umbilical cord coiling index to illustrate how it can stray from being evidence-based. Publications related to umbilical cord coiling were retrieved and analysed with regard to how the umbilical coiling index was calculated, abnormal coiling was defined and reference ranges were constructed. Errors and other influences that can occur with the measurement of the length of the umbilical cord or of the number of coils can compromise the generation of the coiling index. Definitions of abnormal coiling are not consistent in the literature. Reference ranges defining hypocoiling or hypercoiling have not taken those potential errors or the possible effect of gestational age into account. Even the way numerical test results in anatomical pathology are generated, as illustrated by the umbilical coiling index, warrants a critical analysis into its evidence base to ensure that they are reproducible or free from errors.

First trimester umbilical cord and vitelline duct measurements using virtual reality

BACKGROUND

the umbilical cord and vitelline duct are of vital importance to the fetus, but they are rarely the subject of first trimester two-dimensional (2D) ultrasound evaluation due to the complexity of their shape and morphology. Virtual reality (VR) allows efficient visualisation and measurement of complex structures like the umbilical cord and vitelline duct.

AIM

to measure normal first trimester human growth of the umbilical cord length (UCL) and vitelline duct length (VDL) using a VR system; and to correlate both measurements with the gestational age (GA) and crown-rump length (CRL) and the VDL with the yolk sac volume (YSV).

STUDY DESIGN

prospective cohort study. Serial three-dimensional (3D) ultrasound measurements were performed from six to 14weeks GA, resulting in 125 3D volumes. These volumes were analysed using an I-Space VR system.

SUBJECTS

Thirty-two healthy pregnant women with an ongoing, normal pregnancy.

OUTCOME MEASURES

the UCL, VDL, YSV and other related structures were measured.

RESULTS

The UCL, measurable in 55% of cases, was positively correlated to advancing GA and CRL (p<0.001). The VDL could be measured in 42% of cases and showed a positive relationship with GA and CRL (p<0.001). There was a significant (p<0.001) relationship between YSV and VDL.

CONCLUSIONS

the present study, facilitated by a VR system, is the first to provide an in-vivo longitudinal description of normal first trimester growth of the human umbilical cord and vitelline duct. Further studies will reveal whether these parameters can be used in detection of abnormal fetal development.

Hypercoiling of the umbilical cord and placental maturation defect: associated pathology?

Our objective was to determine whether there is an association between hypercoiling of the umbilical cord and placental maturation defect. From a database comprising 1147 cases, containing data on all placentas examined at our institution during the study period, we selected all cases with a gestational age of at least 37 weeks that exhibited hypercoiling of the umbilical cord (coiling density above the 90th percentile, n = 42); we also examined 2 matched controls for each case, one with hypocoiling and one with normocoiling. The mean number of syncytiocapillary membranes (SCM) per terminal villus was calculated. Presence of a placental maturation defect was defined as the mean number of SCM below the 10th percentile. Correlations were assessed using Spearman's rho. Relations between dichotomous variables were tested using logistic regression. Mean number of SCM per terminal villus (+/-standard deviation) was 1.25 +/- 0.65. Difference in mean between hypo- and hypercoiled cords was 0.37 (95% confidence interval [CI], 0.07 to 0.67). The correlation coefficient between mean number of SCM and umbilical coiling index (UCI, coils/cm) was -0.28 (P = 0.002). The odds ratio (OR) for placental maturation defect in presence of hypercoiling was 2.61 (95% CI, 0.75 to 9.12). The OR for fetal death was 132 (95% CI, 13.2 to 1315) in the presence of a placental maturation defect and 5.49 (95% CI, 1.02 to 29.6) in the presence of hypercoiling. The OR for indication of fetal hypoxia/ischemia was 12.3 (95% CI, 3.0 to 50.3) in the presence of a placental maturation defect and 3.2 (95% CI, 0.95 to 10.9) in the presence of hypercoiling. We found a trend toward placental maturation defect in the presence of hypercoiling and an inverse relationship between the mean number of SCM in the terminal villi and the UCI. We confirmed associations between fetal death and both a maturation defect and hypercoiling and found an association between histological indication of fetal hypoxia/ischemia and a placental maturation defect.

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.