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

Twisting the theory on the origin of human umbilical cord coiling featuring monozygotic twins

The human umbilical cord (hUC) is the lifeline that connects the fetus to the mother. Hypercoiling of the hUC is associated with pre- and perinatal morbidity and mortality. We investigated the origin of hUC hypercoiling using state-of-the-art imaging and omics approaches. Macroscopic inspection of the hUC revealed the helices to originate from the arteries rather than other components of the hUC. Digital reconstruction of the hUC arteries showed the dynamic alignment of two layers of muscle fibers in the tunica media aligning in opposing directions. We observed that genetically identical twins can be discordant for hUC coiling, excluding genetic, many environmental, and parental origins of hUC coiling. Comparing the transcriptomic and DNA methylation profile of the hUC arteries of four twin pairs with discordant cord coiling, we detected 28 differentially expressed genes, but no differentially methylated CpGs. These genes play a role in vascular development, cell-cell interaction, and axis formation and may account for the increased number of hUC helices. When combined, our results provide a novel framework to understand the origin of hUC helices in fetal development.

Clinical value of placental examination for paediatricians

The placenta contains valuable clinical information that is linked to fetal development, neonatal morbidity and mortality, and future health outcomes. Both gross inspection and histopathological examination of the placenta may identify intrinsic or secondary placental lesions, which can contribute directly to adverse neonatal outcomes or indicate the presence of an unfavourable intrauterine environment. Placental examination therefore forms an essential component of the care of high-risk neonates and at perinatal post-mortem examination. In this article, we describe the clinical value of placental examination for paediatricians and perinatal clinicians. We discuss common pathological findings on general inspection of the placenta with photographic examples and provide an overview of the placental pathological examination, including how to interpret key findings. We also address the medico-legal and financial implications of placental examinations and describe current and future clinical considerations for clinicians in regard to placental examination.

Re-evaluation of umbilical cord coiling index in adverse pregnancy outcome - Does it have role in obstetric management?

Introduction

The placenta with the umbilical cord is a vital link between the mother and fetus. Umbilical cord supplies water, nutrients and oxygen from the mother to the fetus. The most unique character of the umbilical cord is its coiling, where the contents of the cord course in a coiled helical fashion. The umbilical coiling index(UCI) can be measured antenatally using ultrasonography. In the present study we have attempted to assess the UCI antenatally by ultrasound screening and correlate abnormal antenatal UCI with the adverse maternal and neonatal outcome of pregnancy.

Aims

To study umbilical coiling index ultrasonographically and to correlate it with pregnancy outcome.

Methodology

150 antenatal cases in the second trimester of pregnancy between 22 and 28weeks of gestation attending the outpatient department were included for the study in a continuous manner and subjected to antenatal UCI measurement. The cases were followed up till delivery and various factors were noted.

Results

We confirmed that maternal medical comorbidities ( gestational hypertension and anemia) have a significant correlation with abnormal umbilical cord coiling index, either hyper-coiling or hypo-coiling or both.Some studies have shown a particular adverse effect being manifested in both hypo and hypercoiling. In the present study significant correlation of abnormal coiling has been found with only anaemia and hypertension in pregnancy. The question, therefore, arises:"Does abnormal UCI have any significant role in prediction of adverse outcome in pregnancy or is it just a random association?" This study does not reflect any significant role of abnormal UCI in the prediction of adverse perinatal outcome. Hence efforts to monitor UCI in the antenatal period may not have any justification in the present scenario. The latest edition of William's Obstetrics also makes a similar comment. A population based larger study to generate cut offs for hypo and hyper coiling and finding any association between abnormal coiling and perinatal outcome may throw more light on the utility of UCI as a predictor of adverse outcome in pregnancy.

Macroscopic lesions of maternal and fetal vascular malperfusion in stillborn placentas: Diagnosis in the absence of microscopic histopathological examination

INTRODUCTION

Lesions of maternal vascular malperfusion (MVM) and fetal vascular malperfusion (FVM) are common in placentas associated with both stillbirth and live birth. The objective of this study was to identify lesions present more commonly in stillborn placentas and those most indicative of MVM and FVM without microscopic pathologic evaluation.

METHODS

Data were derived from the Stillbirth Collaborative Research Network. Lesions were identified according to standard protocols published previously and categorized as either MVM or FVM according to the Amsterdam Placental Workshop Group Consensus Statement and macroscopic "umbilical cord at risk" findings. Multivariate logistic regression was used to determine the odds of stillbirth with macroscopic findings of MVM or FVM.

RESULTS

595 stillbirths and 1,305 live births were analyzed. FVM lesions (85.2%) were marginally more common (though not statistically different) in stillbirths compared to MVM lesions (81.3%). Macroscopic findings of both MVM and FVM were more common in stillbirths versus livebirths (p < 0.001). Odds ratios of macroscopic MVM and FVM lesions for stillbirth, adjusted for gestational age at delivery, maternal race (minority), ethnicity (Hispanic), age, and history of hypertension or diabetes, were 1.48 (95% CI 1.30-1.69) and 1.34 (95% CI 1.18-1.53), respectively.

DISCUSSION

Macroscopic features of MVM and FVM are associated with higher odds of stillbirth versus live birth even when controlled for gestational age and maternal factors, which may be a useful clue in determining the pathophysiology of these events. This information is also useful for pathologists when microscopic examination is not available.

Analysis of factors associated with the umbilical cord pitch value by ultrasound measurement in late pregnancy

BACKGROUND

This study aimed to investigate the factors associated with the antenatal umbilical cord pitch value by ultrasound measurement in late pregnancy. We investigated the factors associated with the umbilical cord pitch value under prenatal ultrasound measurement.

METHODS

This study included 528 pregnant women who underwent routine antenatal ultrasound examinations in Ningbo Women and Children's Hospital from December 2020 to August 2021. Their umbilical cord pitch values and diameter, Wharton's jelly thickness, amniotic fluid indexes, umbilical artery blood flow parameters, and other relevant data, such as ages and gestational ages, were measured. Information about delivery methods, placenta, umbilical cord, and neonatal weight were recorded during follow-up. Statistical analysis was performed on the above data, and the factors associated with the pitch values were analyzed by linear regression.

RESULTS

This study revealed that cord torsion (p < 0.001, 95% confidence interval [CI]=-34.81 to -19.01), cord entanglement (p < 0.001, 95% CI = 10.71 to 20.11), thickening of Wharton's jelly (p = 0.001, 95% CI = 5.39 to 20.24), and cord edema (p = 0.015, 95%CI = 2.09 to 19.44), gestational age (p = 0.024, 95%CI = 0.14 to 1.89), age of pregnant woman (p = 0.009, 95%CI= -1.15 to -0.16), and neonatal weight (p = 0.011, 95%CI = 0.002 to 0.012) were significantly correlated with the pitch values.

CONCLUSION

The umbilical cord pitch value significantly correlated with cord entanglement, cord torsion, cord edema, Wharton's jelly thickening, gestational age, age of the pregnant woman, and neonatal weight. Notably, the pitch value by prenatal ultrasound measurement is predictive of cord morphological abnormalities such as cord entanglement, cord torsion, cord edema, and Wharton's jelly thickening.

Analysis of placental pathology after COVID-19 by timing and severity of infection

BACKGROUND

COVID-19 during pregnancy can have serious effects on pregnancy outcomes. The placenta acts as an infection barrier to the fetus and may mediate adverse outcomes. Increased frequency of maternal vascular malperfusion has been detected in the placentas of patients with COVID-19 compared with controls, but little is known about how the timing and severity of infection affect placental pathology.

OBJECTIVE

This study aimed to examine the effects of SARS-CoV-2 infection on placental pathology, specifically whether the timing and severity of COVID-19 affect pathologic findings and associations with perinatal outcomes.

STUDY DESIGN

This was a descriptive retrospective cohort study of pregnant people diagnosed with COVID-19 who delivered between April 2020 and September 2021 at 3 university hospitals. Demographic, placental, delivery, and neonatal outcomes were collected through medical record review. The timing of SARS-CoV-2 infection was noted, and the severity of COVID-19 was categorized on the basis of the National Institutes of Health guidelines. The placentas of all patients with positive nasopharyngeal reverse transcription-polymerase chain reaction COVID-19 testing were sent for gross and microscopic histopathologic examinations at the time of delivery. Nonblinded pathologists categorized histopathologic lesions according to the Amsterdam criteria. Univariate linear regression and chi-square analyses were used to assess how the timing and severity of SARS-CoV-2 infection affected placental pathologic findings.

RESULTS

This study included 131 pregnant patients and 138 placentas, with most patients delivered at the University of California, Los Angeles (n=65), followed by the University of California, San Francisco (n=38) and Zuckerberg San Francisco General Hospital (n=28). Most patients were diagnosed with COVID-19 in the third trimester of pregnancy (69%), and most infections were mild (60%). There was no specific placental pathologic feature based on the timing or severity of COVID-19. There was a higher frequency of placental features associated with response to infection in the placentas from infections before 20 weeks of gestation than that from infections after 20 weeks of gestation (P=.001). There was no difference in maternal vascular malperfusion by the timing of infection; however, features of severe maternal vascular malperfusion were only found in the placentas of patients with SARS-CoV-2 infection in the second and third trimesters of pregnancy, not in the placentas of patients with COVID-19 in the first trimester of pregnancy.

CONCLUSION

Placentas from patients with COVID-19 showed no specific pathologic feature, regardless of the timing or severity of the disease. There was a higher proportion of placentas from patients with COVID-19-positive tests in earlier gestations with evidence of placental infection-associated features. Future studies should focus on understanding how these placental features in SARS-CoV-2 infections go on to affect pregnancy outcomes.

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.

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.

How to Reach the Best Ultrasound Performance in the Delivery Room

Ultrasonography is an instrument that is present in the maternal-fetal assessment throughout pregnancy and with widely documented benefits, but its use in intrapartum is becoming increasingly relevant. From the assessment of labor progression to the assessment of placental disorders, ultrasound can be used to correlate with physiological findings and physical examination, as its benefit in the delivery room cannot yet be proven. There are still few professionals with adequate training for its use in the delivery room and for the correct interpretation of data. Thus, this article aims to present a review of the entire applicability of ultrasound in the delivery room, considering the main stages of labor. There is still limited research in evidence-based medicine of its various possible uses in intrapartum, but it is expected that further studies can bring improvements in the quality of maternal and neonatal health during labor.

Considering the Effects and Maternofoetal Implications of Vascular Disorders and the Umbilical Cord

The umbilical cord is a critical anatomical structure connecting the placenta with the foetus, fulfilling multiple functions during pregnancy and hence influencing foetal development, programming and survival. Histologically, the umbilical cord is composed of three blood vessels: two arteries and one vein, integrated in a mucous connective tissue (Wharton's jelly) upholstered by a layer of amniotic coating. Vascular alterations in the umbilical cord or damage in this tissue because of other vascular disorders during pregnancy are worryingly related with detrimental maternofoetal consequences. In the present work, we will describe the main vascular alterations presented in the umbilical cord, both in the arteries (Single umbilical artery, hypoplastic umbilical artery or aneurysms in umbilical arteries) and the vein (Vascular thrombosis, aneurysms or varicose veins in the umbilical vein), together with other possible complications (Velamentous insertion, vasa praevia, hypercoiled or hypocoiled cord, angiomyxoma and haematomas). Likewise, the effect of the main obstetric vascular disorders like hypertensive disorders of pregnancy (specially pre-eclampsia) and chronic venous disease on the umbilical cord will also be summarized herein.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Early versus delayed oxytocin infusion following amniotomy for induction of labor: a meta-analysis of randomized controlled trials

BACKGROUND

Oxytocin infusion prior to confirmation of delay in labor is discouraged by the World Health Organization. However, evidence from the Cochrane library seems to support early amniotomy and oxytocin to reduce the rates of cesarean sections (CS).

OBJECTIVES

To investigate differences in mode of delivery among parturient receiving early versus delayed oxytocin infusion following amniotomy as a mean for augmentation of labor.

SEARCH STRATEGY

We searched Medline, Scopus, EMBASE, Cochrane Central Register of Controlled Trials and Google Scholar databases from inception till February 2020. Selection criteria: Randomized controlled trials.

DATA COLLECTION AND ANALYSIS

Data were collected using a modified Cochrane data collection form for intervention reviews. Meta-analysis was performed using the meta function in RStudio.

MAIN RESULTS

Five studies were included that involved 1.232 parturient. The meta-analysis did not reveal significant differences in the mode of delivery among women that were randomized to receive immediate oxytocin infusion and those that received delayed oxytocin infusion (operative vaginal delivery OR 1.14, 95% CI 0.48, 2.69) and CS OR 0.81, 95% CI 0.53, 1.25)). The interval from amniotomy to delivery was significantly smaller in the immediate oxytocin infusion group; however, prediction intervals were not significant.

CONCLUSIONS

The results of our meta-analysis suggest that there is no difference in the mode of delivery and interval from amniotomy to delivery when oxytocin is delayed for at least one hour following amniotomy. Taking in mind this information as well as current recommendations drawn from the WHO physicians should consider withholding oxytocin infusion at least until protracted labor is confirmed.

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.

Fetal Vascular Malperfusion Due To Long and Hypercoiled Umbilical Cords Resulting in Recurrent Second Trimester Pregnancy Loss: A Case Series and Literature Review

BACKGROUND

Intrauterine fetal demise due to fetal vascular malperfusion in mid-gestation is a rare occurrence. Abnormally long and hypercoiled umbilical cords are associated with an increased risk of umbilical cord blood flow restriction, which in turn can result in adverse perinatal and maternal outcomes. The factors that regulate umbilical cord development, specifically umbilical cord length and coiling, are poorly understood.

METHODS

Maternal history, along with fetal and placental findings (post-mortem, pathological, and molecular), were reviewed for a series of 3 consecutive pregnancies that ended in second trimester intrauterine fetal demise.

RESULTS

All 3 umbilical cords were exceptionally long and hypercoiled, and all placentas showed evidence of high-grade fetal vascular malperfusion. At fetopsy, all 3 fetuses were developmentally normal for gestational age and lacked congenital anomalies. Maternal medical history and antenatal testing (including an extensive work-up for maternal hypercoagulability syndromes) were normal and/or noncontributory.

CONCLUSION

Although excessively long and hypercoiled cords are generally thought of as sporadic, nongenetic events, rare examples of recurrent intrauterine fetal demise secondary to such exist have been reported. This intrafamilial clustering of a rare event is suggestive that at least a subset of hypercoiled, long umbilical cords may have an underlying genetic etiology.

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.

Perinatal outcomes of cases with umbilical hypocoiled cord: a study at a single perinatal center

OBJECTIVES

To evaluate the perinatal outcomes of hypocoiled cord.

METHODS

This retrospective study was carried out in the Department of Obstetrics and Gynecology at Showa University Hospital between 2011 and 2017. Umbilical cord index (UCI) was calculated by dividing the total number of coils by the total length of umbilical cord. All umbilical cords were measured and calculated coiling index by obstetrician after delivery. Perinatal outcomes like non-reassuring fetal status (NRFS), emergency cesarean sections, and other perinatal complications were compared.

RESULTS

From January 2011 to December 2017, a total of 4047 fetuses were born at our hospital after 28 weeks' gestation. After excluding 100 fetuses of hypercoiled cord, a total of 3947 fetuses were included in this study, of which 71 fetuses were hypocoiled cord and 3876 fetuses were normal coiled cord. There were no association between maternal background and both UCI group. NRFS during labor was significantly associated with hypocoiled cord compared with normal cord (p = .02). Additionally, the rates of emergency cesarean section were raised in cases of hypocoiled cord (p = .02).

CONCLUSION

In this study, it was found that hypocoiled cord is related to NRFS and emergency cesarean section. In addition, hypocoiled cord was not associated with any maternal factors. However, in previous studies, no opinion has been reported on the timing of diagnosis of hypocoiled cord during pregnancy. It is difficult to evaluate hypocoiled cord correctly in third trimester. It is a task to find the hypocoiled cord correctly before birth.

Investigation of the outcome of pregnancies complicated by increased fetal movements and their relation to underlying causes - A prospective cohort study

INTRODUCTION

Retrospective studies have reported an association between a single episode of significantly increased fetal movements (IFMs) and stillbirth after 28 weeks' gestation. This prospective study aimed to report the outcome of pregnancies associated with maternal perception of IFMs and determine whether this symptom is associated with adverse pregnancy outcome, a pathological intrauterine environment or placental dysfunction.

MATERIAL AND METHODS

Women reporting IFMs after 28 weeks' gestation were recruited from St Mary's Hospital, Manchester and Liverpool Women's Hospital, UK, between 1 November 2017 and 1 May 2019. Demographic and clinical information were obtained and an ultrasound scan was performed to assess fetal biometry, liquor volume and umbilical artery Doppler. Maternal serum samples were collected for analysis of placentally derived biomarkers using ELISA. After delivery, maternal and fetal outcome data were collected and placentas and umbilical cord blood were obtained for analysis using immunohistochemistry and ELISA, respectively. Placental and serum samples were matched by gestation and maternal characteristics to participants with normal fetal activity.

RESULTS

Seventy-seven women presented with IFM, representing 0.45% of the maternity population; 64 women consented to participate in the study, of which 7 (10.9%) experienced adverse pregnancy outcome: birthweight <3rd centile, 2 (3.1%); pH ≤7.10, 1 (1.6%); neonatal intensive care unit admission, 4 (6.3%). Women had IFM for varying lengths of time before presenting: 17.2% had IFM for less than 1 hour and 29.7% reported IFM lasting longer than 24 hours. Four women (6.3%) had abnormalities of the fetal heart rate trace on assessment. Women with IFM had similar modes of birth to women giving birth in participating maternity units. There was no evidence of macroscopic placental or umbilical cord abnormalities, alterations in microscopic placental structure, placental endocrine dysfunction or intrauterine hypoxia or infection in women with IFM compared with controls.

CONCLUSIONS

This prospective study did not find evidence of an association between IFM and adverse pregnancy outcome. It also did not find evidence of underlying placental dysfunction, cord anomalies, intrauterine hypoxia or infection in pregnancies with IFM. Further work is required to determine the strength of association between IFM and adverse pregnancy outcome and its origins. At present, IFM cannot be used to identify fetuses at increased risk of adverse outcome.

Wharton's jelly area and its association with placental morphometry and pathology

INTRODUCTION

Wharton's jelly (WJ) is the mucoid connective tissue that surrounds the vessels in the human umbilical cord and provides protection from compression and torsion in response to fetal movement. WJ is known to be altered in the presence of pregnancy complications such as gestational diabetes mellitus and preeclampsia. The present study examined associations between the cross-sectional area of WJ measured by ultrasound and postpartum placental pathology and morphometry.

METHODS

The area of WJ was measured by ultrasound in 156 eligible participants between 23 and 37 weeks' gestation. Morphometric assessment of fixed cord cross sections was conducted, together with assessment of the cord and placenta for specific pathologies using standard criteria.

RESULTS

From 156 participants, 123 ultrasound images met the data quality requirements and pathology reporting was completed for 99 placentas. 17 of the participants (14%) delivered a small for gestational age neonate and 32 of the 99 placentas examined (32%) had significant placental pathology findings. Area of WJ was associated with low birth weight (p = 0.002) and was associated with specific placental pathology (p = 0.01). WJ area was positively associated with placental dimensions such as width, length and surface area.

DISCUSSION

Decreased WJ area is associated with clinically-significant placental pathology and WJ area scales proportionally with placental size. These findings suggest that WJ area correlates with functional capacity of the placenta and thus merits further evaluation alongside currently-available tests of placental function in clinical practice.

Evaluation of umbilical cord entanglement as a predictive factor of adverse pregnancy outcomes: A meta-analysis

The purpose of the present systematic review is to summarize current data concerning the impact of umbilical cord entanglement on adverse pregnancy outcomes. We used the Medline, Scopus, EMBASE, Cochrane Central Register of Controlled Trials CENTRAL and Google Scholar databases. We selected all observational (both prospective and retrospective) studies for inclusion. Meta-analysis of the risk ratios (RR) was performed with RevMan 5.3 software. Univariate meta-regression and leave-one-out meta-analysis was performed with Open Meta-Analyst statistical software. Trial sequential analysis was performed with the TSA software. Overall, twenty studies were included in the present study with 267,233 pregnant women (50.103 with cord entanglement and 217,130 controls). An increased risk of neonatal Apgar score <7 at the first minute of life was observed among cases with cord entanglement (RR = 1.75, 95% CI 1.46, 2.11). Fetal distress was significantly higher in the entanglement group (RR 1.50, 95% CI 1.33, 1.69). The incidence of fetal pH < 7.1 was also significantly higher in the entanglement group (RR 1.73, 95% CI 1.48, 2.03). Adequate power was observed in all investigated outcomes of our primary analysis after evaluating the results of the TSA analysis. Prediction intervals designated that future studies were likely to report increased risk of low Apgar score at the first minute of life, increased risk of fetal distress as well as of observing a fetal pH < 7.1. Concluding, the findings of this systematic review suggest that there is sufficient evidence to support the involvement of cord entanglement to adverse neonatal perinatal outcomes.

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.

Differences in perinatal outcomes according to forming period of single umbilical cord in singleton pregnancy

OBJECTIVES

The aim of this study was to establish the frequency and associations of single umbilical artery (SUA) diagnosed until the first vs second or third trimester.

METHODS

A retrospective cohort study was conducted on singleton pregnancies at a tertiary perinatal center. All women underwent both the first and second trimester scans in which the number of arteries in the umbilical cord was routinely documented. SUA was classified as aplastic type when the diagnosis was made in the first trimester and as occlusion type when diagnosed in the second or third trimester. Adverse perinatal outcome was calculated as occurrence of fetal death, birthweight centile < 10^th , or Apgar score at 5 minutes < 7.

RESULTS

A total of 8675 women underwent ultrasound examinations during the study period. Of the 32 SUA cases, 17 (0.2%) were of the aplastic type and 15 (0.2%) of the occlusion type. Congenital anomalies were more in aplastic than in occlusive SUA (58.8% vs 20%, .043). The occlusive SUA had higher postnatal coiling index (0.3 vs 0.2, .034) and diagnosis of hypercoiled cord (46.7% vs 5.9%, .013) than the aplastic type.

CONCLUSIONS

The different gestational age at diagnosis and coiling characteristics suggest two types of SUA, namely, aplastic and occlusion types, which are associated with differences in perinatal outcomes.