Extreme umbilical cord lengths, cord knot and entanglement: Risk factors and risk of adverse outcomes, a population-based study

Umbilical cord length and neurodevelopmental disorders, a national cohort study

INTRODUCTION

Adversities in fetal life are known risk factors for neurodevelopmental disorders (NDD). Despite the pivotal role of the umbilical cord, little is known about its associations to later NDD.

OBJECTIVE

To estimate the associations between umbilical cord length and NDD (Attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), intellectual disability (ID), cerebral palsy (CP), epilepsy, impaired vision or hearing), and whether associations differed by sex.

MATERIALS AND METHODS

A prospective population-based cohort study including all liveborn singletons in Norway from 1999, through 2013 and followed up through 2019. Data were retrieved from The Medical Birth Registry of Norway and linked with other national health and administrative registries. Exposures were extreme umbilical cord length (empirical percentile <5th or ≥ 95th percentiles). Main outcome measures were NDD (ADHD, ASD, ID, CP, epilepsy, impaired vision or hearing). Associations with umbilical cord length were assessed using logistic regression.

RESULTS

The cohort consisted of 858,397 births (51.3% boys). We identified 33,370 persons with ADHD (69.8% boys), 10,818 had ASD (76.0% boys), 5538 ID (61.4% boys), 2152 with CP (59.9% boys), 8233 epilepsy (55.0% boys), 900 impaired vision (boys 55.0%), and 11,441 impaired hearing (boys 52.8%). Cord length was positively associated with ADHD (OR 1.15; 95%CI 1.09-1.22), i.e., the risk increased with long cord and decreased with short cord, regardless of sex. A short cord was positively associated with ID (OR 2.42; 95%CI 2.17-2.69), impaired hearing (OR 1.41; 95%CI 1.29-1.54), and epilepsy (OR 1.31; 95%CI 1.18-1.46). CP was associated with both short and long cord (OR 1.31; 95% CI 1.07-1.61 and 1.34, 95%CI 1.13-1.60, respectively). There was no association between cord length and impaired vision.

CONCLUSIONS

This first population study finds that umbilical cord length is associated with NDD. The findings support the hypothesis that neurodevelopment and development of the umbilical cord share pathways.

Effect of gestational diabetes mellitus and its management on the histological and histomorphometric structure of umbilical cord: a comparative study

The umbilical cord lacks vasavasorum and is prone for hypoxic injuries. Gestational diabetes mellitus (GDM) causes structural changes with in umbilical cord blood vessels. Knowledge of which would be helpful for the gynecologist and obstetricians to assess the prognosis and prevent the complications. The present study was concentrated from December 2016 to December 2019 on 50 normal and 56 GDM umbilical cords. GDM group included 23 GDM mothers managed by diet (GDM-Diet) and 33 GDM mothers managed by drugs (GDM-Drug). Placentas along with the attached umbilical cords were collected and stored in 10% formaline. Tissue processing, slide preparation and stainings were done using standard protocols. A significant reduction was observed in the number of Hoboken nodules of umbilical arteries of GDM-Diet. Reduction of myofibroblasts with an increase in the empty spaces was observed in the Wharton's jelly of both GDM cases. Similarly, smooth muscle disintegration and migration of smooth muscles to intima was significantly higher in GDM umbilical arteries and veins than normal umbilical vessels. The total wall thickness and tunica media was significantly thicker in the umbilical arteries of GDM-Drug group only. The umbilical venous lumen was found significantly wider in GDM groups compared to normal. The elastin fibers were significantly found reduced in the tunics of umbilical arteries and veins in GDM. However, a significant difference in these parameters was not observed between the GDM-Diet and GDM-Drug groups except for total wall and tunica media thickness of umbilical arteries.

Adverse Perinatal Outcomes Associated with True Knot of the Umbilical Cord: A Multicenter Retrospective Study

This study aimed to estimate the prevalence of true knot of the umbilical cord (TKUC) and identify associated adverse maternal and neonatal outcomes.A multicenter retrospective cohort study was conducted, including all women with singleton pregnancies who delivered between 24 and 42 weeks of gestation from 2005 to 2021 at two large obstetrical centers. Gross pathological examinations of the placenta and umbilical cord were routinely performed immediately after delivery. Women with TKUC detected postpartum were compared with those without TKUC. Maternal and neonatal characteristics, along with adverse outcomes, were compared between the two groups.During the study period, 283,055 deliveries met inclusion and exclusion criteria. The incidence of TKUC was 1.3%, intrauterine fetal death (IUFD) rate was significantly higher in the TKUC group (1.8% vs. 0.3%), with 91% of these deaths occurring after 34 weeks of gestation, and 72% occurring after 37 weeks. Women with TKUC experienced higher rates of preterm premature rupture of membranes, premature rupture of membranes, induction of labor, meconium-stained amniotic fluid, vacuum-assisted vaginal delivery, and postpartum hemorrhage. The rate of intrapartum cesarean deliveries was similar between the groups. Neonatal outcomes revealed similar birth weights, but higher rates of small-for-gestational-age neonates, low Apgar scores, jaundice, hypoglycemia, and intracranial hemorrhage in the TKUC group. Multivariate analysis demonstrated that TKUC was independently associated with IUFD (adjusted odds ratios [aOR]: 6.07; 95% confidence intervals [CI]: 4.68-7.86, p < 0.01).TKUC is not uncommon and is associated with an increased risk of IUFD, particularly in the late third trimester, as well as adverse neonatal outcomes. Early diagnosis in the third trimester followed by delivery in the late preterm or early term period may reduce IUFD rates. · TKUC occurred in 1.3% of approximately 300,000 deliveries.. · It is associated with a sixfold higher risk of IUFD.. · Most IUFDs (91%) occurred > 34 weeks, with 72% occurring > 37.. · Third-trimester ultrasound and delivery at approximately 37 weeks may reduce IUFD..

The invisible killer: fetal vascular malperfusion in stillbirths without macroscopic cord abnormalities

Objective

The aim was to evaluate the association between fetal vascular malperfusion (FVM) and the umbilical cord characteristics in stillbirth. FVM is a category of placental lesions consistent with restriction/interruption of fetal blood flow, frequently associated with a "cord accident". In some stillbirths, gross umbilical cord abnormalities unravel at birth, helping to elucidate the cause of death; however, other cases do not show any structural alterations and therefore these cases do not have an obvious cause of death.

Methods

Retrospective histopathological evaluation of singleton antepartum stillbirths affected by of FVM. Clinical and histopathological findings were compared among cases with or without gross umbilical cord abnormalities.

Results

One hundred and three cases were evaluated. Forty-eight cases (48/103; 46.6%) of stillbirth with FVM showed gross umbilical cord abnormalities, whereas 55/103 cases (53.4%) did not show any gross anomalies. Clinical risk factors for stillbirth were equally distributed between cases. Notably, the main histological lesion observed in cases without gross umbilical cord abnormalities was fatal thrombosis of the fetal vessels along the cord-placental vascular tree. This finding implies that the absence of macroscopic cord anomalies is not a sufficient criterion to exclude reduction/interruption of fetal blood flow and cord accidents as a potential cause of stillbirth.

Conclusion

Knowing the cause of fetal death is paramount both for bereaved parents and clinicians, helping in stillbirth acceptance and future prevention strategies. Our findings show the occurrence of FVM in cases without macroscopic umbilical cord anomalies. Therefore, an in-depth placental histopathological examination is mandatory to unravel signs of fetal blood flow obstruction in cases in which umbilical cord looks grossly normal. This knowledge helps parents, and health care providers in the real identification of the pathogenesis of fetal death, as the first step for personalized future actions of stillbirth prevention.

Risk factors and outcomes associated with true knots of the umbilical cord: A retrospective study

OBJECTIVE

To investigate the pregnancy outcomes and independent risk factors associated with true knots of the umbilical cord (TKUC).

MATERIALS AND METHODS

This retrospective study included 8140 deliveries at Fujian Maternal and Child Health Hospital from 2017 to 2021. Mothers and newborns diagnosed with TKUC were included in the TKUC group, while the others were included in the control group. The data were obtained from the hospital's electronic medical record system. Multiple pregnancies were excluded.

RESULTS

The incidence of TKUC was 0.61 %. The TKUC group had significantly higher proportions of advanced maternal age, multiparae and mothers with more than two pregnancies (P < 0.05). The neonates in the TKUC group were more male, had longer lengths and umbilical cords, heavier placentas, and a higher incidence of umbilical cord entanglement (P < 0.05). In terms of pregnancy outcomes, the TKUC group exhibited higher rates of cesarean section and preterm birth (P < 0.001; P < 0.05). However, there were no significant differences in birthweight, Apgar scores, stillbirth rate, and neonatal malformation rate between the two groups (P > 0.05). The results of logistic regression indicated that multiparae (OR = 1.386, P = 0.001), male fetus (OR = 1.499, P < 0.001), excessive long umbilical cord (OR = 11.022, P < 0.001), and umbilical cord entanglement (OR = 1.284, P = 0.019) were risk factors for TKUC.

CONCLUSION

Male fetus, multiparae, umbilical cord entanglement, and especially excessively long umbilical cord were identified as independent risk factors for TKUC. TKUC had a minimal impact on the newborn's condition at birth, while it's associated with higher rates of cesarean section and preterm birth.

Knots of the umbilical cord: Incidence, diagnosis, and management

Knot(s) of the umbilical cord have received emphasis because the clinical assessments and sonographic literature show a crucial role in fetal outcomes. The true umbilical cord knot could be a knot in a singleton pregnancy or an entanglement of two umbilical cords in monoamniotic twins. Clinical manifestations are almost silent, which can raise clinical challenges. They worsen outcomes, and the pathology can be easily missed during prenatal visits because ultrasonographers do not pay attention to the cord during an obstetric ultrasound scan. However, most medical centers now have ultrasound machines that improve fetal assessment. The umbilical cord should be routinely evaluated during a fetal assessment, and suspicion of an umbilical cord knot can be more frequently diagnosed and is detected only incidentally. Clinical outcome is usually good but depends on the knot's characteristics and if it is tight or loose. In this review, we discuss pathophysiology, the theories on formation, the main risk factors, ultrasound signs and findings, different opinions in the management, and features of pregnancy outcomes feature.

Impact of cord entanglement on perinatal outcome

OBJECTIVE

To evaluate the impact of umbilical cord entanglement around various fetal organs on perinatal outcomes.

STUDY DESIGN

A retrospective population-based study of all deliveries between 1988 and 2016 at a tertiary medical center. Immediate perinatal outcomes of newborns with and without cord entanglement were compared.

RESULTS

The prevalence of any cord entanglement in our population was 16.62 % (45,312 cases out of 272,713 deliveries during the study period). Cord entanglement was found to be significantly associated with antepartum fetal death (OR = 2.13, 95 % CI 1.77-2.57, p < 0.001) and one-minute Apgar score less than 7 (OR = 1.21, 95 % CI 1.16-1.27, p < 0.001). There was no association between cord entanglement and small for gestational age (SGA) babies.

CONCLUSION

Cord entanglement is associated with antepartum fetal death, but not with SGA.

The benefit of active management in true knot of the umbilical cord: a retrospective study

PURPOSE

To compare perinatal outcomes between active and routine management in true knot of the umbilical cord (TKUC).

METHODS

A retrospective study of singletons born beyond 22 6/7 weeks with TKUC. Active management included weekly fetal heart rate monitoring(FHRM) ≥ 30 weeks and labor induction at 36-37 weeks. Outcomes in active and routine management were compared, including composite asphyxia-related adverse outcome, fetal death, labor induction, Cesarean section (CS) or Instrumental delivery due to non-reassuring fetal heart rate (NRFHR), Apgar5 score < 7, cord Ph < 7, neonatal intensive care unit (NICU) admission and more.

RESULTS

The Active (n = 59) and Routine (n = 1091) Management groups demonstrated similar rates of composite asphyxia-related adverse outcome (16.9% vs 16.8%, p = 0.97). Active Management resulted in higher rates of labor induction < 37 weeks (22% vs 1.7%, p < 0.001), CS (37.3% vs 19.2%, p = 0.003) and NICU admissions (13.6% vs 3%, p < 0.001). Fetal death occurred exclusively in the Routine Management group (1.8% vs 0%, p = 0.6).

CONCLUSION

Compared with routine management, weekly FHRM and labor induction between 36 and 37 weeks in TKUC do not appear to reduce neonatal asphyxia. In its current form, active management is associated with higher rates of CS, induced prematurity and NICU admissions. Labor induction before 37 weeks should be avoided.

Characteristics and treatment for severe postpartum haemorrhage in different midwifery hospitals in one district of Beijing in China: an institution-based, retrospective cohort study

OBJECTIVE

To identify the characteristics and treatment approaches for patients with severe postpartum haemorrhage (SPPH) in various midwifery institutions in one district in Beijing, especially those without identifiable antenatal PPH high-risk factors, to improve regional SPPH rescue capacity.

DESIGN

Retrospective cohort study.

SETTING

This study was conducted at 9 tertiary-level hospitals and 10 secondary-level hospitals in Haidian district of Beijing from January 2019 to December 2022.

PARTICIPANTS

The major inclusion criterion was SPPH with blood loss ≥1500 mL or needing a packed blood product transfusion ≥1000 mL within 24 hours after birth. A total of 324 mothers with SPPH were reported to the Regional Obstetric Quality Control Office from 19 midwifery hospitals.

OUTCOME MEASURES

The pregnancy characteristics collected included age at delivery, gestational weeks at delivery, height, parity, delivery mode, antenatal PPH high-risk factors, aetiology of PPH, bleeding amount, PPH complications, transfusion volume and PPH management. SPPH characteristics were compared between two levels of midwifery hospitals and their association with antenatal PPH high-risk factors was determined.

RESULTS

SPPH was observed in 324 mothers out of 106 697 mothers in the 4 years. There were 74.4% and 23.9% cases of SPPH without detectable antenatal PPH high-risk factors in secondary and tertiary midwifery hospitals, respectively. Primary uterine atony was the leading cause of SPPH in secondary midwifery hospitals, whereas placental-associated disorders were the leading causes in tertiary institutions. Rates of red blood cell transfusion over 10 units, unscheduled returns to the operating room and adverse PPH complications were higher in patients without antenatal PPH high-risk factors. Secondary hospitals had significantly higher rates of trauma compared with tertiary institutions.

CONCLUSION

Examining SPPH cases at various institutional levels offers a more comprehensive view of regional SPPH management and enhances targeted training in this area.

Are reduced fetal movements "merely" a maternal perception or truly a reflection of umbilical cord complications? A clinical trial

OBJECTIVE

To characterize obstetric outcomes and the association with umbilical cord (UC) complications among women complaining of reduced fetal movements (RFMs).

METHODS

This retrospective cohort compared women with a perception of RFMs within 2 weeks prior to delivery with women who reported no changes in fetal movements in terms of maternal characteristics and neonatal outcomes. A primary outcome of UC complications at delivery was defined. Multivariable regression analysis was performed to identify independent associations with RFMs and UC complications.

RESULTS

In all, 46 103 women were included, 2591 (5.6%) of whom reported RFMs and 43 512 (94.4%) in the control group. Compared with controls, the RFM group was more likely to be nulliparous (42.6% vs 32.2%, P < 0.001), smokers (6.4% vs 5.4%, P = 0.029), or obese (body mass index >30) (16.4% vs 11.6%, P < 0.001). They were also more likely to have an anterior placenta (56.2% vs 51.8%, P < 0.001) and poly/oligohydramnios (0.7% vs 0.4%, P = 0.015 and 3.6% vs 2.1%, P < 0.001, respectively). Induction of labor was more common in the RFM group (33.9% vs 19.7%, P < 0.001), as well as meconium (16.8% vs 15.0%, P = 0.026) and vacuum extractions (10.1% vs 8.0%, P < 0.001). Higher rates of stillbirth and the severe composite neonatal outcome were observed in the RFM group (1.5% vs 0.2%, P < 0.001 and 0.6% vs 0.3%, P = 0.010, respectively). The RFM group was characterized by higher rates of triple nuchal cord (P = 0.015), UC around body or neck (32.2% vs 29.6%, P = 0.010), and true knot (2.3% vs 1.4%, P = 0.002). Multivariable logistic regression found RFMs to be independently associated with triple nuchal cord and with a true cord knot. A sub-analysis including only cases of stillbirth (n = 127) revealed even higher rates of UC complications: 7% of all stillbirths presented with a true cord knot (20% true knots were found in stillbirths preceded by RFMs vs 6.1% in stillbirth cases without RFMs). Additionally, 33.8% of all stillbirths presented with nuchal cord (40% preceded by RFMs vs 33.3% without RFMs).

CONCLUSIONS

RFMs are associated with increased risk of UC complications observed at delivery, as well as increased risk of stillbirth and neonatal adverse outcomes.

Clinical significance of true umbilical cord knot: a propensity score matching study

OBJECTIVE

True umbilical cord knot (TUCK) is a rare finding that often leads to intensified surveillance and patient anxiety. This study sought to evaluate the incidence, risk factors, and obstetric and neonatal outcomes of TUCK.

METHODS

A retrospective cohort study was conducted at a tertiary university medical center in 2007-2019. Patients with singleton pregnancies diagnosed postnatally with TUCK were identified and compared to women without TUCK for obstetric and neonatal outcomes using propensity score matching (PSM).

RESULTS

TUCK was diagnosed in 780 of the 96,766 deliveries (0.8%). Women with TUCK were older than those without TUCK (32.57 vs. 31.06 years, P < 0.001) and had higher gravidity (3 vs. 2, P < 001) and a higher rate of prior stillbirth (1.76% vs. 0.43%, P < 0.01). Following covariate adjustment, 732 women with TUCK were compared to 7320 matched controls. TUCK was associated with emergency cesarean delivery due to non-reassuring fetal heart rate (2.54% vs. 4.35%, P = 0.008, OR 1.71, 95%CI 1.14-2.56) and intrapartum meconium-stained amniotic fluid (19.26% vs. 15.41%, P = 0.022, OR 1.31, 95%CI 1.04-1.65). Neonatal outcomes were comparable except for higher rates of 1-min Apgar score < 7 and neonatal seizures in the TUCK group. The stillbirth rate was higher in the TUCK group, but the difference was not statistically significant (1.23% vs 0.62%, P = 0.06, OR 1.96, 95%CI 0.96-4.03).

CONCLUSIONS

TUCK has several identifiable risk factors. Pregnant women with TUCK may cautiously be informed of the relatively low risks of major obstetric or perinatal complications. The lower occurrence of stillbirth in the TUCK group warrants further study.

Machine learning-based placental clusters and their associations with adverse pregnancy outcomes

BACKGROUND

Placental abnormalities have been described in clinical convenience samples, with predominately adverse outcomes. Few studies have described placental patterns in unselected samples.

OBJECTIVE

We aimed to investigate associations between co-occurring placental features and adverse pregnancy outcomes in a prospective cohort of singletons.

METHODS

Data were from the Safe Passage study (U.S. and South Africa, 2007-2015). Before 24 weeks' gestation, participants were randomly invited to donate placental tissue at delivery for blinded, standardised pathological examination. We used hierarchical clustering to construct statistically derived groups using 60 placental features. We estimated associations between the placental clusters and select adverse pregnancy outcomes, expressed as unadjusted and adjusted risk ratios (RRs) and robust 95% confidence intervals (CI).

RESULTS

We selected a 7-cluster model. After collapsing 2 clusters to form the reference group, we labelled the resulting 6 analytic clusters according to the overarching category of their most predominant feature(s): severe maternal vascular malperfusion (n = 117), fetal vascular malperfusion (n = 222), other vascular malperfusion (n = 516), inflammation 1 (n = 269), inflammation 2 (n = 175), and normal (n = 706). Risks for all outcomes were elevated in the severe maternal vascular malperfusion cluster. For instance, in unadjusted analyses, this cluster had 12 times the risk of stillbirth (RR 12.07, 95% CI 4.20, 34.68) and an almost doubling in the risk of preterm delivery (RR 1.93, 95% CI 1.27, 2.93) compared with the normal cluster. Small infant size was more common among the abnormal clusters, with the highest unadjusted RRs observed in the fetal vascular malperfusion cluster (small for gestational age birth RR 2.99, 95% CI 2.24, 3.98, head circumference <10th percentile RR 2.86, 95% CI 1.60, 5.12). Upon adjustment for known risk factors, most RRs attenuated but remained >1.

CONCLUSION

Our study adds to the growing body of epidemiologic research, finding adverse pregnancy outcomes may occur through etiologic mechanisms involving co-occurring placental abnormalities.

True Knot of the Umbilical Cord and Associated Adverse Perinatal Outcomes: A Case Series

An actual knot that forms during pregnancy is known as a true knot of the umbilical cord (TKUC) which is seen in 0.3% to 1.2% of pregnancies. TKUC is noteworthy because it can lead to a variety of adverse perinatal outcomes, including infants with low Apgar scores, small for gestational age (SGA) fetuses, fetal hypoxia, and also in some cases fetal death. Here, we present instances of TKUC of three patients and the various associated perinatal outcomes.

Association of placental and umbilical cord characteristics with cerebral palsy: national cohort study

OBJECTIVES

Cerebral palsy (CP) is a group of movement disorders usually diagnosed in childhood. A substantial proportion are thought to be caused by antenatal events. Abnormalities of the umbilical cord and placenta are associated with an increased risk of adverse neonatal outcomes, but it is unclear whether these conditions also carry an increased risk of CP. We aimed to determine whether abnormalities of the umbilical cord or placenta are associated with CP and assess if these associations differ by sex of the child or gestational age at birth.

METHODS

We performed a national cohort study by linking data from The Medical Birth Registry of Norway with other national registries. All liveborn singletons born between 1999 and 2017 (n = 1 087 486) were included and followed up until the end of 2019. Diagnoses of CP were provided by the Norwegian National Insurance Scheme and the Norwegian Patient Register. We used generalized estimating equations and multilevel log binomial regression to calculate relative risks (RR), adjusted for year of birth, and stratified analyses were carried out based on sex and gestational age at birth. Exposures were abnormal umbilical cord (velamentous or marginal insertion, single umbilical artery (SUA), knots and entanglement), and placental abnormalities (retained placenta, placental abruption and previa).

RESULTS

A total of 2443 cases with CP (59.8% males) were identified. Velamentous cord insertion (adjusted RR (aRR), 2.11 (95% CI, 1.65-2.60)), cord knots (aRR, 1.53 (95% CI, 1.15-2.04)) and placental abnormalities (placenta previa (aRR, 3.03 (95% CI, 2.00-4.61)), placental abruption (aRR, 10.63 (95% CI, 8.57-13.18)) and retained placenta (aRR, 1.71 (95% CI, 1.32-2.22))) carried an increased risk of CP. Velamentous cord insertion was associated with CP regardless of gestational age or sex. A retained placenta was associated with a 2-fold increased risk for CP in males, while the associations of SUA and cord knot with CP were significant only among females.

CONCLUSIONS

The detection of placental and umbilical cord abnormalities may help identify children at increased risk of CP. The associations between placental or umbilical cord abnormalities and the risk of CP do not vary substantially with gestational age at birth or sex of the child. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

A misdiagnosed case of a 150-cm umbilical cord coiled twice around the fetal neck with a true cord knot: A rare Syrian case report

The normal umbilical cord is a crucial component during pregnancy, but sometimes it could become compromised due to some abnormalities such as excessive long umbilical cord, and though they usually end up with a healthy baby, they may lead to severe consequences. Excessive long umbilical cords are found in 4% of pregnancies and represent a risk factor for nuchal cords and true knots. We report a case of a 37-year-old Syrian pregnant woman who presented to the hospital at 37 weeks of gestation asking for a C-section for a fear of ambiguous ultrasound findings that have been interpreted as fetal malformation. At delivery, a healthy baby was born with a 150-cm umbilical cord, a true knot, and double-looped nuchal cords; the formation of the loops and the knot had been attributed to the elongated cord. Besides, ultrasound imaging could sometimes be deceptive and lead to unnecessary interventions; therefore, cord anomalies should always be kept in mind because they do not always represent a justification for a C-section.

Etiological subgroups of term small-for-gestational-age and childhood health outcomes

BACKGROUND

Small-for-gestational-age (SGA) has a heterogeneous etiology. Our study aimed to examine the childhood health outcomes of etiology-distinct term SGA subgroups.

METHODS

Data from the Collaborative Perinatal Project were used. The etiological factors of SGA were categorized into five groups: maternal, fetal, placental, environmental and physiological factors. Primary child outcomes included low IQ and growth restriction. A total of 8417 term infants were eligible.

RESULTS

Compared with AGA, SGA children due to fetal factors had the highest risk of low IQ (aOR = 1.94, 95% CI: 1.45-2.59). SGA infants due to physiological factors had the highest risk of growth restriction (aOR = 6.04, 95% CI: 3.93-9.27). SGA children had a higher risk of growth restriction with the aOR ranging from 3.05 (95% CI: 2.36-3.96) to 5.77 (95% CI: 4.29-7.75) for the number of risk factors that the SGA infants had from 1 to 5. SGA children with any risk factor were associated with a higher risk of lower IQ with the aOR ranging from 1.59 (95% CI: 1.31-1.94) to 1.96 (95% CI: 1.50-2.55). SGA without the five types of etiologies was not associated with adverse child outcomes except for growth restriction (aOR = 3.82, 95% CI: 2.62-5.55).

CONCLUSION

Term SGA of different etiologies may lead to different child health outcomes.

IMPACT

Our study found that SGA of different etiologies may lead to different child health outcomes. Compared with AGA, SGA children due to fetal factors had the highest risk of low IQ. SGA infants due to physiological factors had the highest risk of growth restriction. SGA babies should not be treated the same. In the era of precision medicine, our findings may help pediatricians and parents better manage SGA babies according to different etiologies and the number of risk factors.

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.

Risk factors and recurrence of cause-specific postpartum hemorrhage: A population-based study

OBJECTIVE

To explore risk profiles of the different types of postpartum hemorrhage (PPH >500ml or severe PPH >1500ml) and their recurrence risks in a subsequent delivery.

METHODS

With data from The Medical Birth Registry of Norway and Statistics Norway we performed a population-based cohort study including all singleton deliveries in Norway from 1967-2017. Multilevel logistic regression was used to calculate odds ratio (OR), with 95% confidence interval (CI), with different PPH types (PPH >500ml or PPH >1500ml (severe PPH) combined with retained placenta, uterine atony, obstetric trauma, dystocia, or undefined cause) as outcomes.

RESULT

We identified 277 746 PPH cases of a total of 3 003 025 births (9.3%) from 1967 to 2017. Retained placenta (and/or membranes) was most often registered as severe PPH (29.3%). Maternal, fetal, and obstetric characteristics showed different associations with the PPH types. Male sex of the neonate was associated with reduced risk of PPH. This effect was strongest on PPH due to retained placenta (adjusted OR, (aOR): 0.80, 95% CI 0.78-0.82), atony (aOR 0.92, 95% CI: 0.90-0.93) and PPH with undefined cause (aOR 0.96, 95% CI: 0.95-0.97). Previous cesarean section showed a strong association with PPH due to dystocia (aOR of 13.2, 95% CI: 12.5-13.9). Recurrence risks were highest for the same type: PPH associated with dystocia (aOR: 6.8, 95% CI: 6.3-7.4), retained placenta and/or membranes (aOR: 5.9, 95% CI: 5.5-6.4), atony (aOR: 4.0, 95% CI: 3.8-4.2), obstetric trauma (aOR: 3.9, 95% CI: 3.5-4.3) and PPH of undefined cause (aOR: 2.2, 95% CI: 2.1-2.3).

CONCLUSION

Maternal, fetal and obstetric characteristics had differential effects on types of PPH. Recurrence differed considerably between PPH types. Retained placenta was most frequently registered with severe PPH, and showed strongest effect of sex; delivery of a boy was associated with lower risk of PPH. Previous cesarean increased the risk of PPH due to dystocia.

Adverse Perinatal Outcomes of True Knot of the Umbilical Cord: A Case Series and Review of Literature

A true knot of the umbilical cord (TKUC) is an actual knot formed in pregnancy. It is seen in approximately 0.3%-1.2% of all pregnancies. True knots are of significance as they can cause a wide spectrum of adverse perinatal outcomes like small for gestational age (SGA) fetus, low appearance, pulse, grimace, activity, and respiration (Apgar) score at birth, fetal hypoxia, and even fetal demise.

Here, we report a case series of three patients with TKUC and the varied adverse perinatal outcomes associated with them. A low-risk primigravida at term gestation had a suspicious non-stress test (NST). Repeat NST after maternal resuscitation became pathological. Emergency cesarean delivery was performed in view of pathological NST persisting despite intrauterine resuscitation. A healthy male baby weighing 2920 g was delivered, and the umbilical cord had a true knot.

A multigravida at 33 + 3 weeks of gestation was referred with fetal growth restriction (FGR). Color Doppler examination showed absent end-diastolic flow (AEDF) in the umbilical artery (UA). Cesarean delivery was performed in view of FGR stage two with AEDF in the UA at 34 weeks of gestation as per the Barcelona criteria. A male baby weighing 1505 g was delivered. The umbilical cord had a true tight knot. The baby had an Apgar score of 7 at one minute after birth but was shifted to the neonatal intensive care unit (NICU) in view of low birth weight and prematurity. The baby slowly gained weight and was discharged from NICU after 15 days in stable condition.

A multigravida at 32 weeks of gestation was referred with intrauterine fetal demise. Ultrasonography confirmed the presence of a single intrauterine dead fetus corresponding to 30 + 4 weeks of gestation with an estimated fetal weight (EFW) of 1633 g, amniotic fluid index (AFI) equal to nine, and presence of Spalding’s sign. Induction of labor was done, and she expelled a dead macerated male fetus weighing 1825 g. The infantogram was normal. A true umbilical cord knot was found.

The umbilical cord is the source of fetal blood supply; therefore, any cord abnormality can have a significant impact on the fetal outcome. There are various factors that can predispose to TKUC, such as polyhydramnios, increased cord length, monoamniotic twins, male baby, grand multiparity, small fetus, and amniocentesis. TKUC can lead to various adverse outcomes in pregnancy and labor like SGA fetus, low Apgar score at birth, fetal hypoxia, and fetal demise. TKUC increases the risk of fetal demise by as much as four times.

With the development of advanced techniques such as three-dimensional/four-dimensional color Doppler ultrasounds, TKUC can be diagnosed antenatally in the form of a four-leaf-clover, a “hanging-noose sign,” or by an unusual multicolor pattern in the cord. The prenatal detection rate of TKUC is only 12%. It mostly remains undetected unless visualized incidentally. Although TKUC is not rare and can have serious outcomes, the importance of its antenatal diagnosis has not been determined. It should be suspected in patients with risk factors, and emphasis should be placed on its antenatal diagnosis on ultrasonography to avoid obstetric disasters in otherwise low-risk females. Though there is no specific management of these cases, a good clinical outcome can be achieved if TKUC is diagnosed antenatally and monitored closely until fetal maturity is attained.

Antenatal Detection of True Knot in the Umbilical Cord - How Accurate Can We Be?

BACKGROUND

Umbilical cord knot (UCK) is associated with increased risk of fetal death, but is usually diagnosed only after delivery. Our objective was to examine the accuracy of prenatal ultrasound in the diagnosis of UCK and the outcomes of these pregnancies.

METHODS

A prospective study was performed on 56 patients in which UCK was suspected during a routine level-II anatomical scan (study group). Data included demographics, pregnancy outcome, and short-term neonatal follow-up. The control group included pregnant women with normal pregnancy without UCK in a 4:1 ratio matched for gestational age at delivery.

RESULTS

True knot was observed postnatally in 54 out of 56 fetuses (detection rate of 96.4 %). Gestational age at diagnosis of UCK was 22.1 ± 3.1 weeks. The female to male ratio was 1:1 in both groups. Maternal age and parity were significantly higher in pregnancies with UCK compared to controls. The mean gestational age at delivery was 37.1 weeks of gestation in the UCK group. There was no difference in the birthweight percentile. 47 patients (87 %) underwent induction of labor. There were no differences in the rate of cesarean section or Apgar scores. No neonate with UCK needed ventilation. None suffered from seizures and none needed brain imaging. There were no cases of fetal or neonatal death in the pregnancies with UCK.

CONCLUSION

There is a high detection rate of UCK during targeted scan of the umbilical cord performed during the level-II anatomical scan. Careful pregnancy follow-up and early term delivery may result in excellent obstetrical outcomes.

Umbilical Cord Knots: Is the Number Related to Fetal Risk?

True knots of the umbilical cord (UC) are a rare occurrence and are reported in 0.4–1.2% of deliveries. The compression of true knot of the UC can cause obstruction of the fetal circulation, leading to intra-uterine growth retardation or fetal death. Predisposing factors for the genesis of the true UC knot are numerous and include all the conditions, which lead to a relatively large uterine volume. This situation may predispose to free and excessive fetal movements. Although not all true knots lead to perinatal complications, they have been associated with adverse pregnancy outcomes, including fetal distress, fetal hypoxia, intra-uterine growth restriction (IUGR), long-term neurological damage, caesarean delivery and stillbirth. We present a rare case of operative delivery with vacuum in a multiparous woman at term of pregnancy with a double true knot of the UC. As in most cases, the diagnosis was made after delivery, as there were no fetal symptoms during pregnancy. Some authors assume that 3D power sonography may be useful in the diagnosis of true UC knots. However, 3D power Doppler cannot be considered as a definitive method. There are no specific prenatal indications to induce the physician to look for ultrasound signs suggestive of umbilical true knot. Some studies argue that cases of fetal death and fetal risk are directly related to the number of knots. We also support this thesis, even if further observational and retrospective studies are needed to demonstrate it.

Placental lesions and differential expression of pro-and anti-angiogenic growth mediators and oxidative DNA damage marker in placentae of Ghanaian suboptimal and optimal health status pregnant women who later developed preeclampsia

Background

Angiogenic growth mediators (AGMs) and oxidative stress (OS) both play essential roles in normal placental vascular development and as such, placental alterations in these factors contribute to pre-eclampsia (PE). Suboptimal health status (SHS), an intermediate between health and disease, has been associated with imbalanced AGMs and OS biomarkers. Thus, SHS pregnant women may be at increased risk of developing PE and may present abnormal placental alteration and expression of AGMs and OS compared to optimal health status (OHS) pregnant women. We examined the histopathological morphology, immunohistochemical expression of AGMs antibodies and oxidative DNA damage marker in the placentae of SHS and OHS pregnant women who developed early-onset PE (EO-PE) and late-onset (LO-PE) compared to normotensive pregnancy (NTN-P).

Methods

This nested case-control study recruited 593 singleton normotensive pregnant women at baseline (10–20 weeks gestation) from the Ghanaian Suboptimal Health Status Cohort Study (GHOACS) undertaken at the Komfo Anokye Teaching Hospital, Ghana. Socio-demographic, clinical and obstetrics data were collected, and a validated SHS questionnaire-25 (SHSQ-25) was used in classifying participants into SHS (n = 297) and OHS (n = 296). Participants were followed until the time of PE diagnosis and delivery (32–42 weeks gestation). Blood samples were collected at the two-time points and were assayed for AGMs; soluble fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PIGF), vascular endothelial growth factor-A (VEGF-A), and soluble endoglin (sEng), and OS biomarkers; 8-hydroxydeoxyguanosine (8-OHdG), 8-epiprostaglandinF2-alpha (8- epi-PGF2α) and total antioxidant capacity (TAC) using ELISA. Placental samples were collected for histopathological and immunohistochemical analysis.

Results

Of the 593 pregnant women, 498 comprising 248 SHS and 250 OHS women returned for delivery and were included in the final analysis. Of the 248 SHS women, 56, 97 and 95 developed EO-PE, LO-PE and NTN-P, respectively, whereas 14, 30 and 206 of the 250 OHS mothers developed EO-PE, LO-PE and NTN-P, respectively. At baseline, SHS_NTN pregnant women had a significant imbalance in AGMs and OS biomarkers compared to OHS_NTN pregnant women (p<0.0001). At the time of PE diagnosis, SHS_NTN-P women who developed EO-PE, LO-PE, and NTN-P had lower serum levels of P1GF, VEGF-A and TAC and correspondingly higher levels of sEng, sFlt-1, 8-epiPGF2α, and 8-OHdG than OHS-NTN-P women who developed EO-PE and LO-PE, NTN-P (p<0.0001). A reduced placental size, increased foetal/placental weight ratio, and a significantly higher proportion of fibrinoid necrosis, infarction, villous fibrin, syncytial knots, calcification, chorangiosis, tunica media/vascular wall hypertrophy and chorioamnionitis was associated with the SHS group who developed PE (EO-PE>LO-PE) more than OHS groups who developed PE (EO-PE>LO-PE) when all were compared to NTN-P (p<0.0001). The intensity of antibody expression of PIGF and VEGF-A were significantly reduced, whereas Flt-1, Eng and 8-OHdG were significantly increased in placentae from SHS-pregnant women who developed EO-PE>LO-PE more than OHS- pregnant women who developed EO-PE>LO-PE when all were compared to NTN-P (p<0.0001).

Conclusion

Increased lesions, oxidative DNA damage, and imbalanced expression between pro-and anti-AGMs are associated more with SHS-embodied PE placentae rather than OHS-embodied PE subtypes, thus potentially allowing differential evaluation of PE.

Recurrence of postpartum hemorrhage, maternal and paternal contribution, and the effect of offspring birthweight and sex: a population-based cohort study

Purpose

This study examines individual aggregation of postpartum hemorrhage (PPH), paternal contribution and how offspring birthweight and sex influence recurrence of PPH. Further, we wanted to estimate the proportion of PPH cases attributable to a history of PPH or current birthweight.

Methods

We studied all singleton births in Norway from 1967 to 2017 using data from Norwegian medical and administrational registries. Subsequent births in the parents were linked. Multilevel logistic regression was used to calculate odds ratios (ORs) with 95% confidence intervals (CI) for PPH defined as blood loss > 500 ml, blood loss > 1500 ml, or the need for blood transfusion in parous women. Main exposures were previous PPH, high birthweight, and fetal sex. We calculated adjusted population attributable fractions for previous PPH and current high birthweight.

Results

Mothers with a history of PPH had three- and sixfold higher risks of PPH in their second and third deliveries, respectively (adjusted OR 2.9; 95% CI 2.9–3.0 and 6.0; 5.5–6.6). Severe PPH (> 1500 ml) had the highest risk of recurrence. The paternal contribution to recurrence of PPH in deliveries with two different mothers was weak, but significant. If the neonate was male, the risk of PPH was reduced. A history of PPH or birthweight ≥ 4000 g each accounted for 15% of the total number of PPH cases.

Conclusion

A history of PPH and current birthweight exerted strong effects at both the individual and population levels. Recurrence risk was highest for severe PPH. Occurrence and recurrence were lower in male fetuses, and the paternal influence was weak.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00404-021-06374-3.

Biomarkers of Inflammation and Redox Imbalance in Umbilical Cord in Pregnancies with and without Preeclampsia and Consequent Perinatal Outcomes

OBJECTIVE

To compare redox imbalance and inflammation biomarkers in umbilical cords from pregnancies with and without preeclampsia (PE) and to analyse their relationships with perinatal outcomes.

METHODS

A controlled cross-sectional study was conducted in Maceió, Alagoas, Brazil, that involved pregnant women with PE and a group of women without the disease, through the application of a standardized questionnaire. After delivery, umbilical cord samples were collected to measure antioxidant defense, products from oxidative damage, and inflammation biomarkers such as myeloperoxidase (MPO), interleukin- (IL-) 6, IL-8, IL-10, and tumor necrosis factor-alpha (TNF-α). Statistical analyses were performed using Stata version 13.0 software and IBM Statistical Package for the Social Sciences (SPSS) 20.0, adopting a 95% confidence level (α = 0.05), with the chi-square test, the Wilcoxon-Mann-Whitney test, and the multinomial and Poisson regression tests.

RESULTS

One hundred PE pregnant women and 50 women without the disease were studied. The umbilical cords from PE pregnancies showed higher levels of reduced glutathione (GSH) (p ≤ 0.001), glutathione peroxidase (GPx) (p = 0.016), and malondialdehyde (MDA) (p = 0.028) and lower levels of IL-6 (p = 0.030) and TNF-α (p ≤ 0.001) than the other group, with some associations among these biomarkers with perinatal outcomes.

CONCLUSION

The higher levels of GSH and GPx, in addition to the lower levels of IL-6 and TNF-α, found in the PE umbilical cord, may result from adaptive mechanisms to maintain the oxidative and inflammatory balance; however, despite these changes, the damage to the cell membranes was not minimized, as the MDA level was higher in women with PE than in women without the disease. This implies that a redox imbalance is present, confirming that other physiological and adaptive mechanisms are being activated to preserve foetal health. Therefore, the present work unveils an important role of the umbilical cord in controlling redox imbalance and inflammation in PE pregnancies. Our results reinforce the necessity for continuous research on GSH as a protective compound for the perinatal outcome, especially in PE women.

The perils of true knot of the umbilical cord: antepartum, intrapartum and postpartum complications and clinical implications

BACKGROUND

True knot of the umbilical cord (TKUC) is found in 0.3-2.1% of pregnancies and is associated with an increased risk of adverse perinatal outcomes.

METHODS

A retrospective cohort study including all singleton pregnancies delivered from 2011 to 2019 was performed. Diagnosis of TKUC was made postnatally, immediately after delivery of the baby. Comparison was made between pregnancies with and without TKUC regarding maternal, fetal and neonatal adverse outcome.

RESULTS

Overall, 867/85,541 (1%) pregnancies were diagnosed with TKUC. Maternal age, BMI, gravidity and parity were significantly higher in pregnancies with TKUC as well as higher rate of induction of labor, meconium-stained amniotic fluid, and delivery prior to 37 weeks. The rate of cesarean deliveries due to non-reassuring-fetal monitor was significantly higher in pregnancies with TKUC. Overall, there were 2.5% IUFD in pregnancies with TKUC vs. 1% in pregnancies without TKUC (p < 0.001). Importantly, the rate of IUFD prior to 37 weeks of gestation was not significantly higher in the group with TKUC, however, the rate of IUFD after 37 weeks of gestation was 10 folds higher in fetuses with TKUC, 0.9% vs. 0.08% (p < 0.001). Significantly, more neonates with TKUC needed phototherapy or suffered from hypoglycemia. There were no differences in the 5 min Apgar scores, admission to the NICU and number of days of hospitalization.

CONCLUSION

Pregnancies complicated with TKUC are associated with a tenfold higher risk of IUFD beyond 37 weeks of gestation. To the results of this study suggest that it would be prudent to induce labor around 37 weeks of gestation in pregnancies with prenatal diagnosis of TKUC. It may be warranted to use continuous fetal monitoring during labor and delivery in those cases were antenatal diagnosis of TKUC is made.

Magnitude and Determinants of Adverse Perinatal Outcomes in Tefera Hailu Memorial Hospital, Sekota Town, Northern Ethiopia

Background

Of 133 million births globally, 3.7 million died in the neonatal period and 3 million are stillborn. The perinatal mortality rate in Ethiopia is 46 per 1000 pregnancies. However, area-specific information is limited in this regard. Therefore, this study aimed to determine the magnitude and determinants of adverse perinatal outcomes in Northern Ethiopia.

Method

An institution-based cross-sectional study was conducted by reviewing the medical records of mothers who gave birth between September 2015 and August 2016. The completeness and consistency of data were checked. Descriptive statistics were computed. A multinomial logistic regression model was fitted to identify determinants of adverse perinatal outcomes. Odds ratio with 95%CI was used and variables that had a P-value of < 0.05 in the final model were considered statistically significant.

Result

The magnitude of adverse perinatal outcomes was 214/799(27.47 %). Out of that, 10.8% had a perinatal mortality outcome, and 16.7% had a perinatal morbidity. Not using modern contraceptives(AOR = 1.7, 95% CI: 1.1-2.7), labor induction or augmentation(AOR = 3.0, 95% CI: 1.2-7.8), obstetric complications(AOR = 2.2, 95% CI: 1.1-4.5), attending antenatal care(AOR = 0.4, 95% CI: 0.2-0.8), primigravida (AOR = 0.5, 95% CI: 0.3-0.9), had no history of medical illness(AOR = 0.5, 95% CI: 0.3-0.8), and urban residency(AOR = 1.9, 95% CI, 1.1-2.9) were the significant determinants of perinatal outcome.

Conclusion

The magnitude of adverse perinatal outcomes was considerable and 1 in 5 neonates either had morbidity conditions or died. Improving family planning utilization, ANC, referral linkage, and management of obstetric complications could help to reduce the undesirable consequences of perinatal outcomes.

Maternal obesity and stillbirth at term; placental pathology-A case control study

OBJECTIVE

The aim was to explore the potential role of the placenta for the risk of stillbirth at term in pregnancies of obese women.

METHODS

This was a case-control study comparing placental findings from term stillbirths with placental findings from live born infants. Cases were singleton term stillbirths to normal weight or obese women, identified in the Stockholm stillbirth database, n = 264 and n = 87, respectively. Controls were term singletons born alive to normal weight or obese women, delivered between 2002-2005 and between 2018-2019. Placentas were compared between women with stillborn and live-born infants, using logistic regression analyses.

RESULTS

A long and hyper coiled cord, cord thrombosis and velamentous cord insertion were stronger risk factors for stillbirth in obese women compared to normal weight women. When these variables were adjusted for in the logistic regression analysis, also adjusted for potential confounders, the odds ratio for stillbirth in obese women decreased from 1.89 (CI 1.24-2.89) to 1.63 (CI 1.04-2.56).

CONCLUSION

Approximately one fourth of the effect of obesity on the risk of stillbirth in term pregnancies is explained by umbilical cord associated pathology.

What Obstetricians Need to Know About Placental Pathology

The placenta can serve as a valuable source of information about maternal and fetal conditions during the pregnancy; however, the abilities to perform a preliminary gross examination and interpret a placental pathology report are variable among obstetricians. This article discusses the indications for placental submission to pathology; the essentials of gross examination, including elements that should be performed in the delivery suite; and the most common and clinically relevant histologic findings that may be encountered in the report.

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.

Effect of umbilical cord length on early fetal biomechanics

The umbilical cord suspends the fetus within the amniotic cavity, where fetal dynamics is one of its many functions. Hence, the umbilical cord is a viable index in determining fetal activity. Fetal movements result in mechanical loads that are fundamental for fetal growth. At present, mechanical environment during early human fetal development is still largely unknown. To determine early fetal movement dynamics at given physiological (0.060 m) and pathological umbilical cord lengths (0.030 m, 0.020 m, 0.017 m and 0.014 m) a 2D computational model was created to simulate dynamic movement conditions. Main findings of this computational model revealed the shortest umbilical cord length (0.014 m) with a 6(10-6)N, twitch force amplitude had a two-fold increase on linear velocity (0.12 m/s) in comparison with other lengths (0.05m/s). Moreover, umbilical cord length effect presented an increasing exponential tension on the fetus body wall from longest to shortest, from 0 N in the control length to 0.05 N for the shortest umbilical cord. Last, tension was always present over a period of time for the shortest cord (0.03 N to 0.08 N). Collectively, for all variables evaluated the shortest umbilical cord (0.014 m) presented remarkable differences with other lengths in particular with the second shortest umbilical cord (0.017 m), suggesting a 0.003 m difference represents a greater biomechanical effect. In conclusion, this computational model brings new insights required by clinicians, where the magnitude of these loads could be associated with different pathologies found in the clinic.

Sex-specific reference ranges of cerebroplacental and umbilicocerebral ratios: longitudinal study

OBJECTIVES

Observational studies have shown that low cerebroplacental ratio (CPR) values predict an increased risk of adverse perinatal outcome. The inverse ratio, i.e. the umbilicocerebral ratio (UCR), has been suggested to be a better predictor as it rises with increasing degree of fetal compromise. However, longitudinal reference ranges for UCR have not been established, and whether gestational-age-dependent changes in CPR or UCR differ between male and female fetuses has not been studied. Thus, the aims of this study were to investigate sex-specific, gestational-age-associated serial changes in CPR and UCR during the second half of pregnancy and to establish longitudinal reference ranges.

METHODS

This was a secondary analysis of prospectively collected data from a dual-center longitudinal observational cohort study of low-risk singleton pregnancies. Doppler blood-flow velocity waveforms were obtained serially from the umbilical artery (UA) and fetal middle cerebral artery (MCA) from 19-41 weeks' gestation, and pulsatility indices (PIs) were determined. CPR and UCR were calculated as the ratios MCA-PI/UA-PI and UA-PI/MCA-PI, respectively. The course and outcome of pregnancies were recorded, and the sex of the fetus was determined after delivery. Reference intervals for CPR and UCR were constructed using multilevel modeling, and gestational-age-specific Z-scores in male and female fetuses were compared.

RESULTS

Of a total of 299 pregnancies enrolled, 284 (148 male and 136 female fetuses) were included in the final analysis, and 979 paired measurements of UA-PI and MCA-PI were used to construct sex-specific longitudinal reference intervals. The relationship of both CPR and UCR with gestational age was U-shaped, but in opposite directions. There was a small but significant difference in Z-scores of CPR and UCR between male and female fetuses throughout the second half of pregnancy (P = 0.007).

CONCLUSIONS

We have established longitudinal reference ranges for CPR and UCR suitable for serial monitoring, with the possibility of refining assessment by using fetal sex-specific ranges and conditioning by a previous measurement. The clinical significance of such refinements needs further evaluation. © 2019 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

Two knots in an umbilical cord with seventy centimeter length: A case report

Our case was a newborn with two umbilical knots that delivered 39 weeks gastation and did not experience any developmental disruptions. The risk factors of fetus for true knot formation in the umbilical cord were gender and the umbilical cord size.

Current Perspectives of Prenatal Sonographic Diagnosis and Clinical Management Challenges of True Knot of the Umbilical Cord

Umbilical cord accidents preceding labor are rare. Single and multiple nuchal cords, and true knot(s) of the umbilical cord, are often incidental findings noted at delivery of non-hypoxic non-acidotic newborns without any evidence of subsequent adverse neonatal outcome. In contrast to single nuchal cords, true knots of the umbilical cord, which occur in between 0.04% and 3% of all deliveries, have been associated with a reported 4 to 10 fold increased risk of stillbirth. First reported with real-time ultrasound, current widespread application of color Doppler, power Doppler and three-dimension sonography, has enabled increasingly more accurate prenatal sonographic diagnoses of true knot(s) of the umbilical cord. Reflecting the inability to visualize the entire umbilical cord at prenatal ultrasound assessment, despite detailed second and third-trimester scanning, many occurrences of incidental true knot of the umbilical cord remain undetected and are noted only at delivery. Although prenatal sonographic diagnostic accuracy is increasing, false positive sonographic diagnosis of true knot of the umbilical cord cannot be ruled out with certainty, and must continue to be considered clinically. Notwithstanding the inability to diagnose all true knots, currently there is a clear absence of clinical management guidelines by governing bodies regarding patients in whom prenatal sonographic diagnosis of true knot(s) of the umbilical cord is / are suspected. As a result, in many prenatal ultrasound units, suspected sonographic findings suggestive of or consistent with true knot of the umbilical cord are often disregarded, not documented, and patients are not uniformly informed of this potentially life-threatening condition, which carries an associated considerable risk of stillbirth. This commentary will address current perspectives of prenatal sonographic diagnostic and management challenges associated with true knot(s) of the umbilical cord in singleton pregnancies.

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.

Isolated single umbilical artery and the risk of adverse perinatal outcome and third stage of labor complications: A population-based study

INTRODUCTION

Isolated single umbilical artery (iSUA) refers to single umbilical artery cords with no other fetal malformations. The association of iSUA to adverse outcome of pregnancy has not been consistently reported, and whether iSUA carries increased risk of third stage of labor complications has not been studied. We aimed to investigate the risk of adverse perinatal outcome, third stage of labor complications, and associated placental and cord characteristics in pregnancies with iSUA. A further aim was to assess the risk of recurrence of iSUA and anomalous cord or placenta characteristics in Norway.

MATERIAL AND METHODS

This was a population-based study of all singleton pregnancies with gestational age >16 weeks at birth using data from the Medical Birth Registry of Norway from 1999 to 2014 (n = 918 933). Odds ratios (OR) with 95% confidence intervals were calculated for adverse perinatal outcome (preterm birth, perinatal and intrauterine death, low Apgar score, transferral to neonatal intensive care ward, placental and cord characteristics [placental weight, cord length and knots, anomalous cord insertion, placental abruption and previa]), and third stage of labor complications (postpartum hemorrhage and the need for manual placental removal or curettage) in pregnancies with iSUA, and recurrence of iSUA using generalized estimating equations and logistic regression.

RESULTS

Pregnancies with iSUA carried increased risk of adverse perinatal outcome (OR 5.06, 95% confidence interval [CI] 4.26-6.02) and perinatal and intrauterine death (OR 5.62, 95% CI 4.69-6.73), and a 73% and 55% increased risk of preterm birth and small-for-gestational-age neonate, respectively. The presence of iSUA also carried increased risk of a small placenta, placenta previa and abruption, anomalous cord insertion, long cord, cord knot and third stage of labor complications. Women with iSUA, long cord or anomalous cord insertion in one pregnancy carried increased risk of iSUA in the subsequent pregnancy.

CONCLUSIONS

The presence of ISUA was associated with a more than five times increased risk of intrauterine and perinatal death and with placental and cord complications. The high associated risk of adverse outcome justifies follow up with assessment of fetal wellbeing in the third trimester, intrapartum surveillance and preparedness for third stage of labor complications.

Placental Abnormalities Associated With Childbirth

Pathologists are faced with a variety of problems when considering placental tissue in cases of stillbirth. It is recognized that there are changes which occur following fetal demise and which can complicate the assessment and may coexist with other morphological changes. It is recognized that up to 25% of stillbirths may have a recognizable abnormality causing fetal demise. A systematic review of placental tissue allows many of these disorders to be identified. This review considers macroscopic and microscopic features of placental pathology in stillbirth together with clinicopathological correlation. Stillbirth definitions, general aspects of macroscopic assessment of placentas, placental changes after fetal demise, and some recognizable causes of fetal demise are considered.

DNA methylome of human neonatal umbilical cord: Enrichment of differentially methylated regions compared to umbilical cord blood DNA at transcription factor genes involved in body patterning and effects of maternal folate deficiency or children's sex

The DOHaD (developmental origins of health and disease) hypothesis claims that fetal malnutrition or exposure to environmental pollutants may affect their lifelong health. Epigenetic changes may play significant roles in DOHaD; however, access to human fetuses for research has ethical and technical hurdles. Umbilical cord blood (CB) has been commonly used as an epigenetic surrogate of fetuses, but it does not provide direct evidence of fetal exposure to pollutants. Here, we propose umbilical cord tissue (UC), which accumulates substances delivered to fetuses during gestation, as an alternative surrogate for epigenetic studies on fetuses. To explore the feasibility to examine UC epigenome by deep sequencing, we determined CpG methylation profiles of human postnatal UC by reduced representation bisulfite sequencing. Principal component analysis clearly separated the DNA methylomes of UC and CB pairs isolated from the same newborn (n = 10). Although all UC chromosomes were modestly hypomethylated compared to CB chromosomes, GO analysis revealed strong enrichment of differentially methylated regions (DMRs) at promoter-associated CpG islands in the HOX gene clusters and other genes encoding transcription factors involved in determination of the body pattern. DNA methylomes of UC autosomes were largely comparable between males and females. Deficiency of folate during pregnancy has been suggested to affect fetal DNA methylation to cause congenital anomalies. Whereas DNA methylome of UC was not significantly affected by early-gestational (12 weeks) low levels of maternal plasma folate (< 8 ng/ml, n = 10) compared to controls (>19 ng/mL, n = 10), two specific loci of LTR12C endogenous retroviruses in chromosome 12 were significantly hypermethylated in the low-folate group. Our study suggests that UC is useful as an alternative surrogate for studying environmental effects on DNA methylation in human fetuses, compensating CB by providing additional information about epigenetic regulation of genes involved in developmental body patterning and endogenous retroviruses.

The effect of sampling site on the variability of Umbilical artery PI

INTRODUCTION

To test the hypothesis that standardising the site of sampling of umbilical artery Doppler reduces the variability of umbilical artery Pulsatility Index (PI).

STUDY DESIGN

In this prospective study, pregnant women with a singleton pregnancy and secure dating were invited to participate after 24 weeks of pregnancy. Using recommended technique, umbilical artery PI was measured from the free loop of the umbilical cord and from the para-vesical site by the same examiner at the beginning and the end of ultrasound examination in a state of fetal quiescence, generating four measurements per fetus. Variability of the measurements at the two sampling sites was tested using Pitman test of equality of variance for related samples. The difference between the two sets of measurements were plotted against the mean to generate limits of agreement.

RESULTS

A total of 158 women were recruited. Umbilical artery PI was significantly negatively correlated with the gestational age (r = -0.246 for free loop and -0.262 for para-vesical site, both p < 0.005). The PI at the para-vesical site was significantly higher than in the free loop (p < 0.001). Pitman's test showed that the total variability of umbilical artery PI at the two sites was no different (r = -0.091, p = 0.254).

CONCLUSION

Measurement site contributes to an insignificant proportion to the total variability of the umbilical artery PI measurements. Umbilical artery PI is significantly lower when measured in the free loop as compared to the para-vesical site. Standardising the site of sampling does not improve the repeatability of umbilical artery PI measurement.

Prenatal measurement of umbilical cord length using magnetic resonance imaging

OBJECTIVE

This study aimed to evaluate the feasibility of prenatal measurement of umbilical cord length using magnetic resonance imaging (MRI) in comparison with that of postnatal visual measurement.

STUDY DESIGN

Patients who underwent MRI pelvimetry to rule out cephalopelvic disproportion were recruited. We compared the umbilical cord length measured prenatally using the three-dimensional image of the umbilical cord constructed by AZE virtual place system (AZE^®, Japan) on MRI (M-length) and measured postnatally using the actual length (R-length). The time interval between MRI scan and birth was set within 4 weeks. Patients were divided into normal, long (>90th centile), and short (<10th centile) groups based on the umbilical cord length.

RESULTS

A total of 106 pregnancies were analyzed. MRI was performed at a mean gestational age of 37.4 (34.1-41.7) weeks; the mean gestational age at delivery was 39.4 (36.0-41.8) weeks. M-length and R-length were 67.9 ± 13.6 [mean ± standard deviation] and 57.2 ± 12.7 cm, respectively. The correlation coefficient was larger in the long and short groups than in the normal group. The intraclass correlation coefficient showed high agreement, and Pearson's correlation coefficient revealed correlation inspection as r = 0.702. Bland-Altman analysis indicated non-agreement, and the bias and upper and lower limits of agreement were 10.6 cm and -6.0 and 27.3 cm, respectively.

CONCLUSIONS

Short and long umbilical cord lengths are associated with perinatal mortality and morbidity. Prenatal measurement of umbilical cord length using MRI is feasible for daily clinical use to distinguish short or long umbilical cords. Further research is needed for more precise clinical application and technical reduction of overestimation errors.