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

Fetal Heart Rate Decelerations in Women with Sleep-Disordered Breathing

Emerging literature has shown that women with sleep-disordered breathing (SDB) have increased risk for gestational hypertension/preeclampsia and gestational diabetes. Case reports suggest an association between maternal apnea and fetal heart rate deceleration but data are lacking on how maternal sleep impacts fetal health. Since decelerations may be associated with adverse outcomes, we sought to determine whether fetal heart rate decelerations were associated with SDB. A cohort study of third trimester pregnant women with a singleton fetus was conducted. Participants underwent a home sleep test with continuous portable electronic fetal monitoring. SDB was defined as a respiratory disturbance index (RDI)≥10 events/hour. The temporality between a respiratory event and fetal heart rate decelerations was determined to be present if a deceleration occurred < 30 s after a respiratory event. Forty women were included with mean (±SD) age, BMI, and gestational age of 32.0±5.5 years, 37.1±8.0 kg/m², and 34.6±2.4 weeks respectively. Overall, n=23 (57.5%) women had SDB. Thirty-seven late decelerations were observed in 18 women; of these, 84% were temporally associated with a respiratory event. Nine of the 18 women (50%) had SDB. Ten prolonged decelerations were observed in 6 women of which nine (90%) were temporally associated with a respiratory event. Five of the six women (83%) had an RDI≥10. These initial data suggest that, in this population, the majority of both late and prolonged fetal heart rate decelerations occur with a maternal respiratory event. Since respiratory events are characteristic of maternal SDB, this raises the possibility that SDB may influence fetal well-being.

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

Objective

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

Methods

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

Results

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

Conclusions

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

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

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

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.

Umbilical Cord Abnormalities and Stillbirth

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

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

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

Can it really predict prior to delivery? A new ultrasonographic method for prediction of short and long umbilical cords in full-term pregnancy

Objective: This study aimed to ultrasonographically determine the presence of short and long umbilical cords in full-term, uncomplicated pregnancies before delivery.Methods: A total of 681 pregnant women aged between 18 and 35 years who had a single pregnancy and an intact amniotic membrane, and who were past the 37th week of gestation, were included. Umbilical cord lengths were ultrasonographically evaluated using a new method, and were compared with postnatal umbilical cord length.Results: The mean index values for short, normal, and long umbilical cords were 2.96, 5.36, and 6.98, respectively. The cut-off index value for a short umbilical cord was 3.75 and the sensitivity and specificity were calculated as 67 and 97%, respectively, for a value ≤3, and as 92 and 80%, respectively, for a value ≤4. The cut-off index value was 6.25 for a long umbilical cord and the sensitivity and specificity were calculated as 75 and 78%, respectively, for a value ≥6, and as 85 and 64%, respectively, for a value ≥6.5.Conclusions: Calculation of the umbilical cord length index is a new ultrasonographic method that can be easily used to predict short and long umbilical cords during routine amniotic fluid evaluation in full-term pregnancies.

Hemodynamic analysis of blood flow in umbilical artery using computational modeling

The umbilical cord is the crucial pathway for blood flow between the fetus and the placenta. Umbilical coiling and length have been separately linked to adverse clinical outcomes; however, the effects of variations of these parameters on umbilical arterial blood flow are not well understood. Using 3D computational model, we studied the individual and combined effects of umbilical coiling index, cord length and arterial diameter on umbilical artery hemodynamics. We found that specific combinations of umbilical coiling index, cord length and arterial diameter yielded pressure and flow drops incompatible with fetal life. Such models are useful as hypothesis-developing tools.