Risk factors for nuchal cord entanglement at delivery

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.

Adverse outcomes of nonnuchal umbilical cord entanglement

OBJECTIVE

To evaluate perinatal effects of umbilical cord entanglement (UCE) of different body parts.

METHODS

The database of a tertiary medical center was retrospectively searched for women who gave birth to a liveborn singleton newborn in 2014-2018. Those diagnosed postpartum with UCE were matched 1:10 with women who were not and compared for adverse obstetric and neonatal outcomes, overall and by site of entanglement.

RESULTS

A total of 14 299 women were evaluated, of whom 1243 were diagnosed with UCE: 78.7% neck, 26% trunk, 6.7% limb. UCE was associated with lower birth weight percentile and higher rate of small for gestational age, but findings were significant only for neck and trunk UCE. On multivariate regression analysis adjusted for maternal age, parity, gestational age at birth, and history of cesarean delivery, UCE was an independent risk factor for nonreassuring fetal heart rate, labor induction, operative vaginal delivery, cesarean delivery, and meconium-stained amniotic fluid, but not for lower absolute birth weight/birth weight percentile, small for gestational age, low 1-min Apgar score, or neonatal asphyxia.

CONCLUSION

While fetuses with UCE might be more compromised during labor, they apparently recover shortly after birth. The impact on perinatal outcomes was similar for UCE of the neck and trunk and lower for UCE of the limb.

Caesarean delivery of a breech singleton with eight loops of nuchal cord

Nuchal cord accidents comprise a third of stillbirths in the third trimester. These are often due to higher order nuchal cords, with more than three loops. In this report, we discuss a case of a gestation complicated by a nuchal cord with eight loops and severe fetal growth restriction, requiring expedited delivery due to non-reassuring fetal heart tones. Our case demonstrates the value of high-quality ultrasound in detecting complex nuchal cords, as well as highlighting the potentially dynamic and unstable fetal status in an affected gestation. Antenatal knowledge of nuchal cord in the setting of non-reassuring fetal status can help guide patient counselling and assist with identifying possible aetiologies. Finally, our case demonstrates that close monitoring and early intervention can prevent potentially catastrophic outcomes.

The effect of nuchal umbilical cord on fetal cardiac and cerebral circulation-cross-sectional study

OBJECTIVES

The subject of our analysis is the influence of umbilical cord collision around the fetal neck on the fetal heart function and cerebral circulation.

METHODS

Our study was carried out on a group of 115 fetuses from single pregnancies with physiological course, during the 15th to 40th week of pregnancy. In our analysis, we examined the following parameters: Tei index for right ventricle, Tei index for left ventricle with Tei index components: isovolumetric contraction time, isovolumetric relaxation time, ejection time and cardiothoracic area ratio, middle cerebral artery peak systolic velocity (PS MCA), middle cerebral artery pulsatility index (PI MCA). Gestational age in our study was: 28+2±34. The study group of patients with fetal umbilical cord around neck group (fUCAN) included 38 fetuses (20 males, 18 females). The control group of patients with no fetal umbilical cord around neck group (NfUCAN) included 77 fetuses (43 males, 34 females).

RESULTS

In our study, we found no significant differences in the values obtained: Tei LV in fUCAN: 0.5±0.1 vs. in NfUCAN: 0.5±0.1; p=0.42), Tei RV in fUCAN: 0.5±0.2 vs. in NfUCAN: 0.4±0.1; (p=0.2). Tricuspid valve regurgitation-TR was observed with the following frequency: fUCAN: 7/38, 18% vs. NfUCAN: 13/77, 17%; p=0.8. MCA PS in study fUCAN group was significantly higher than in NfUCAN (40.2±11.5 vs. 32.5±9.5; p=0.003), although other hemodynamic and clinical variables did not differ between the study and control groups.

CONCLUSIONS

The fetal nuchal umbilical cord collision did not affect the fetal heart function expressed as Tei index, at the time of fetal heart examination (at mean gestational age 29+4 weeks). The fUCAN group presented elevated PS MCA, which was not related to other hemodynamic and clinical variables between the study and control groups.

Current Perspectives of Prenatal Sonographic Diagnosis and Clinical Management Challenges of Complex Umbilical Cord Entanglement

Diagnosis of potential umbilical cord compromise, namely, true knots of the umbilical cord and nuchal cords has been enabled with increasing accuracy with current enhanced prenatal sonography. Often an incidental finding at delivery, the incidence of true knots of the umbilical cord has been estimated at between 0.04% and 3% of deliveries. This condition has been reported to account for a 4 to 10-fold increase of stillbirth and perinatal morbidity of 11% of cases. Nuchal cords, commonly observed at the delivery of uncompromised, non-hypoxic non-acidotic newborns occur more frequently with single nuchal cords noted in between 20% and 35% of all deliveries at term. Multiple nuchal cords are considerably less frequent, with decreasing frequencies inverse to the number of nuchal cord loops. While clearly single (and likely double) nuchal cords are almost uniformly associated with favorable neonatal outcomes, emerging data suggest that cases of ≥3 loops of nuchal cords are more likely to be associated with an increased risk of adverse perinatal outcome (either stillbirth or compromised neonatal condition at delivery). We define cases of a true knot of the umbilical cord, cases of ≥3 loops of nuchal cords, any combination of a true knot and nuchal cord, or any umbilical cord entanglement (nuchal or true knot) in the presence of a single umbilical artery, in singleton gestations as complex umbilical cord entanglement. Two concurrent developments, the increase in accuracy of prenatal sonographic diagnosis of complex umbilical cord entanglement and recent data confirming fatal compromise of the umbilical circulation in approximately 20% of cases of stillbirth, suggest that establishing governing body guidelines for reporting of potential umbilical cord compromise, and recommendation of consideration for early-term delivery of select cases, may be warranted. This commentary will address current perspectives of prenatal diagnosis and clinical management challenges of complex umbilical cord entanglement.

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.

Current Perspectives of Prenatal Sonographic Diagnosis and Clinical Management Challenges of Nuchal Cord(s)

Umbilical cord accidents preceding labor are uncommon. In contrast, nuchal cords are a very common finding at delivery, with reported incidences of a single nuchal cord of approximately between 20% and 35% of all singleton deliveries at term. Multiple loops occur less frequently, with reported incidence rates inverse to the number of nuchal cords involved. Rare cases of up to 10 loops of nuchal cord have been reported. While true knots of the umbilical cord have been associated with a 4–10-fold increased risk of stillbirth, nuchal cord(s) are most often noted at delivery of non-hypoxic non-acidotic newborns, without any evidence of subsequent adverse neonatal outcome. Prior to ultrasound, nuchal cords were suspected clinically following subtle (spontaneous or evoked) electronic fetal heart rate changes. Prenatal sonographic diagnosis, initially limited to real-time gray-scale ultrasound, currently entails additional sonographic modalities, including color Doppler, power Doppler, and three-dimensional sonography, which have enabled increasingly more accurate prenatal sonographic diagnoses of nuchal cord(s). In contrast to true knots of the umbilical cord (which are often missed at sonography, reflecting the inability to visualize the entire umbilical cord, and hence are often incidental findings at delivery), nuchal cord(s), reflecting their well-defined and sonographically accessible anatomical location (the fetal neck), lend themselves with relative ease to prenatal sonographic diagnosis, with increasingly high sensitivity and specificity rates. While current literature supports that single (and possibly double) nuchal cords are not associated with increased adverse perinatal outcome, emerging literature suggests that cases of ≥3 loops of nuchal cords or in the presence of a coexisting true knot of the umbilicus may be associated with an increased risk of stillbirth or compromised neonatal status at delivery. This commentary will address current perspectives of prenatal sonographic diagnosis and clinical management challenges associated with nuchal cord(s) in singleton pregnancies.

Predictors of chest drainage of pneumothorax in neonates

This is a retrospective, single-center observational study to explore the predictors of chest drainage for neonatal pneumothorax. A total of 183 neonates (age ≤28 days) who presented to the Children's Hospital of Soochow University between January 1, 2015 and December 31, 2018 for pneumothorax or developed pneumothorax during a hospital stay were included. Demographic data, clinical presentation, and imaging characteristics of neonatal pneumothorax were collected and analyzed. We used univariate and multivariate logistic regression analyses to determine significant predictors of chest drainage of pneumothorax in neonates. Pneumothorax occurred within 24 h after birth in 131 (71.6%) cases, between 24 and 48 h after birth in 41 (22.4%) cases, and 48 h after birth in 11 (6.0%) cases. Univariate and multivariate logistic regression analyses revealed that lung collapse ≥1/3 on initial chest X-ray (OR 4.99, 95%CI 2.25-11.07), chest retractions (OR 8.12, 95%CI 2.88-22.89), cyanosis (OR 2.25, 95%CI 1.08-4.66), and frothing from mouth (OR 2.49, 95%CI 1.12-5.49) (P<0.05 for all) were significant predictors of the need for chest drainage due to pneumothorax. In conclusion, the thorough evaluation of the above predictive factors can guide treatment and improve patient outcome.

Antenatal course and perinatal outcome after ultrasound detection of triple nuchal cord: a case series

OBJECTIVE

To determine the antenatal course and perinatal outcome of pregnancies in which a triple nuchal cord was detected prenatally by ultrasound.

METHODS

Singleton pregnancies presenting for ultrasound evaluation after 24 weeks of gestation were routinely screened for the presence of nuchal cord loops using two-dimensional and color-Doppler ultrasound. Fetuses with more than two nuchal cord loops were identified from our fetal medicine database and their ultrasound reports and medical records were reviewed.

RESULTS

During the study period from July 2014 to February 2019, 10 singleton fetuses with triple nuchal cord were identified, for a prevalence of 1 in 506 or 0.2%. No cases of more than three nuchal cord loops were detected. No predisposing factors were identified. Cases detected after 36 weeks (n = 4) delivered by cesarean section after 37 weeks and the diagnosis of triple nuchal cord was confirmed in all of them. Cases detected before 36 weeks (n = 6) underwent fetal surveillance. Among these cases, the umbilical cord unraveled itself from around the fetal neck in at least one loop in 83% of these cases. Overall, eight (80%) of the neonates were delivered by cesarean section for different reasons; in only two, the sole indication for cesarean delivery was the presence of the triple nuchal cord. All the infants had a good perinatal outcome, although one newborn infant was small for gestational age.

CONCLUSIONS

Ultrasound detection of triple nuchal cord during late pregnancy was associated with good perinatal outcomes. However, this prenatal finding was also associated with a high rate of cesarean section. In preterm pregnancies, multiple loops will reduce spontaneously in the majority of cases, so expectant management is indicated. In term pregnancies, the decision regarding the optimal timing and mode of delivery should be discussed with the parents taking into account the individual clinical scenarios.

Outcome of pregnancies with marginal umbilical cord insertion

PURPOSE

To evaluate the outcome of labor in cases of marginal umbilical cord insertions.

MATERIAL AND METHODS

This case-control study was carried out between December 1st, 2017 and April 30th, 2018. All singletons with marginal cord insertion (MCI) and three new-borns without MCI were recruited. The main variables studied included gestational age at delivery, occurrence of preeclampsia, intrapartum haemorrhage, mode of delivery, cord insertion, cord length, birth and placenta weights, presence of nuchal cord, Apgar score and admission of the new-born into the neonatal intensive care unit (NICU). Data from both groups were compared. Fisher exact test, t-test and logistic regression were used for comparison. p < .05 was considered statistically significant.

RESULTS

Our prevalence of MCI was 7.2% (85/1181). MCI was significantly associated with pre-eclampsia (aOR 2.94, 95%CI 1.14-7.59), placenta abruption (OR 33.68, 95%CI 9.80-115.76), nuchal cord entanglement (aOR 3.07, 95%CI 1.69-5.59), low birth weight (aOR 3.15, 95%CI 1.05-9.45) and transfer of the newborn to the NICU (OR 4.72, 95%CI 2.46-9.04).

CONCLUSIONS

MCI is associated with increased maternal, fetal and neonatal adverse morbidities. Therefore, pregnancy with MCI should be well followed up. Moreover, the delivery should be conducted in settings where rapid intensive neonatal care can be offered.