Neonatal outcome and mode of delivery in the presence of nuchal cord loops: implications on patient counselling and the mode of delivery

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.

Is There an Added Neonatal Risk in Vacuum-Assisted Deliveries with Nuchal Cord?

This retrospective cohort study assessed the association between nuchal cord and adverse outcomes during vacuum-assisted delivery (VAD). Women with singleton pregnancies, 34−41-weeks gestation, who underwent VAD, from 2014 to 2020 were included. The primary outcome was umbilical cord pH ≤ 7.1. Secondary outcomes were neonatal intensive care unit admission, Apgar scores, pH < 7.15, subgaleal hematoma, shoulder dystocia and third/fourth-degree perineal tear. Outcomes were compared between neonates with (1059/3754, 28.2%) or without (71.8%) nuchal cord after VAD. No difference in cord pH ≤ 7.1 was found between groups. The nuchal cord group had a lower rate of nulliparity (729 (68.8%) vs. 2004 (74.4%), p = 0.001) and higher maternal BMI (23.6 ± 4.3 vs. 23.1 ± 5, p = 0.017). Nuchal cord was associated with higher rates of induction (207 (19.5%) vs. 431 (16%), p = 0.009) and lower birthweights (3185 ± 413 vs. 3223 ± 436 g, p = 0.013). The main indication for VAD in 830 (80.7%) of the nuchal cord group was non-reassuring fetal heart rate (NRFHR) vs. 1989 (75.6%) controls (p = 0.004). The second stage was shorter in the nuchal cord group (128 ± 81 vs. 141 ± 80 min, p < 0.001). Multivariate regression found nulliparity, induction and birthweight as independent risk factors for nuchal cord VAD. Although induction and NRFHR rates were higher in VAD with nuchal cord, the rate of umbilical cord acidemia was not.

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.

The Relationship between Nuchal Cord and Adverse Obstetric and Neonatal Outcomes: Retrospective Cohort Study

Objective: The twisting of the umbilical cord around the fetal neck is a common phenomenon in the delivery room, and despite the lack of univocal evidence of its negative impact on perinatal events, it causes anxiety and stress in patients. The aim of the study was to assess the prevalence of nuchal cord and its impact on adverse obstetric and neonatal outcomes. Methods: We conducted a retrospective cohort study. All patients who gave birth in the clinic within one year (n = 1467) were included in the study group. We compared the prevalence of nuchal cord in distinct subgroups of patients. In the next stage, we estimated the chance of specific perinatal outcomes and compared the neonatal outcomes between groups with and without nuchal cord. Results: Nuchal cord was present in 24% of labors. It was twice as common among patients giving birth vaginally (32.14%) than among patients giving birth by a caesarean section (16.78%, p < 0.001). Nuchal cord was also more frequent in births with meconium-stained amniotic fluid (33.88% vs. 23.34%, p = 0.009). In the group of patients with nuchal cord, we observed a slight increase in the risk of a non-reassuring fetal heart rate trace (OR = 1.55, CI 95% 1.02−2.36) as an indication of the completion of labor by caesarean delivery. We did not note an increase in the risk of completing natural childbirth by vacuum extraction. In the group of nuchal cord patients, there was a higher chance of a serious or moderate neonatal condition in the first minute of life (Apgar 0−7 points) (OR = 2.00, 95% CI = 1.14−3.49). Conclusions: Nuchal cord increases the risk of a caesarean delivery due to a non-reassuring fetal heart rate trace. Nuchal cord increases the chance of a reduced Apgar score (0−7 points) in the first minute of life. The observed relationships do not translate to neonatal arterial blood gas testing.

No. 396-Fetal Health Surveillance: Intrapartum Consensus Guideline

OBJECTIVE

To present evidence and recommendations regarding use, classification, interpretation, response, and documentation of fetal surveillance in the intrapartum period and to provide information to help minimize the risk of birth asphyxia while maintaining the lowest possible rate of obstetrical intervention.

INTENDED USERS

Members of intrapartum care teams, including but not limited to obstetricians, family physicians, midwives and nurses, and their learners TARGET POPULATION: Intrapartum women OPTIONS: All methods of uterine activity assessment and fetal heart rate surveillance were considered in developing this document.

OUTCOMES

The impact, benefits, and risks of different methods of surveillance on the diverse maternal-fetal health conditions have been reviewed based on current evidence and expert opinion. No fetal surveillance method will provide 100% detection of fetal compromise; thus, all FHS methods are viewed as screening tests. As the evidence continues to evolve, caregivers from all disciplines are encouraged to attend evidence-based Canadian educational programs every 2 years.

EVIDENCE

Literature published between January 1976 and February 2019 was reviewed. Medline, the Cochrane Database, and international guidelines were used to search the literature for all studies on intrapartum fetal surveillance.

VALIDATION METHODS

The principal and contributing authors agreed to the content and recommendations. The Board of the Society of Obstetricians and Gynaecologists of Canada approved the final draft for publication. The level of evidence has been determined using the criteria and classifications of the Canadian Task Force on Preventive Health Care.

BENEFITS, HARM, AND COSTS

Consistent interdisciplinary use of the guideline, appropriate equipment, and trained professional staff enhances safe intrapartum care. Women and their support person(s) should be informed of the benefits and harms of different methods of fetal health surveillance.

RECOMMENDATIONS

CommunicationSupport During Active LabourPrinciples of Intrapartum Fetal SurveillanceSelecting the Method of Fetal Heart Rate Monitoring: Intermittent Auscultation or Electronic Fetal MonitoringPaper SpeedAdmission AssessmentsEpidural AnalgesiaIntermittent Auscultation in LabourElectronic Fetal Monitoring in LabourClassification of Intrapartum Fetal SurveillanceMaternal Heart RateFetal Health Surveillance Assessment in the Active Second Stage of LabourIntrauterine ResuscitationDigital Fetal Scalp StimulationFetal Scalp Blood SamplingUmbilical Cord Blood GasesDocumentationFetal Surveillance Technology Not RecommendedFetal Health Surveillance Education.

Umbilical cord length affects the efficacy of amnioinfusion for repetitive variable deceleration during labor

Objectives: Although amnioinfusion (AI) for repetitive variable deceleration has been reported to reduce the frequency of variable deceleration and cesarean section (CS) rate, CS is sometimes unavoidable even after therapeutic AI. The purpose of this study was to investigate prenatal factors related to the efficacy of therapeutic AI during labor.Methods: This retrospective study investigated 80 singleton pregnancies that underwent transcervical therapeutic AI for repetitive variable deceleration during labor. AI was performed with 500 mL of warmed saline through an intrauterine pressure catheter by gravity infusion. Prenatal factors related to emergency CS for fetal distress even after therapeutic AI were investigated.Results: Emergency CS was performed for 12 of the 80 cases due to fetal distress. Z-score for umbilical cord length was significantly smaller in the CS group (-0.68 SD) than in the vaginal delivery group (0.15 SD, p < .001). No CSs were performed in cases with Z-score for umbilical cord length >-0.05 SD. No significant differences between CS and vaginal delivery groups were seen in gestational age at delivery, cervical dilatation at AI, birth weight, Z-score of birth weight, incidence of the nuchal cord or incidence of abnormal umbilical cord insertion.Conclusions: Therapeutic AI for repetitive variable deceleration was considered useful, in many cases avoiding emergency CS. Short umbilical cord length (lower Z-score) was related to emergency CS after therapeutic AI for repetitive variable deceleration. Umbilical cord length may offer an important factor for assessing the risk of fetal distress that is difficult to avoid, if methods to accurately determine umbilical cord length can be developed.

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.

Does nuchal cord at birth increase the risk for cerebral palsy?

BACKGROUND

Nuchal cord is a common finding in pregnancy. It is unclear whether a nuchal cord at birth causes birth asphyxia and raises the risk for developing cerebral palsy of the offspring.

AIM

To evaluate the incidence of cerebral palsy in children born with and without nuchal cord.

STUDY DESIGN

A population-based cohort analysis including all singleton deliveries over >20 years at a single tertiary medical center was conducted. The incidence of cerebral palsy in children up to 18 years of age was evaluated. Kaplan-Meier survival curve was used to compare cumulative incidence between the groups, and a Cox proportional hazards model was used to control for confounders.

RESULTS

During the study period, 243,682 singleton deliveries met the inclusion criteria. Of them, 14.1% (n = 34,332) were diagnosed with nuchal cord at birth. Rates of cerebral palsy were comparable between the groups (0.1% vs. 0.1%, OR = 1.03, 95% CI 0.69-1.52, p = 0.89). The Kaplan-Meier survival curve demonstrated no significant differences in cumulative incidence of cerebral palsy for children born with or without nuchal cord (log rank p = 0.92, Fig. 1). The Cox proportional hazards model, controlled for preterm delivery, maternal age, diabetes and hypertensive disorders, showed no association between nuchal cord and cerebral palsy (adjusted HR = 1.06; 95% CI 0.71-1.57; p = 0.77).

CONCLUSION

In our population, nuchal cord at birth was not associated with higher risk for cerebral palsy.

Adverse pregnancy outcomes and multiple nuchal cord loops

PURPOSE

To evaluate the effects of nuchal cord and the number of loops during labor and delivery on delivery outcomes among women with singleton pregnancy who delivered vaginally.

METHODS

This retrospective cohort study included 42,798 women with singleton, vertex, and vaginal deliveries at 24-43 weeks of gestation. We analyzed delivery outcomes based on the number of nuchal cord loops.

RESULTS

A total of 42,798 deliveries met the inclusion criteria, of which, 3809 (8.9%) had nuchal cord with 1 loop at delivery, 1035 (2.42%) had 2 loops, and 258 (0.6%) had 3 loops. Nuchal cord with 3 loops compared to no nuchal cord has been associated with higher incidence of intrauterine fetal death (1.9%), Apgar scores less than 7 at 1 and 5 min (7.4%, 2.3%), and higher rate of operative vaginal deliveries (17.5%). Nuchal cord with 2 or 3 loops was associated with higher incidence of intrauterine growth restriction (10.2%, 11.6%).  In a multiple logistic regression model, nuchal cord with 3 loops was an independent risk factor for operative vaginal delivery and Apgar score less than 7 in 1 min.

CONCLUSIONS

In the case of vaginal delivery in the presence of nuchal cord, as the number of nuchal cord loops increased, so did the number of adverse delivery outcomes. While 3 loops were associated with higher incidence of intrauterine fetal death, intrauterine growth restriction, increased operative vaginal deliveries, and low Apgar scores, 1 loop was not associated with adverse perinatal outcomes.

Are increased fetal movements always reassuring?

Many studies have reported on the association of reduced fetal movements and stillbirth, but little is known about excessive fetal movements and adverse pregnancy outcome. First described in 1977, sudden excessive fetal movement was noted to reflect acute fetal distress and subsequent fetal demise. Subsequently, little was reported regarding this phenomenon until 2012. However, emerging data suggest that 10-30% of the women that subsequently suffer a stillbirth describe a single episode of excessive fetal movement prior to fetal demise. These episodes are poorly understood but may reflect fetal seizure activity secondary to fetal asphyxia, cord entanglement or an adverse intrauterine environment. At present, the challenge in managing women with excessive fetal movements is a timely assessment of the fetus to identify those women at risk of adverse fetal outcomes who may benefit from intervention.

Sonographic Assessment of the Umbilical Cord

The umbilical cord (UC) is a vital connection between fetus and placenta. It constitutes a stable connection to the fetomaternal interface, while allowing the fetal mobility that is of great importance for fetal development in general and fetal neuromotor development in particular. This combination of mechanical stability and flexibility is due to the architecture of the UC. There is however a range of umbilical cord complications that may be life threatening to the fetus and these too can be explained to a large extent by the cord's structural characteristics. This review article discusses clinically relevant aspects of UC ultrasound.

Effect of Umbilical Cord Entanglement and Position on Pregnancy Outcomes

Introduction. To investigate the effect of complex umbilical cord entanglement primarily around the trunk on pregnancy outcomes. Methods. We studied 6307 pregnant women with singleton pregnancies who underwent vaginal delivery of an infant at ≥37 weeks of gestation. Cases were classified into no cord, nuchal cord, and body cord groups and defined as cases without umbilical cord entanglement, one or more loops of the umbilical cord around the neck only, and umbilical cord around the trunk only, respectively. Pregnancy outcomes were compared among these three groups. Results. The no cord, nuchal cord, and body cord group included 4733, 1451, and 123 pregnancies, respectively. Although delivery mode was not significantly different among the three groups, 1-minute Apgar scores <7 and umbilical artery (UA) pH <7.10 were significantly more common in the umbilical cord entanglement groups than in the no cord group. In particular, the frequency of 5-minute Apgar scores <7 was significantly higher (P = 0.004), whereas that of UA pH <7.10 tended to be higher (P = 0.057) in the body cord group than in the nuchal cord group. Conclusion. Compared to nuchal cord, umbilical cord entanglement around the trunk was associated with a higher risk of low Apgar scores and low UA pH.