|Year : 2019 | Volume
| Issue : 2 | Page : 448-452
Effect of umbilical cord entanglement on pregnancy outcomes Menoufia Medical Journal
Zakaria F Sanad1, Tarek M Sayyed1, Hesham A Ammar1, Mohamed F El-Kherbawy2
1 Department of Obstetrics and Gynecology, Faculty of Medicine, Menoufia University, Menoufia, Egypt
2 Department of Obstetrics and Gynecology, Al-Monira General Hospital, Cairo, Egypt
|Date of Submission||04-Oct-2017|
|Date of Acceptance||05-Nov-2017|
|Date of Web Publication||25-Jun-2019|
Mohamed F El-Kherbawy
Gamal Abd El Nasr Street, Shebeen El Kom, Menoufia
Source of Support: None, Conflict of Interest: None
This work aimed to study the effect of umbilical cord entanglement on the mode of delivery. In addition, this study aimed to evaluate the sensitivity of ultrasound with Doppler for the detection of nuchal entanglement of the umbilical cord.
The umbilical cord is a narrow tube-like structure that connects the developing baby to the placenta. Most of the nuchal cords diagnosed in early pregnancy become spontaneously uncoiled.
Materials and methods
This cohort study included 300 pregnant laboring women with singleton pregnancies more than 37 weeks. This study was carried out from January 2016 to February 2017 in the Obstetrics and Gynecology Department of El Moniera General Hospital, Cairo. A transabdominal ultrasound scan was performed using gray-scale and color Doppler imaging immediately to screen for any cord loops around the fetal neck or around the trunk. Cases were classified into either no cord entanglement or cord entanglement groups. Pregnancy outcomes were compared among these groups.
No cord and cord entanglement groups included 226 and 74 pregnancies, respectively. The mode of delivery was not significantly different among the study groups (P = 0.231). However, the mean of 1 min Apgar scores was significantly lower in the umbilical cord entanglement group than in the 'no cord' group (P = 0.001). Both the sensitivity and the specificity of ultrasound with color Doppler were 95 and 99%, respectively.
There was no effect of umbilical cord entanglement on the mode of delivery. Ultrasound with Doppler is sensitive for the detection of nuchal entanglement of the umbilical cord.
Keywords: entanglement, nuchal, pregnancy outcome, umbilical cord
|How to cite this article:|
Sanad ZF, Sayyed TM, Ammar HA, El-Kherbawy MF. Effect of umbilical cord entanglement on pregnancy outcomes Menoufia Medical Journal. Menoufia Med J 2019;32:448-52
|How to cite this URL:|
Sanad ZF, Sayyed TM, Ammar HA, El-Kherbawy MF. Effect of umbilical cord entanglement on pregnancy outcomes Menoufia Medical Journal. Menoufia Med J [serial online] 2019 [cited 2020 Feb 27];32:448-52. Available from: http://www.mmj.eg.net/text.asp?2019/32/2/448/260910
| Introduction|| |
The incidence of umbilical cord entanglement in delivery cases ranges from 14.7 to 33.7. It is believed that it may increase the risk of nonreassuring fetal heart rate status and may prolong labor. The prevalence of the nuchal cord has been reported to range between 6 and 37% at delivery. It is identified when the umbilical cord passes 360° around the fetal neck. In one study, nuchal cord showed a single loop in 20.6%, a double loop in 2.5%, and even a triple loop in 0.2% of 1007 infants at delivery. A loop of the umbilical cord around the fetal neck (nuchal cord) is a common finding at delivery. There are controverse that prenatal ultrasound examination for identifying the presence of nuchal cords would alter antepartum and intrapartum care. Prenatal ultrasound examination for identifying the presence of nuchal cords would alter antepartum and intrapartum care are controversial. Single or multiple entanglements around the fetal neck can occur as a nuchal cord that may be loose or mildly to severely constricting. A Divot sign is identified when there is compression of the skin of the fetal neck, leading to disruption of the smooth contour. This sign has been used to define a tight nuchal cord. Potential complications and birth injuries resulting from a nuchal cord are increased rate of intrapartum fetal heart rate abnormalities, hypoxic ischemic encephalopathy/birth asphyxia, fetal death, meconium aspiration syndrome, umbilical cord prolapse, vasa previa, and neurodevelopmental abnormalities. A specific intervention is required for resolution of these complications to tackle the underlying cause and to determine the timing of delivery with the aim of avoiding prolonged fetal hypoxia/acidosis as well as unnecessary obstetric intervention. Therefore, cardiotocography is very important to determine fetal hypoxia with high sensitivity, but with a limited specificity in predicting fetal acidosis. Antenatally, one of the useful means for the identification of a nuchal cord is an obstetric ultrasound. It is diagnosed when at least three quarters of the fetal neck are visualized as being encircled at both longitudinal and transverse views of the fetal neck. The sensitivity is increased by also performing Doppler imaging, especially in suspicious cases. The sensitivity of gray-scale imaging for the diagnosis of a nuchal cord at term is 70%, whereas this figure increases to a range of 83–97% when color Doppler is used. Theoretically, an entangled cord may hinder the progress of the fetal head toward the outlet. Furthermore, it may lead to nonreassuring fetal heart patterns. During labor induction by prostaglandins, the increased uterine activity may lead to increased prevalence of nuchal cord and in turn an increased cesarean delivery rate. Although the nuchal cord is often considered to be responsible for most of the problems encountered during delivery, the actual significance of a nuchal cord in intrapartum events and perinatal outcome is controversial. The aim of this work was to study the effect of umbilical cord entanglement on the mode of delivery. In addition, the aim was to evaluate the sensitivity of ultrasound with Doppler for the detection of nuchal entanglement of the umbilical cord.
| Materials and Methods|| |
This cohort study was carried out from January 2016 to February 2017 in the Obstetrics and Gynecology Department of El Moniera General Hospital. The study cohort included 300 pregnant women admitted to the hospital because of early spontaneous labor. The participants signed an informed consent after receiving full information on the study design. An approval from the hospital institutional review board was obtained before commencing the study. Inclusion criteria included women with singleton pregnancy with gestational age between 37 and 41 completed weeks who were in spontaneous labor. Patients with multiple pregnancy, medical disorders during pregnancy, oligohydraminos, women who had delivered a newborn with congenital anomalies, fetal malpresentation, and patients with a history of previous hysterotomy (uterine scar) were excluded from this study. All study participants were assessed by a comprehensive assessment of history, physical examination, and abdominal obstetric ultrasound evaluation to verify inclusion criteria and to exclude women with any of the previously mentioned exclusion criteria. A transabdominal ultrasound scan (GE Healthcare Logiq P3, Machine General Electric Company, Wauwatosa, USA) was performed using gray-scale and color Doppler imaging immediately to screen for any cord loops around the fetal neck or around the trunk with a 3.5 MHz abdominal probe. All the ultrasound scans were performed by the same operator and both the women and clinicians were blinded to the results. The presence of the cord was sought in the transverse and sagittal plane of the neck and a nuchal cord was diagnosed if the cord was visualized lying around at least three of the four sides of the neck. The presence of a nuchal cord on scan was classified as present, not present, or uncertain (when a clear view of all sides of the neck could not be obtained). Clinical evaluation of the participants in labor was carried out by an experienced obstetrician. Continuous monitoring of the fetal heart rate was performed throughout labor by cardiotocography and partographic follow-up was performed for all cases. Cesarean section (CS) was performed according to obstetric indications. After delivery, the following variables were derived for each case: the presence of cord entanglement and the number of loops around the fetal neck or around the trunk at delivery, Apgar scores at 1 and 5 min, neonatal weight, and the need for admission to the neonatal ICU. Two study groups were developed retrospectively: a control group with no cord entanglement and a cord entanglement group (study group) after postdelivery confirmation of the location of the umbilical cord. In this study, it was assumed that the presence of nuchal cord entanglement would increase the incidence of CS by 13%. Accordingly, at an α error of 0.05 and a study power of 80%, a total sample size of 300 woman was required.
Results were collected, tabulated, and statistically analyzed by an IBM compatible personal computer using the SPSS statistical package version 20 (SPSS Inc., Chicago, Illinois, USA) released 2011. IBM SPSS statistics for windows, version 20.0 (IBM Corp., Armonk, New York, USA). Student's t-test was used for comparison between two means of normally distributed data, whereas Mann–Whitney's test was used for non-normally distributed data. The χ2-test was used for qualitative data.
| Results|| |
This study included 300 spontaneously laboring women, mean age 25.89 ± 4.71 years. Primigravidity constituted 23% of total participants versus multiparous women were 77% of total participants. Postdelivery cord entanglement was found in 74 (24.6%) cases, whereas no cord entanglement was found in 226 cases. The parity, women's age, and gestational age did not differ significantly in the study groups (P = 0.755, 0.637, and 0.273). The incidence of nuchal cord entanglement was 87.8% among all cases of cord entanglement [Table 1] and [Table 2]. The intrapartum ultrasound with Doppler could detect 70 out of 74 cases of cord entanglement with a sensitivity of 94.5% meanwhile it could exclude 223 of cord entanglement out of 226 cases with a specificity of 98.6%, yielding an accuracy of 98% [Table 3]. The intrapartum data of the two groups (no cord and cord entanglement) including the Bishop score, duration of first stage, duration of second stage, and abnormal fetal heart rate patterns did not show a statistically significant difference [Table 4]. The rate of CSs was 5.4% among the participants in the cord entanglement group versus 2.2% among parturients of the noncord entanglement group, with no statistically significant difference (P = 0.231). There were no cases of operative vaginal deliveries in this study. The mean for first minute Apgar scores of newborns with cord entanglement (5.9 ± 1.08) was lower than its counterpart in newborns without cord entanglement (8.43 ± 0.81), with a statistically significant significance (P = 0.001). Moreover, the mean umbilical cord length of the cord entanglement group was longer than cases in the no cord entanglement group (P = 0.031). However, the mean values of other parameters such as Apgar scores at 5 min, birth weight, and need for neonatal intensive care admission did not show a statistically significant difference (P = 0.06) [Table 5].
|Table 2: Number and percentage distribution of different sites of cord entanglement at delivery|
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|Table 4: Intrapartum clinical features of participants in the study groups|
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| Discussion|| |
It is still a matter of debate in the literature whether nuchal cord is related to increased fetal morbidity and mortality, albeit its occurrence is not uncommon. As a consequence of acute cord compression during labor, fetal bradycardia occurs, which, if prolonged, can lead to abnormal fetal heart patterns and alteration of fetal metabolic status. Different factors related to the mother, fetus, cord, placenta, and labor have been associated with the presence of a nuchal cord. Excessive fetal movement and a long umbilical cord may lead to the formation of a nuchal cord. As the baby's gestational age increases, so does the likelihood of a nuchal cord. One study found that at 20 weeks gestation, the presence of a nuchal cord was about 5.8% of cases while 29% of cases was found at 42 weeks gestation of delivieries. Although about 25–50% of nuchal cords formed at any one time will resolve before delivery, the primary misconception is that the child is being strangulated or suffocated by this cord around the neck. As the fetus cannot breathe within the womb, the mother has to deliver all the oxygen and clear away all of the carbon dioxide of the infant. This exchange is accomplished in the placenta. Umbilical vessels within the umbilical cord are essential for fetal gas exchange that takes the place of breathing while the fetus is inside the womb. In the present study, the presence of umbilical cord entanglement did not affect the mode of delivery and the incidences of cesarean delivery in our study groups did not differ at a statistically significant level. This finding was in agreement with the majority of previous studies, such as Sheiner et al., Joshi et al., Ogueh et al., Ghi et al., and Kobayashi et al.. The current study showed a high sensitivity and specificity of the ultrasound with color Doppler in the diagnosis of cord entanglement: 94.6 and 98.6%, respectively. This was comparable with a color Doppler ultrasound sensitivity range of 83–97% according to other reports,. A study by Peregrine et al. had shown lower ultrasound sensitivity of 60 and 37%, respectively, in diagnosing a nuchal cord when there was more than one loop versus only one loop. The total incidence of cord entanglement in our study was 24.7%. Lower figures of cord entanglement were reported by Sheiner et al., Joshi et al., and Singh and Sidhu: 14.7, 19.7, and 18.6%, respectively. This might be because of the noninclusion of other varieties of abnormal cord placement besides nuchal position of the cord. In terms of the neonatal outcomes, the neonates in the cord entanglement group had a significantly lower mean Apgar score at the first minute (<7). This was in agreement with studies by Sheiner et al. and Shrestha and Singh. However, in a study by Peregrine et al., the presence of a nuchal cord did not significantly increase the risk of Apgar score less than 7 in the first minute. Despite a statistically significant difference in the mean first minute Apgar scores in our study groups, there were comparable fifth minute mean Apgar scores, with no statistically significant difference (>7), and this was in agreement with Shrestha and Singh. In contrast to these findings, Sheiner et al. reported that their mean fifth minute Apgar score less than 7 was significantly lower in newborns without a nuchal cord and the perinatal mortality rate was also significantly higher in the same group (without nuchal cord). In the study groups, there was no statistically significant difference in the number of neonates who required neonatal intensive care admission. This finding was consistent with a study by Shrestha and Singh. Of the current study limitations is nonmeasuring the umbilical cord for the newborns which might have disclosed hidden significant differences in the newborns of the study groups. A second limitation is nonstratification of the degree of nuchal cord according to the number of coils around the newborn's neck. Moreover, cases with multiple umbilical cord entanglements involving multiple parts of the body, such as entanglement around both the neck and the upper/lower limbs, were not excluded.
| Conclusion|| |
There is no effect of umbilical cord entanglement on the mode of delivery. In addition, the sensitivity of two dimensional ultrasound with Doppler for the detection of nuchal entanglement of umbilical cord is about 95%; thus, the ultrasound can be used for the evaluation of cord entanglement. According to our study, looking for a possibility of a nuchal cord during a routine antenatal ultrasound scan is not a sine qua nonrequirement of that procedure. However, if it is suspected during an ultrasound scan, it should be verified by Doppler ultrasound. If continuous intrapartum electronic fetal heart rate monitoring is offered in such cases, it cannot be declined but it is not mandatory.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]