Evaluation of fetal serum thiol/disulphide homeostasis in deliveries complicated by nuchal cord.

Aim: To investigate the serum thiol/disulphide homeostasis in deliveries complicated by nuchal cord (NC) and to compare the results with healthy deliveries (without NC). Methods: This prospective controlled study included 48 pregnant women complicated by NC and 48 similar gestational aged healthy pregnant women during labor. Fetal umbilical cord serum samples were collected during labor and the thiol/disulphide homeostasis was measured by using an automated assay method. The patients were followed up until end of the delivery and perinatal outcomes were recorded. Results: Fetal umbilical cord native thiol, total thiol, and disulphide levels as well as disulphide/native thiol and disulphide/total thiol ratios are impaired in labor with the presence of NC. There were no statistically significant differences in terms of maternal and gestational age at delivery and maternal number of gravida and parity, fetal gender, fifth Apgar scores <7, mode of delivery and fetal birth weight between groups. The group of patients with NC had higher emergency C/S numbers indicated for fetal distress and lower first Apgar scores <7. There were no neonatal intensive care unit admissions among these babies. Conclusions: Maternal serum thiol/disulphide homeostasis reflect transient effects of NC during labor regardless of labor type. Vaginal delivery can be safely and successfully performed in pregnancies complicated with NC.

The impact of nuchal cord on umbilical cord blood gas analysis and ischaemia-modified albumin levels in elective C-section.

This study was designed to evaluate umbilical cord ischaemia-modified albumin (IMA) levels and the cord blood gas parameters of foetuses with or without nuchal cords, at the time of elective C-section. The cross-sectional study population consisted of the patients who were admitted to the Tertiary Care Center between February and June 2015. Women with uncomplicated single term gestations between 37 and 40 completed weeks and scheduled for elective C-sections were included in the study. Fifty cases with a nuchal cord and 50 cases without a nuchal cord were recruited. Nuchal cord blood gas analysis and the IMA levels were evaluated. The IMA levels in umbilical artery of foetuses both in the study and control groups were similar (0.714 ± 0.150 vs. 0.689 ± 0.107 ABSU, p = .340, respectively). The umbilical artery pH values of the study group were significantly lower than that in the control group (7.31 ± 0.04 vs. 7.32 ± 0.03, p = .042; respectively). The results of the current study indicate that the nuchal cord has an impact on the foetal cord blood gas parameters to some extent before the initiation of labour. Fortunately, this impact does not end up with foetal tissue ischaemia, as confirmed by the IMA levels. Impact statement What is already known on this subject? The impact of nuchal cord on perinatal outcomes has been the subject of research for many years. Although the accumulated data has pointed out some unfavourable perinatal effects, the heterogeneity of the study groups both including a vaginal delivery and C-section and the inability to adjust the interfering factors ended up with some controversies. This is why there is not much known about the effects of the nuchal cord in women who are not in the labour process. What do the results of this study add? The current study aimed to exclude the interfering effects such as the active stage of labour. In this study, elective caesarean sections were selected as the study population to evaluate the effects of the nuchal cord on cord blood gas parameters and the IMA values. pH analysis in cord blood is used to detect hypoxia and the IMA is a new ischaemia marker. The results revealed that the in utero nuchal cord is associated with a significantly higher pCO2 and lower pH values and similar IMA values. What are the implications of these findings for clinical practice and/or further research? The final outcome supports that the nuchal cord causes alterations in cord blood gas analysis but this does not reach critical levels. Therefore, the results show that there is no need to change clinical practice when the nuchal cord is detected by ultrasound in a term gestation.

IL-6 and TNFalpha across the umbilical circulation in term pregnancies: relationship with labour events.

OBJECTIVE: We have determined venous and arterial cord blood levels for IL-6 and TNFalpha at the time of delivery to assess gestational tissue versus fetal sources in labouring and non-labouring patients at term, and the relationship to labour events. METHODS: Fifty-five patients were studied (elective cesarean section n=24, and labouring n=31) with blood sampling from a clamped segment of cord after delivery of the fetus and from the cord at its insertion into the placenta after delivery of the placenta, with subsequent measurement of blood gases, pH, IL-6 and TNFalpha. RESULTS: Umbilical cord levels for IL-6 were increased by 4 fold in low risk labouring patients, and a further 6 fold when showing histologic chorioamnionitis, but with no evident effect of nuchal cord with 'variable' fetal heart rate decelerations, fetal acidemia, nor of labour duration. IL-6 levels from the cord at its insertion into the placenta were generally higher than those from the respective umbilical levels indicating that placental release of IL-6 into cord blood must be occurring. However, a consistent venoarterial difference for IL-6 and thereby a net flux from the placenta could not be demonstrated. TNFalpha levels for both patient groups were uniformly low for all of the cord measurements with no significant differences noted. CONCLUSION: Umbilical cord levels for IL-6 are increased in low risk labouring patients at term in the absence of evident infection which likely involves both gestational tissue and fetal contributions. Cord levels for IL-6 are further increased in low risk labouring patients showing histologic chorioamnionitis which might then contribute to newborn morbidity in these pregnancies.

Lipid peroxidation in nuchal cord cases: implication for fetal distress.

OBJECTIVE: To examine whether nuchal cord affects fetal lipid peroxidation and cord arterial blood gases, and thus to determine whether lipid peroxidation can show intrapartum distress. METHODS: Pregnant women giving birth to a baby with nuchal cord (n = 32) formed the study group and others without this condition made up the control group (n = 36). The maternal malondialdehyde levels (MDA) before and after delivery as well as fetal umbilical cord MDA and arterial blood gases were measured in both the groups. RESULTS: Mean cord MDA level was higher in the study group (p < 0.02) and was significantly higher than maternal MDA level after birth within the same group (p = 0.007). Cord blood gases as well as neonatal and labour characteristics showed no difference, except for variable decelerations, which were 2.2 times more common in the study group. Correlations between maternal MDA levels before and after delivery, umbilical cord MDA and arterial blood gases were non-significant in the nuchal cord group. CONCLUSIONS: During delivery, nuchal cord increases lipid peroxidation without causing significant fetal acidemia. Level of lipid peroxidation may be a more sensitive indicator of intrapartum distress than results of acid-base studies.

Perinatal features and umbilical cord blood gases in newborns complicated with nuchal cord.

Presence of nuchal cord (NC) is associated with transient decrease of umbilical cord blood flow. However, the exact perinatal effect of presence of NC in a newborn is still under debate. The aim of this study was to evaluate the perinatal complications and umbilical cord blood gases of deliveries complicated with NC and summarize the associated literature. Gestational age-matched term singleton pregnancies complicated with NC (n=160) were compared with neonates without NC (n=160). Patients' files and Labor and Delivery Unit database were used to extract maternal age, gestational age, presence of NC, number of nuchal loops around fetal neck, intrapartum complications and umbilical cord blood gases. pH, pO2, pCO2, HCO3-, O2 saturation, and base excess were determined in all patients. Mean maternal age, mean gestational age, and birth weight were not significantly different between the two groups (p > 0.05). Occurrence of oligohydramnios, intrauterine growth retardation (IUGR), intrapartum abnormalities and Apgar scores < 7 at 1 minute were not significantly different between the groups (p>0.05). However, umbilical cord blood pH (7.32 vs. 7.30, p = 0.048), pO2 (37.4 +/- 18.1 vs. 31.7 +/- 14.4, p = 0.01) and O2 saturation (57.4 +/- 21.8 vs. 48.3 +/- 20.4, p = 0.005) were significantly lower in the NC group compared with the controls. Furthermore, the number of Apgar scores < 7 at 1 minute was significantly higher in neonates with multiple NC (28.1% vs. 9.2%, p = 0.007), and intrapartum abnormalities were more frequently seen in newborns with multiple NC (31.3% vs.15.6%, p = 0.04). The results of this study suggest that presence of single NC may negatively affect the umbilical cord blood gases without significant perinatal complications. However, multiple NC may also increase the development of intrapartum complications and lower Apgar scores. Perinatal effects of NC should be investigated with a large prospective study.