Department of Obstetrics and Gynaecology, University College of Medical Sciences and GTB Hospital, Dilshad Garden, New Delhi, India.
Arch Gynecol Obstet. 2014 Apr;289(4):795-801. doi: 10.1007/s00404-013-3072-9. Epub 2013 Nov 5.
Birth asphyxia leading to acidosis comprises 20-60 % of perinatal mortality. Nuchal cord (NC) is one of the possible causes of birth asphyxia. Majority of fetuses who are antenatally detected to have nuchal cord are able to achieve successful vaginal birth. The purpose of this study was to analyze the effect of nuchal cord on fetal acid base status and perinatal outcome in vaginal deliveries.
150 parturients were equally divided into three groups after vaginal delivery based on no NC, single and multiple loops. Umbilical cord arterial blood was analyzed for biochemical markers i.e. pH, PO2, SPO2, PCO2, HCO3 (-), standard base excess and lactate for acidosis. Labor complications like abnormal FHR, meconium-stained liquor, prolonged second stage, instrumental vaginal delivery, third stage complications were compared. In neonates, birth weight, Apgar score ≤7 at 5 min, NICU admission and other morbidity and mortality during hospital stay were compared among groups using suitable statistical tests. Above parameters were also compared between tight and loose loops.
Nuchal cord groups had significantly higher frequency of labor complications than no NC group, especially tight loops. Neonates with NC had significantly higher frequency of meconium-stained liquor, Apgar score ≤7 at 5 min, deranged biochemical markers, NICU transfer. However, none of the neonate had pH in acidosis range and majority were discharged in healthy condition.
Patients with NC are likely to have uneventful labor and delivery as cord compression is transient and most fetuses are able to compensate for reduce umbilical blood flow. Routine antenatal ultrasound scan is not advisable, as mode of delivery and labor management does not change with detection of NC antenatally. Therefore, vaginal delivery with routine labor protocol can be allowed in cases of nuchal cord.
导致酸中毒的出生窒息占围产儿死亡的 20-60%。脐带绕颈(NC)是导致出生窒息的可能原因之一。在产前检测到有脐带绕颈的胎儿中,大多数能够成功进行阴道分娩。本研究旨在分析阴道分娩中脐带绕颈对胎儿酸碱状态和围产儿结局的影响。
根据有无 NC、单圈和多圈,将 150 名阴道分娩产妇均等分为三组。分析脐动脉血液的生化标志物,即 pH 值、PO2、SPO2、PCO2、HCO3(-)、标准碱剩余和乳酸,以评估酸中毒。比较产时并发症,如异常胎心监护、胎粪污染羊水、第二产程延长、产道器械助产、第三产程并发症。在新生儿中,比较各组间出生体重、5 分钟时 Apgar 评分≤7、NICU 入院及住院期间其他发病率和死亡率,采用合适的统计学检验。比较紧圈和松圈的上述参数。
NC 组的产时并发症发生率明显高于无 NC 组,尤其是紧圈。NC 新生儿胎粪污染羊水、5 分钟时 Apgar 评分≤7、生化标志物异常、NICU 转科的发生率明显更高。然而,新生儿的 pH 值均未处于酸中毒范围,且大多数新生儿在健康状态下出院。
NC 产妇可能会顺利分娩,因为脐带受压是短暂的,大多数胎儿能够代偿减少的脐血流。常规产前超声检查并不适宜,因为即使在产前检测到 NC,分娩方式和产时管理也不会改变。因此,在 NC 情况下可以允许阴道分娩,并按照常规产时方案进行管理。