Acute intrapartum obstetric emergencyBMJ 2008; 337 doi: https://doi.org/10.1136/bmj.a1940 (Published 22 October 2008) Cite this as: BMJ 2008;337:a1940
All rapid responses
The picture shows no evidence of rupture of the vessels, and it is
impossible to say whether any vessels were, in fact, praevia - i.e. in
front of the presenting part. A more accurate description of what is
shown is a battledore placenta with a velamentous insertion of the cord.
Of course with that variant there may be vasa praevia, but certainly not
By the way "vasa praevia" is plural; the singular would be "vas
Competing interests: No competing interests
Hypovolaemia at birth - Endgame for some
Sadly hypovolaemia in the newborn is very often neglected and not thought of. As described in the answers to this picture quiz, the paediatrician needs to be warned that the baby may be born with hypovolaemia. Blood loss from vasa praevia is just one situation when significant hypovolaemia may occur at birth. A tight nuchal cord leads to selective occlusion of the umbilical vein and hypovolaemia in the neonate when the cord is clamped immediately at birth.(1) Another situation in which there can be sudden loss of circulating volume was recently explained by Mercer.(2) When the baby ‘s body is squeezed within the pelvis there may be a transfer of blood volume from the baby to the placenta. This is well tolerated due to the maintenance of pressure and cardiac return. However at delivery of the body, the pressure around the baby’s chest is lost, and immediately the baby’s cardiac return and output falls. This is interpreted by the attendants and paediatricians as severe hypoxic asphyxia so the cord is clamped immediately and the baby transferred to the resuscitaire. The lost blood is trapped in the placenta. Needless to say resuscitation is very difficult with a hypoxic hypovolaemic baby. The importance of the timing of cord clamping and resuscitation is being increasingly recognised.(3) Resuscitation with the cord intact is quite feasible.(4,5) Once the cord is clamped there is no easy road back. A baby who has suddenly lost 25% of its circulation volume(6) may never recover properly even if the blood loss is recognised early and the volume immediately replaced.(7,8) In the case of haemorrhage from vasa praevia the cord does need to be clamped quickly to stop further loss. However at the time of delivery the cord should be clamped as close to the placenta as possible, perhaps after milking the cord towards the baby. With a long length of cord there is the opportunity for the paediatrician to “transfuse” the baby with the volume of blood within the cord. The volume can be significant. There is no high grade evidence base to support this action, which, like the recommended management by the authors for vasa praevia, is based on rational thinking. There is however high grade evidence to show that immediate cord clamping in otherwise healthy births results in harm.(9,10) In some of these babies, immediate cord clamping may be the start of their endgame! Replacing the lost stem cells is showing promising results in mitigating the damage caused by immediate cord clamping.(11)
1. Al-Tarkait A, Ogueh O, Benjamin A, Vallerand D and Usher R H. Tight nuchal cord loops (TNCL), Acute fetal blood loss and condition at birth. Paediatr Res (2002) abstracts 51;366A
2. Mercer J Potential effects of immediate cord clamping at birth. Seminar “Hypovolaemia and resuscitation – is the timing of cord clamping relevant? Royal Hospital for Sick Children, Glasgow 5th June 2008
3. The role of resuscitation drugs and placental transfusion in the delivery room management of newborn infants . Seminars in Fetal and Neonatal Medicine , Volume 13 , Issue 6 , Pages 416 - 423 J . Wyllie , S . Niermeyer
4. Hutchon DJR, Thakur I. Br Congress Obstet Gynaecol. London 2007 Resuscitation with the placental circulation intact
5. Hutchon DJR, Thakur I. Resuscitate with the placental circulation intact. Arch Dis Child 2008;93:451.
6. Niermeyer S. Volume resuscitation: crystalloid versus colloid. Clinics in Perinataology (2006) 33:133-140
7. Rajnik M et al Early cytokine expression induced by haemorrhagic shock in a non-resuscitated rat model. Paediatr Res 2001 49 44A
8. Nelson K R et al Neonatal cytokines and coagulation factors in children with cerebral palsy. Ann Neurol 1998 44 665
9. Rabe H, Reynolds G, Diaz-Rossello J. Early versus delayed umbilical cord clamping in preterm infants. Cochrane Database Syst Rev 2004;(4):CD003248.
10. Mercer et al Delayed cord clamping in very preterm infants reduces the incidence of intraventricular haemorrhage and late onset sepsis: a randomised controlled trial Pediatrics 2006
11. Cord Blood for Neonatal Hypoxic-Ischemic Encephalopathy This is a pilot study to test feasibility of collection, preparation and infusion of a baby's own (autologous) umbilical cord blood if the baby is born with signs of brain injury. NCT00593242
Competing interests: No competing interests