Cardiac asystole at birth: Is hypovolemic shock the cause?

SummaryA birth involving shoulder dystocia can rapidly deteriorate—from a fetus with a reassuring tracing in the minutes before birth, to a neonate needing aggressive resuscitation. Infants experiencing a traumatic birth involving shoulder dystocia may be severely compromised, even when the preceding labor was uncomplicated. This paper presents two cases in which infants had normal heart beats recorded 5–10 min before birth and were born with cardiac asystole following shoulder dystocia. Often, in cases of shoulder dystocia, infants shift blood to the placenta due to the tight compressive squeeze of the body in the birth canal (along with cord compression) and thereby may be born hypovolemic. Our hypothesis is that the occurrence of sudden cardiac asystole at birth is due to extreme hypovolemic shock secondary to the loss of blood. At birth, the sudden release of pressure on the infant’s body results in hypoperfusion resulting in low central circulation and blood pressure. Severe hypovolemic shock from these effects leads to sudden cardiac arrest. Immediate cord clamping maintains the hypovolemic state by preventing the physiologic and readily available placental blood from returning to the infant. Loss of this blood initiates an inflammatory response leading to seizures, hypoxic-ischemic encephalopathy, and brain damage or death. Animal studies have shown that human umbilical stem cells injected into a rat’s abdomen after induced brain damage, can protect the rat’s brain from developing permanent injury. To prevent damage to newborns, the infant must receive the blood volume and stem cells lost at the time of descent and immediate cord clamping. Recommended countermeasures for research include: (1) resuscitation at the perineum with intact cord; or (2) milking the cord before clamping; or (3) autologous transfusion of placenta blood after the birth; or (4) rapid transfusion of O negative blood after birth and before seizures begin.