When shoulder dystocia takes five or more minutes to resolve, the neonate is likely to be depressed and need vigorous resuscitation [
The fetal heart rate tracing had been normal. The second stage lasted less than 1 hour. The head delivered with maternal effort alone and a loop of cord was passed over the baby’s neck. Shoulder dystocia was resolved with a combination of McRoberts’ maneuver, suprapubic pressure, Rubin’s maneuver, and Woods’ corkscrew maneuver. The elapsed time from delivery of the head to delivery of the baby was 4.5 minutes.
The cord was immediately clamped and the baby handed to the waiting neonatal team. There was no heart rate or respiratory effort. Resuscitation included positive-pressure ventilation, chest compressions, intubation, and epinephrine. Volume resuscitation began at 25 minutes of age, and the heart rate became detectable after 120 mL of normal saline had been infused.
The birth weight was 4.4 kilograms. The umbilical cord artery pH was 7.16 and the venous pH was 7.27. Following resuscitation, the arterial pH was 6.76. The baby had severe encephalopathy, and brain MRI showed damage to the deep gray structures and brainstem. Care was withdrawn after 1 week of life.
Labor was induced because of insulin-treated diabetes. There was no concern about the fetal heart rate tracing. The head was delivered by vacuum after three pulls. A nuchal cord was swept over the head. Shoulder dystocia was resolved by McRoberts’ positioning, suprapubic pressure, and delivery of the posterior arm. The head-to-body interval was 4 minutes.
The cord was immediately clamped and the neonatology team took over. There were no spontaneous respirations. Positive-pressure ventilation was initiated and intubation was performed for ongoing ventilation. A heartbeat was not audible, and chest compressions were started within the first minute of birth. Ventilation, chest compressions, and epinephrine were continued. At 11 minutes of age, a 60 mL bolus of normal saline was pushed through an umbilical venous catheter. The heartbeat became audible within 1 minute. Another 45 mL of normal saline was administered between 25 and 48 minutes of age.
The birth weight was 4.3 kilograms. The umbilical cord artery pH was 7.05 and the umbilical venous pH was 7.14.
The heart rate was over 100, but the baby remained flaccid with no spontaneous movements, other than spontaneous respirations. Perfusion was poor. Arterial pH at 1 hour of age was 6.92 with a lactate of 20. There was no spontaneous movement, no response to stimuli, and no reflexes. The arterial gases continued to deteriorate, and the baby died at 2.5 hours of age.
In both of these cases, the fetal heart rate tracings had not shown fetal compromise before the occurrence of the shoulder dystocia. In each case, the shoulder dystocia was resolved in less than 5 minutes. The babies were resuscitated by neonatologists according to the Neonatal Resuscitation Program guidelines. But the babies still died.
This has been described before. In the UK review [
In animal experiments [
One possible explanation for the different outcome in shoulder dystocia was proposed a few years ago [
For the obstetrician who has successfully resolved a severe shoulder dystocia, with all its attendant stress and anxiety, the natural response, as soon as the baby is delivered, is to immediately clamp the umbilical cord and hand the baby over to the waiting neonatal resuscitation team. This is the actual recommendation of the Society of Obstetricians and Gynaecologists of Canada, “if the fetus is depressed, then the baby should be handed over for immediate resuscitation… [
If the hypothesis of hypovolemic shock is correct, then a change may be needed in the neonatal resuscitation protocols. Current neonatal resuscitation guidelines [ “Volume expanders should not be routinely given during resuscitation in the absence of a history or indirect evidence of acute blood loss. Giving a large volume load to a baby whose myocardial function is already compromised by hypoxia can decrease cardiac output and further compromise the newborn…” “Indications for volume expansion during resuscitation include: (i) Baby is not responding to resuscitation. AND (ii) Baby appears in shock (pale color, weak pulses, persistently low heart rate, no improvement in circulatory status despite resuscitation efforts). OR (iii) There is a history of a condition associated with fetal blood loss (e.g.: extensive vaginal bleeding, placenta previa, twin-to-twin transfusion, etc.).”
The neonatal resuscitation algorithm comprises assessment and initial steps; positive-pressure ventilation; positive-pressure ventilation and chest compressions; positive-pressure ventilation, chest compressions, and epinephrine and endotracheal intubation; and, finally, umbilical venous catheterization for volume replacement if there has not been a good response to the aforementioned steps. All this generally means that at least 10 minutes will elapse before any volume will be given. And then the suggested volume to be given, 10 mL/kg of saline over 5 to 10 minutes, will probably be inadequate if the fetus has lost a significant amount of blood.
Of course, the hypothesis that some babies who have been delivered after shoulder dystocia are in hypovolemic shock is still a hypothesis (the article was indeed published in a journal called Medical Hypotheses), but the circumstances of our two cases lend support to this hypothesis. In the first case, there was no detectable heartbeat until volume resuscitation was begun at 25 minutes of age and 120 mL of normal saline was infused. In the second case, when there was still no detectable heart rate after 11 minutes of standard resuscitation, 60 mL of normal saline was pushed through an umbilical venous catheter and a heart rate was detectable within a minute afterwards. In both cases, however, it was too late.
What are the implications for management of severe shoulder dystocia?
For the obstetrician, once the shoulder dystocia has been resolved and the baby is delivered, it would be to restrain the urge to immediately clamp the umbilical cord but, instead, keep the baby between the mother’s legs for a minute or so, to let the baby be autotransfused from the placenta, and have the neonatal resuscitation team come and do the initial resuscitation steps at the mother’s bed. Alternatively, the umbilical cord can be milked with some benefit [
For the neonatal resuscitators, it would be to consider volume expansion much earlier in the resuscitation algorithm and put in an umbilical venous catheter and give volume sooner if there is no detectable heartbeat after 1 or 2 minutes. If the placenta has been delivered, one could consider taking blood from the vessels on the fetal surface of the placenta and using that to transfuse the baby with its own blood (which would also contain many stem cells that could assist the baby to repair any damage).
Dr. Carol Schneider is the coauthor of the paper.
The authors declare that there is no conflict of interests regarding the publication of this paper.