RIVIERA MAYA, MEXICO — All babies born by vacuum extraction should have an umbilical cord hematocrit drawn, and be closely monitored for changes that could signify a subgaleal bleed—an unusual injury in these deliveries, but the most devastating one possible, Dr. Michael G. Ross said at a conference on obstetrics, gynecology, perinatal medicine, neonatology, and the law.
“I suggest that all vacuum deliveries have an umbilical cord hematocrit. … It's easy, it's inexpensive and it gives you a benchmark as to where this baby started, so that if it starts behaving abnormally you can easily see what's happening [with regard to bleeding],” said Dr. Ross, chairman of obstetrics and gynecology at the University of California, Los Angeles.
Intensive monitoring in the first few hours after birth, including noting blood pressure, heart rate, and cephalic swelling, can also help identify these babies, who can easily lose half their blood volume into the subgaleal space before being diagnosed.
All too often, these devastating bleeds escape notice until the baby is in serious danger. “Pediatricians are usually first concerned about anoxia, so they ventilate the baby, and then infection, so they give antibiotics. The initial hematocrit that's drawn in the nursery may come back as 45%, which can be read as a low normal, but which in reality may already be showing a loss of one-third of the baby's blood volume.” The umbilical hematocrit provides a true baseline for the baby's red blood cells; a significant neonatal blood loss may be detected by decreasing hematocrit, greatly increasing the likelihood of catching a potentially fatal bleed, he said.
A subgaleal hemorrhage is a large collection of blood in the soft tissue space between the galea aponeurotica and the skull's periosteum. Unlike a cephalohematoma, this bleed crosses suture lines. The space in which it occurs can hold up to 250 cc of blood—equal to a baby's entire blood volume.
Most physicians first became aware of this complication after a 1998 FDA advisory described it in 12 unsolicited deaths and nine serious injuries after vacuum deliveries. After the FDA advisory, which asked physicians and hospitals to report vacuum-related neonatal injuries, 55 injuries came to light in just 6 months; 23 of these were subgaleal hemorrhages.
The American College of Obstetricians and Gynecologists has estimated the incidence as up to 4.5% in vacuum births, though this figure is greater than that of life-threatening subgaleal bleeds, which is likely closer to 1 in 1000 vacuum births. “We do feel that it is vastly, vastly under reported,” said Dr. Ross, “The reported cases are probably just the tip of the iceberg.”
Babies with this type of bleed usually begin acting abnormally about 1 hour after birth. The swelling on the head is soft to firm, fluctuant, and diffuse. In minor bleeds, the baby may be pale and show anemia. In major bleeds, there can be hypotonia, hypotension, seizures, and permanent brain injury.
Aside from restoring blood volume and administering coagulation factors and vitamin K, the best method of treatment remains unknown, Dr. Ross said. Surgery, drains, and wrapping the head have all been proposed, but there are no good data to support any of these options.
There are no firmly established risk factors for subgaleal bleeds. Preexisting hypoxia or coagulopathy have been proposed, but most proposals focus on vacuum extraction technique: difficult extraction, prolonged vacuum use, incorrect cup placement, rocking motions during extraction, and incorrect direction of traction.
“There are no good data to suggest that any of these factors really cause it, though,” Dr. Ross said at the meeting sponsored by Boston University. “I have seen many cases [in legal settings] where there was one pull in the normal direction and the baby came right out, and there was a subgaleal bleed. Nevertheless the liability is such that we have to have good indications for a vacuum delivery and use the right methods, have the right number of pop-offs and the correct duration, because you will be held responsible for it if you don't follow the rules.”
Attorney commentators at the meeting concurred that defending such cases is “extraordinarily difficult.”
“It's almost as if the burden of proof is on the defendant to prove that there was an indication for the delivery and it was done correctly,” said Brian McKeen, a plaintiff's attorney from Northville, Mich.
John Scully, a defendant's attorney from Dallas, Texas, agreed. “These are exceptionally difficult cases to defend in a courtroom. They evoke enormous sympathy from a juror. The defendant must walk a fine line by demonstrating that he did everything possible to deliver the baby safely and did it intensely and according to the standards of care, yet still persuade the jury that he did not use excessive force while doing it. And that can be a tough sell,” he said.