Bleeding in brain common at birth

A quarter of babies born vaginally suffer small hemorrhages in their brains, perhaps from compression of the head during delivery, according to researchers who performed the first high-resolution magnetic resonance imaging studies on healthy newborns.

The bleeding heals quickly and most likely does not produce long-term effects, the team reported Monday in the online version of the journal Radiology.

"After all, women have been delivering vaginally for millions of years," said Dr. Honor Wolfe of the University of North Carolina School of Medicine, one of the authors of the report. No bleeding was observed during Caesarean deliveries, but the authors cautioned that this should not be taken as an argument to support C-sections.

"At this point, neither parents nor providers should change their plans for delivery," Wolfe said.

An earlier British study had found similar bleeding in 10 percent of newborn infants, but those studies were conducted somewhat longer after birth using a less-sensitive imager.

The Carolina researchers studied 88 newborns, an average of three weeks after birth. Seventeen of the 65 who underwent vaginal delivery suffered small hemorrhages in the brain but none of the 23 who had C-sections.

"Neither the size of the baby or the baby's head, the length of the labor, nor the use of vacuum or forceps to assist the delivery caused the bleeds," said Dr. John Gilmore of UNC, the lead author.

"It's just the process of being born," he said. The skull has not yet become solid, and the bone plates overlap. Passage through the birth canal compresses the plates, tearing small blood vessels, he said.

But, he added, "there was no evidence clinically to indicate that anything had happened to the babies' brains." The team will examine the babies again at ages 1 and 2 to look for possible long-term effects.

Dr. J. Keith Smith, a UNC radiologist, noted that radiologists are increasingly using MRI to examine newborns and are likely to observe similar hemorrhages.

"The reassuring thing is that this is ... not an indication of pathology," he said.