Fetal and maternal bubbles detected noninvasively in sheep and goats following hyperbaric decompression.

Pregnant sheep and goats were compressed with air to an equivalent depth of 49 msw (160 fsw) for bottom times ranging from 5 to 15 min. Maternal (precordial) and fetal (umbilical artery) circulation were monitored transcutaneously with a Doppler ultrasound flowmeter to determine the presence of decompression gas bubbles. It was found that the number of bubbles detected precordially in the maternal circulation exceeded the number detected in the fetal umbilical artery for any given bottom line. Additionally, bubbles were found in the fetal circulation even when the mother did not display signs of decompression sickness. Thus, avoidance of symptoms of pain-only decompression sickness in the mother is not sufficient to preclude gas phase formation in the fetus.