Health: Warning over birthing pools

Birthing pools, in which women deliver underwater, may ease the passage from womb to world but they carry a formerly unrecognised danger to the baby. Doctors at the Chelsea and Westminster hospital, London, report a case in which a baby girl narrowly escaped permanent brain damage after being born in a pool hired by her mother at home.

The girl was born normally and the mother stayed in the pool cradling her while waiting for the afterbirth. When this had not arrived after 30 minutes, the mother got out and the midwife clamped the umbilical cord carrying the blood vessels linking the mother with the baby.

The next day the baby was floppy and not feeding properly. Hospital tests showed she had very thick blood with almost twice the normal quantity of red blood cells. Thick blood carries a danger that it may sludge in small blood vessels in the brain causing permanent damage. In this case the baby was treated to dilute her blood and made a complete recovery.

Dr Ed Abrahamson and colleagues, writing in the Lancet medical journal, say the problem was probably due to blood draining from the mother's afterbirth into the baby while they were still in the pool. In a normal birth the blood vessels in the umbilical cord constrict on exposure to the air but in a birthing pool where the water is kept at around 36Ccord blood vessels may stay open much longer.

The doctors advise mothers using birthing pools either to get out of the water or to clamp the cord within a minute or two of delivery of the baby.

- Jeremy Laurance