Continued … Delivering a male was also apparently more painful. Nearly 70 per cent of women with a son needed an epidural, versus 66 per cent of those having a daughter.

Blood had to be taken from the foetus during labour - a procedure used when it is suspected a baby is in distress - in 19.5 per cent of the boys compared with 16.5 per cent of girls.

Girls scored ahead of boys on only one complication measure. The fluid surrounding them in the uterus was more likely to be stained with meconium from their gut, another indication that a baby's condition may be deteriorating because of the stress of its birth.

Boys' heads were known to be bigger on average than girls', said obstetrician Dr Eogan, which might explain the extra operative deliveries. But head size would not explain the other differences.

To avoid bias in the results, she had considered only healthy, liveborn first babies in the head-first position, whose mothers went spontaneously into labour. Records of all births at the hospital fitting those criteria between 1997 and 2000 were included in the research, which the British Medical Journal published yesterday.

[Julie Robotham, January 18 2003. This is another of those troublesome pre-blog-days articles I’ve kept only because they were interesting. It might have been BBC News – I can’t say for certain. Sorry. 2003 does not appear any too recent either but on this issue, I hope you’d agree that freshness is not all that relevant.]