Pregnant women whose job is physically demanding - or who do shift work - could face more childbirth problems, say scientists. A major study in the US showed that this heavy work was associated with premature delivery, high blood pressure and underweight babies.
Jobs which involved long periods of standing up, shift work and fatiguing work were also significantly linked with premature birth. Physically demanding work was defined as work involving repetitive lifting, load-carrying or other significant physical exertion.
The study of 230,000 working women was carried out at the University of Michigan.Dr Ellen Scheinder, who headed the research, said: "Activities that women engage in at work do affect their pregnancy outcome. In the past 40 years, the number of working women in developed countries has nearly trebled, and women are on average working longer into their pregnancies.