Dr Jean Golding will tell a conference on smoking and pregnancy, organised by the Health Education Authority, that woman whose mothers smoked are more likely to miscarry and have troubled pregnancies.
Such women are 29 per cent more likely to miscarry than women whose mothers did not smoke during the pregnancy. They are also more likely to have started their periods earlier and to have had more problems with their first pregnancy, including bleeding.
'These are very preliminary findings but they are quite dramatic. It does seem to indicate that smoking may be doing something to the sex hormones,' Dr Golding, professor of paediatric and perinatal epidemiology at the university's Institute of Child Health, said.
The research also found that the sons of mothers who smoked in pregnancy were more likely to have 'slight abnormalities', particularly undescended testes.
Dr Golding said: 'It is quite feasible that a mother smoking during pregnancy is more likely to have an imbalance of her sex hormones, resulting in a disturbance in the way in which the reproductive organs of her own daughter evolve with long-term consequences on the success of the daughter's pregnancies.'
One in three mothers continues to smoke during her pregnancy. The Government aims to reduce that figure by at least one-third by 2000. 'It is important that smoking mothers are aware of these findings,' she said.
The results are part of an on-going study of 14,893 women in Avon who were pregnant in 1991 and 1992. The women were questioned about their mothers' experiences when they were carrying them. Dr Golding said the first generation of mothers who smoked had more problems in mid-pregnancy - 'more vomiting, more susceptibility to urinary infection and more bleeding'.