Characterisation of nausea and vomiting in early pregnancy: a survey of 1000 women

SummaryA one year population survey of 1000 women has been performed to determine the onset, occurrence and severity of pregnancy sickness and to correlate this information with a variety of biological markers in order to help explain the aetiology of this side effect of pregnancy. Of the women, 85 per cent experienced nausea and 52 per cent vomiting. Of these, 70 and 40 per cent reported daily nausea and vomiting respectively. Only 17 per cent of women who had nausea reported that their symptoms occurred exclusively in the morning, the corresponding proportion for vomiting being 31 per cent. In a third of the women the onset of pregnancy sickness occurred within four weeks of the last period and in three quarters, within six weeks; furthermore the earlier the onset of symptoms the more likely women were to suffer from frequent bouts of nausea and vomiting. Positive correlations were found with the occurrence of pregnancy sickness and age, parity and the development of food cravings. The occurrence of premenstrual symptoms, migraine and travel sickness were also positively correlated with the incidence of pregnancy sickness.