Women attending a twin pregnancy antenatal clinic underwent cervical palpation to calculate a cervical score by subtracting dilatation from length. Those with a score of -2 or less at or before 34 weeks are at especially high risk of preterm labour. A total of 139 such women were randomly allocated either to receive bed-rest in hospital or to continue conventional outpatient management. No beneficial effect of bed-rest could be identified in prolonging twin pregnancy or improving fetal outcome.