RISK OF PRETERM DELIVERY IN PREGNANT-WOMEN WITH GROUP-B STREPTOCOCCALURINARY INFECTIONS OR URINARY ANTIBODIES TO GROUP-B STREPTOCOCCAL ANDESCHERICHIA-COLI ANTIGENS

Objective To establish whether there is an association between preterm delivery and either group B streptococcal urinary infection or the pr esence of urinary antibodies to group B streptococcal or E. coil antig ens. Design A prospective study with urine culture and antibody measur ement performed at the first antenatal visit and at 28 weeks gestation . Setting Ninewells Hospital, Dundee. Subjects Two thousand and forty- three women registering consecutively at an antenatal clinic. Main out come measure Delivery at less than 37 weeks gestation. Results No incr ease in preterm delivery was observed in women with positive urine cul tures for group B streptococci either at booking or at 28 weeks, even when confirmed by positive repeat cultures. Preterm delivery was more common in women with elevated urinary antibodies to E. coil antigens a t booking (relative risk 1.81, 95% CI 1.22-2.68, P = 0.005) and at 28 weeks (relative risk 2.36, 95% CI 1.60-3.48, P < 0.0001) and to group B streptococcal antigens at 28 weeks (relative risk 2.24, 95% CI 1.46- 3.43, P = 0.0003). Conclusions These data do not support previous repo rts that positive urine cultures for group B streptococci are associat ed with an increased risk of preterm delivery. Our report of an associ ation between elevated levels of urinary antibodies and preterm delive ry is a new finding consistent with the possibility that a local infla mmatory response to uro-genital infection may be important in stimulat ing the onset of preterm labour. The results suggest that screening fo r urinary antibodies at 28 weeks gestation might help to identify a gr oup of women at increased risk of prematurity.