The outcome of 52 pregnancies in 34 women who had had bacteriuria in childhood was compared with that of normal control pregnancies. The prevalence of bacteriuria at the first antenatal visit was significantly higher (p less than 0.001) in previously bacteriuric women (35%) than in controls (5%), and acute pyelonephritis developed in 10% compared with 4% of controls. Pre-eclampsia (arterial pressure above 140/90 mm Hg with proteinuria above ++) developed in 4 of 12 previously bacteriuric women known to have renal scarring (5 of 16 pregnancies), in only 1 of 22 previously bacteriuric women without scars (1 of 36 pregnancies), and in 1 of 52 controls (p less than 0.001). Women with renal scars were also more likely to undergo induction of labour (44% of pregnancies) and operative delivery (57% of pregnancies) than previously bacteriuric mothers without scars (17%, 22%) or control mothers (16%, 20%). The infants of previously bacteriuric mothers were not significantly smaller than those of healthy control mothers, but Apgar scores were lower among offspring of previously bacteriuric mothers with scarred or normal kidneys (p less than 0.001). Fetal outcome was, however, satisfactory in all cases.