Predictive value of amniotic fluid and fetal blood cultures in pregnancy outcome in preterm prelabour rupture of membranes.

We carried out a comprehensive prospective study of 26 pregnancies complicated by preterm rupture of the membranes. Microbiological assessment included cultures for aerobic and anaerobic bacteria, Mycoplasmas, Chlamydia, Trichomonas and fungi from: high vaginal and cervical swabs, maternal blood and urine, amniotic fluid and fetal blood on admission and finally, placenta and umbilical cord = after delivery. The group with positive cultures (n 16), was compared with the group with negative cultures = (n 10) in terms of gestational age at labour, latent phase after membrane rupture and fetal and neonatal morbidity and mortality. All patients with positive cultures delivered before 32 weeks and their neonates had evidence of infection. Three intrauterine deaths occurred in this group and 12/13 (86%) of the live neonates were admitted to the neonatal intensive care unit. The 10 (38%) patients of the group with negative cultures delivered after 32 weeks, had no perinatal deaths, and only two were admitted to neonatal intensive care. The median latent phase differed between these two groups (4.5 vs. 53.5 days, P 0.01), as did the median gestational age at labour (28 vs. 36 4 weeks, P 0.01). A positive amniotic fluid or fetal blood culture in the clinical setting of preterm rupture of the membranes indicates labour onset within a few days. Intrauterine infection with fetal sepsis is accompanied by high neonatal infectious morbidity (100%) and mortality (30%).