Amniocentesis in the management of preterm premature rupture of the membranes.

A retrospective analysis has been performed of perinatal outcome in 81 pregnancies in which preterm premature rupture of membranes (PPROM) was managed using amniocentesis to diagnose intrauterine infection and lung maturity. Ten patients (13%) had a positive Gram stain on microscopy whilst 29 (37%) had a positive culture. Forty-one patients (58%) had a mature lecithin:sphingomyelin ratio. There was evidence of sepsis in 13 neonates (16%), with a further 16 (20%) being colonized. Both Gram stain and amniotic fluid culture were relatively poor predictors of neonatal sepsis. For Gram stain the sensitivity was low at only 15%. Although the sensitivity for culture was higher (69%), the specificity (71%) was too low to be clinically useful. It is recommended that a randomized controlled trial of amniocentesis in PPROM is needed to define the role of this diagnostic test.