Impact of microbial invasion of amniotic cavity and the type of microorganisms on short-term neonatal outcome in women with preterm labor and intact membranes.

INTRODUCTION: The objective of this study was to evaluate the impact of microbial invasion of the amniotic cavity and the type of microorganisms on pregnancy and short-term neonatal outcomes in women with preterm labor. MATERIAL AND METHODS: Prospective observational cohort study including women with preterm labor from 22.0 to 36.0 weeks. Microbial invasion of the amniotic cavity was defined based on amniotic fluid aerobic/anaerobic/mycoplasma cultures, and intra-amniotic inflammation on amniotic fluid interleukin-6 levels. Demographic data and pregnancy outcomes were compared among women exposed to microbial invasion of the amniotic cavity by Ureaplasma spp., women with microbial invasion of the amniotic cavity by other microorganisms, and a No-microbial invasion of the amniotic cavity/No-intra-amniotic inflammation group. The short-term neonatal outcome was evaluated in women delivering after 24.0 weeks. RESULTS: We included 228 women with preterm labor. Microbial invasion of the amniotic cavity occurred in 35% (80/228), 28% (22/80) being caused by Ureaplasma spp. Gestational age at admission and at delivery were significantly earlier and the rate of delivery at <24.0 weeks' gestation and of women who further developed clinical chorioamnionitis were significantly higher in women with microbial invasion of the amniotic cavity by microorganisms other than Ureaplasma spp. However, after 24 weeks, regardless of the microorganisms isolated, the short-term neonatal outcome was similar between women exposed to microbial invasion of the amniotic cavity and the No-microbial invasion of the amniotic cavity/No-intra-amniotic inflammation group when gestational age was considered. CONCLUSIONS: Microbial invasion of the amniotic cavity by microorganisms other than Ureaplasma spp. was associated with earlier gestational age at admission and at delivery, and a higher rate of preterm delivery <24.0 weeks and of women who developed clinical chorioamnionitis. However, we did not find differences in the short-term neonatal outcome between women exposed to microbial invasion of the amniotic cavity and the no-microbial invasion of the amniotic cavity/no-intra-amniotic inflammation group delivering after 24.0 weeks' gestation when adjusted by gestational age at delivery.

Gestational age is more important for short-term neonatal outcome than microbial invasion of the amniotic cavity or intra-amniotic inflammation in preterm prelabor rupture of membranes.

INTRODUCTION: The aim of this study was to evaluate, in women with preterm prelabor rupture of membranes (PPROM), the impact on short-term neonatal outcome of microbial invasion of the amniotic cavity (MIAC), intra-amniotic inflammation (IAI), and the microorganisms isolated in women with MIAC, when gestational age is taken into account. MATERIAL AND METHODS: Prospective cohort study. We included women with PPROM (22.0-34.0 weeks of gestation) with available information about MIAC, IAI and short-term neonatal outcome. MIAC was defined as positive aerobic/anaerobic/genital Mycoplasma culture in amniotic fluid. Definition of IAI was based on interleukin-6 levels in amniotic fluid. Main outcome measures were Apgar score <7 at 5 min, umbilical artery pH ≤7.0, days in the neonatal intensive care unit, and composite neonatal morbidity, including any of the following: intraventricular hemorrhage grade III-IV, respiratory distress syndrome, early-onset neonatal sepsis, periventricular leukomalacia, necrotizing enterocolitis, and fetal or neonatal death. Labor was induced after 32.0 weeks if lung maturity was confirmed; and otherwise after 34.0 weeks. RESULTS: MIAC and IAI were found in 38% (72/190) and 67% (111/165), respectively. After adjustment for gestational age at delivery, no differences in short-term neonatal outcome were found between women with either MIAC or IAI, compared with the non-infection/non-inflammation ("No-MIAC/No-IAI") group. Furthermore, short-term neonatal outcome did not differ between the MIAC caused by Ureaplasma spp. group, the MIAC caused by other microorganisms group and the "No-MIAC/No-IAI" group. CONCLUSIONS: Gestational age at delivery seems to be more important for short-term neonatal outcome than MIAC or IAI in PPROM.