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

Acta Obstet Gynecol Scand. 2016 Aug;95(8):926-33. doi: 10.1111/aogs.12905. Epub 2016 Apr 26.

Abstract

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.

Keywords: Interleukin-6; intra-amniotic inflammation; microbial invasion of the amniotic cavity; preterm birth; preterm prelabor rupture of membranes; short-term neonatal outcome.

MeSH terms

  • Amniotic Fluid / microbiology*
  • Apgar Score
  • Bacteria, Aerobic / isolation & purification
  • Bacteria, Anaerobic / isolation & purification
  • Chorioamnionitis / diagnosis
  • Chorioamnionitis / etiology
  • Chorioamnionitis / microbiology*
  • Female
  • Fetal Membranes, Premature Rupture / microbiology*
  • Gestational Age*
  • Humans
  • Infant, Newborn
  • Infant, Premature
  • Infant, Premature, Diseases / etiology*
  • Infant, Premature, Diseases / therapy
  • Intensive Care, Neonatal / statistics & numerical data
  • Logistic Models
  • Mycoplasma / isolation & purification
  • Pregnancy
  • Pregnancy Outcome
  • Prospective Studies
  • Ureaplasma / isolation & purification