Microbial invasion of the amniotic cavity in pregnancies with small-for-gestational-age fetuses.
Microbial invasion of the amniotic cavity (MIAC) has been detected in women with preterm labor, preterm prelabor rupture of membranes (PROM), and in patients at term with PROM or in spontaneous labor. Intrauterine infection is recognized as a potential cause of fetal growth restriction; yet, the frequency of MIAC in pregnancies with small-for-gestational-age (SGA) fetuses is unknown. The aim of this study was to determine the frequency, diversity and relative abundance of microbes in amniotic fluid (AF) of women with an SGA neonate using a combination of culture and molecular methods.



AF from 52 subjects with an SGA neonate was analyzed with both cultivation and molecular methods in a retrospective cohort study. Broad-range and group-specific PCR assays targeted small subunit rDNA, or other gene sequences, from bacteria, fungi and archaea. Results of microbiologic studies were correlated with indices of the host inflammatory response.



1) All AF samples (n=52) were negative for microorganisms based on cultivation techniques, whereas 6% (3/52) were positive based on PCR; and 2) intra-amniotic inflammation was detected in one of the three patients with a positive PCR result, as compared with three patients (6.1%) of the 49 with both a negative culture and a negative PCR (P=0.2).



MIAC is detected by PCR in some patients with an SGA fetus who were not in labor at the time of AF collection.
DiGiulio
Daniel B
DB
Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA.
Gervasi
Maria Teresa
MT
Romero
Roberto
R
Vaisbuch
Edi
E
Mazaki-Tovi
Shali
S
Kusanovic
Juan Pedro
JP
Seok
Kimberley S
KS
Gómez
Ricardo
R
Mittal
Pooja
P
Gotsch
Francesca
F
Chaiworapongsa
Tinnakorn
T
Oyarzún
Enrique
E
Kim
Chong Jai
CJ
Relman
David A
DA
D000328:Adult; D000650:Amnion / Q000382:microbiology*; D000653:Amniotic Fluid / Q000382:microbiology; D001483:Base Sequence; D002821:Chorioamnionitis / Q000382:microbiology; D015331:Cohort Studies; D017931:DNA Primers / Q000235:genetics; D019641:DNA, Archaeal / Q000235:genetics / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D004271:DNA, Fungal / Q000235:genetics / Q000302:isolation & purification; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D008828:Microbiological Techniques; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000382:microbiology*; D011256:Pregnancy Outcome; D012189:Retrospective Studies; D055815:Young Adult
D017931:DNA Primers; D019641:DNA, Archaeal; D004269:DNA, Bacterial; D004271:DNA, Fungal