Inflammatory cytokines and antioxidants in midtrimester amniotic fluid: correlation with pregnancy outcome.
OBJECTIVE
Elevated interleukin-6 (IL-6) level in midtrimester amniotic fluid is associated with preterm delivery. We hypothesized that, in patients with elevated IL-6, vitamin C and alpha-fetoprotein may provide protection from spontaneous preterm delivery through antioxidant functions.


METHODS
Antioxidant potential of alpha-fetoprotein was assessed in vitro. Amniotic fluid was collected from a prospective cohort of patients who underwent midtrimester amniocentesis. In patients with IL-6 >600 pg/mL, alpha-fetoprotein, vitamin C, tumor necrosis factor-alpha, tumor necrosis factor receptors, and antioxidant capacity were compared between subjects with spontaneous preterm and term deliveries.


RESULTS
Alpha-fetoprotein demonstrated 75% the antioxidant capacity of albumin in vitro. Of 388 subjects, 73 women had elevated IL-6 levels. Among these subjects, alpha-fetoprotein, but not vitamin C, was significantly lower in 9 women with preterm birth. Antioxidant capacity correlated with vitamin C and tumor necrosis factor receptors, but not with alpha-fetoprotein or pregnancy outcome.


CONCLUSIONS
Amniotic fluid alpha-fetoprotein, but not vitamin C, may protect against preterm birth in patients with elevated midtrimester IL-6 levels.
Pressman
Eva K
EK
Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.
Thornburg
Loralei L
LL
Glantz
J Christopher
JC
Earhart
Angela
A
Wall
Peter D
PD
Ashraf
Mufeed
M
Pryhuber
Gloria S
GS
Woods
James R
JR
D000649:Amniocentesis; D000653:Amniotic Fluid / Q000737:chemistry / Q000378:metabolism*; D001205:Ascorbic Acid / Q000032:analysis / Q000378:metabolism*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D015850:Interleukin-6 / Q000032:analysis / Q000378:metabolism*; D016014:Linear Models; D011247:Pregnancy; D011256:Pregnancy Outcome; D011262:Pregnancy Trimester, Second / Q000378:metabolism*; D000509:alpha-Fetoproteins / Q000032:analysis / Q000378:metabolism*
D015850:Interleukin-6; D000509:alpha-Fetoproteins; D001205:Ascorbic Acid