MIDTRIMESTER AMNIOTIC-FLUID TUMOR-NECROSIS-FACTOR-ALPHA DOES NOT PREDICT SMALL-FOR-GESTATIONAL-AGE INFANTS

PROBLEM: To evaluate the independent ability of midtrimester amniotic fluid tumor necrosis factor-alpha (TNF-alpha) in the prediction of sma ll-for-gestational-age (SGA) infants. METHOD OF STUDY: In this case-co ntrol study, patients delivering a SGA infant were matched with contro ls based on GA at delivery, maternal age, race, and parity. Patients w ith immune disease, chronic hypertension, diabetes, asthma, congenital hearts disease, multiple gestation, and fetal anomalies were excluded . Amniotic fluid samples were immunoassayed for TNF-alpha. Potential c onfounding variables evaluated were maternal serum alpha-fetoprotein l evel, smoking history, pregnancy induced hypertension, and neonatal ge nder. Statistical analysis included Fisher's exact test and ANOVA afte r log transformation with P < 0.05 considered significant. RESULTS: Ei ghteen patients delivered SGA neonates and were matched with 41 contro ls. No significant differences were identified in the confounding vari ables between patients with SGA neonates and controls. Amniotic fluid TNF-alpha levels were not significantly different between patients sub sequently delivering SGA neonates and controls [median 7.63 (range 0.2 5-16.1) pg/mL versus 9.39 (0.25-66.9) pg/mL, P = 0.8]. CONCLUSIONS: Mi dtrimester amniotic fluid TNF-alpha levels are not predictive of SGA n eonates when compared with controls matched for gestational age at del ivery.