2ND-TRIMESTER AMNIOTIC-FLUID OR MATERNAL SERUM INTERLEUKIN-10 LEVELS AND SMALL-FOR-GESTATIONAL-AGE NEONATES

Objective: To evaluate if interleukin-10 levels in either early second -trimester amniotic fluid ((AF) Or. maternal serum Can be utilized as a predictor of the subsequent occurrence of small for gestational age (SGA) infants after controlling for gestational age at delivery. Metho ds: We identified patients who underwent genetic amniocentesis for sta ndard genetic indications or maternal blood sampling for maternal seru m alpha-fetoprotein (MSAFP)/triple screen between January 1992 and Feb ruary 1995 with available follow-up delivery data. Small for gestation al age was defined as birth weight less than the tenth percentile for gestational age. Control patients were matched for gestational age at delivery, maternal age, race, and parity with at least two controls fo r each study patient. We excluded patients with maternal immune diseas e, chronic hypertension, diabetes, asthma, congenital heart disease, m ultiple gestation, and fetuses with structural or chromosomal anomalie s. Second-trimester AF and serum samples were assayed for interleukin- 10. Potential confounding variables considered were MSAFP level, smoki ng history, pregnancy-induced hypertension, and neonatal gender. The i nterleukin-10 levers were normalized using natural log transformation for statistical analysis. Statistical analysis included chi(2), Fisher exact test, and analysis of variance, with P < .05 considered signifi cant. Results: From the AF data base, 18 patients (6%) delivered SGA n eonates and were matched with 46 controls, From the maternal serum dat a base, 13 patients (7%) delivered SGA neonates and were matched with 45 controls. Neither AF nor maternal serum interleukin-10 levels were significantly different in patients subsequently delivering SGA neonat es compared with controls (AF: median 21.0 pg/mL, [range 13.8-27.6] ve rsus 17.5 pg/mL [range 8.9-362.12], P = .18; serum: median 15.7 pg/mL [range 9.9-73.5] versus 18.7 pg/mL [range 9.7-71.7], P = .60, respecti vely). No significant differences were identified in gestational age a t sampling, maternal smoking history, pregnancy-induced hypertension, or elevated MSAFP in patients delivering SGA neonates compared with co ntrols (P > .05 for each). As expected, birth weight was significantly lower in patients delivering SGA neonates compared with controls (P < .001). Conclusion: Second-trimester AF or maternal serum interleukin- 10 levels are not predictive of subsequent delivery of SGA infants.