Maternal serum interferon gamma as a predictor of poor pregnancy outcome

OBJECTIVE: Cell mediated immunity via the elaboration of cytokines is involved in placentation and is thought to play an important role in pregnancy maintenance. Nearly two thirds of cases of poor pregnancy outcome are associated with abnormal placentation. ln-vitro and animal studies have shown that T-helper 1-type cytokines such as Interferon gamma (IFN y) have a detrimental effect on embryo development and pregnancy continuation. We tested the hypothesis that elevated levels of maternal serum (MS) IFN y during the early second trimester predict poor pregnncy outcome (delivery at 34 weeks' gestation or of a small-for-gestational age (SGA) infant with birth weight <IOth centile). STUDY DESIGN: A case-control study was designed inclusive of singleton gestations with I) maternal serum drawn between 14 and 22 weeks; 2) no evidence of fetal structural or chromosomal anomalies; and 3) outcome information available. Controls were matched based on maternal age, race, and parity. MS IFN y levels in cases with gestational age at delivery 34 weeks (PTD group, nl?) or delivered of a SGA infant (n = 8) were compared with those of controls delivering at >37 weeks (n=49) or of an appropriate for gestational age infant (n = 61), respectively. IFN y was measured by immunoassay (R&D Systems). Statistical analysis employed correlation and one-way ANOVA after log transformation. RESULTS: Mean ±standard deviation IFN y levels were not significantly different between PTD cases and controls (3.2 ±2.0 pg/ml vs 8.2 i 15.9 pg/ml, p=0.19), or between SGA cases and controls (2.6 ±1.2 pg/n\l vs 7.1 ±14.4 pg/ml, p=0.23). No significant correlation was present between MS IFN-y levels and gestational age at delivery. CONCLUSION: Early second trimester MS IFN γ levels are not different in pregnancies destined to deliver at <34 weeks or of a SGA infant when compared with controls.