Study suggests possible clue to miscarriage

Low concentrations in early pregnancy of a protein involved in the immune system could be a potential indicator for miscarriage, suggest authors of a research letter in a January 2004 issue of The Lancet. According to the research, around 10 to 15 percent of pregnancies result in miscarriage, with no treatment available to prevent fetal loss and no biological markers to identify women at high risk. Macrophage inhibitory cytokine 1 (MIC 1) plays an important part in the immune system and is found in high concentrations at the interface between mother and fetus during pregnancy.

Stephen Tong and colleagues from Monash University, Melbourne, and University of New South Wales, Sydney, Australia, investigated whether MIC1 plays a part in maintaining pregnancy viability by comparison of concentrations between failed and successful pregnancies.

The investigators found that MIC1 concentrations were around a third lower among 100 women who went on to miscarry than 200 women who delivered normally (the control group). MIC1 concentrations were measured in blood taken in the first trimester of pregnancy (6 to 13 weeks). There was no difference in reduced MIC1 concentrations in relation to the timing of miscarriage, although in most cases low MIC1 concentrations preceded miscarriage by several weeks.

"If a causal link between low MIC1 and miscarriage is confirmed, then MIC1, or its synthetic analogues, might be useful in prevention of miscarriage," Tong says.