Low serum level of mannan-binding lectin is a determinant for pregnancy outcome in women with recurrent spontaneous abortion.

Objective: The purpose of this study was to investigate the genetic background for the previously reported finding of an increased frequency of low levels of mannan-binding lectin in couples with unexplained recurrent spontaneous abortion and to evaluate the impact of low mannan-binding lectin levels on future pregnancy outcome.

Study Designs: Mannan-binding lectin levels were measured in 217 women with unexplained recurrent spontaneous abortion and 111 of their husbands and were compared with corresponding measurements in 104 couples with uncomplicated reproductive histories and 210 blood donors. An investigation of the genetic polymorphism, which is largely responsible for serum mannan- binding lectin levels, was done by polymerase chain reaction methods with DNA from a subset of the patients and control subjects. Information was collected about the outcome of the patients' next pregnancies, together with perinatal data concerning the patients' first birth that occurred before or after being assigned to the study.

Results: Among women with recurrent spontaneous abortion, 18.9% of the women had mannan-binding lectin levels of
Conclusion: Low maternal serum mannan-binding lectin levels exhibit a negative impact on pregnancy outcome in women with unexplained recurrent spontaneous abortion.