Mannan-binding lectin concentration during normal human pregnancy.

Relative deficiency of mannan-binding lectin (MBL) is associated with recurrent miscarriage. To investigate whether MBL concentration alters as a result of pregnancy, serial measurements were made in 14 patients before and during normal early pregnancy. Additionally, a longitudinal study was made of one individual over several years and including two normal pregnancies. Three (20%) subjects experienced a significant increase in MBL concentration during pregnancy. It was concluded that a modest but significant increase in MBL concentration can result from pregnancy, but it is a rare occurrence in the first trimester.