Elevation of amniotic fluid macrophage colony-stimulating factor in normotensive pregnancies that delivered small-for-gestational-age infants.

PROBLEM: Macrophage colony-stimulating factor (M-CSF) promotes placental growth and maintenance. We evaluated whether amniotic fluid M-CSF levels were altered in normotensive pregnancies that produced small-for-gestational-age (SGA) infants arising from unknown factors.

METHOD OF STUDY: This study enrolled 68 Japanese women experiencing normotensive pregnancies with single fetuses. Of these pregnancies, 22 delivered SGA infants arising from unknown factors (SGA group); one delivered an SGA infant with intestinal obstruction. The other 45 were women who delivered appropriate-for-gestational-age (AGA) infants (AGA group). They were selected as controls. Amniotic fluid was collected and the M-CSF levels were compared between the two groups. The M-CSF level was determined by enzyme-linked immunosorbent assay method.

RESULTS

Amniotic fluid M-CSF concentrations were 6525 pg/mL (median) in the SGA group and 4790 pg/mL in the AGA group; the concentrations were significantly higher in the SGA group than in the AGA group. The M-CSF concentrations in the woman who delivered an SGA infant with intestinal obstruction showed very high values (24290 pg/mL).

CONCLUSION

We demonstrated a significant increase in amniotic fluid M-CSF levels in the SGA group. Excessive concentrations of M-CSF in amniotic fluid via amniotic membranes may be highly related to immunological abnormalities contributing to low birth weight of neonates.