Blood Contaminated Amniotic Fluid and the Lamellar Body Count Fetal Lung Maturity Test.

OBJECTIVE

To determine if maternal blood contamination falsely elevates the lamellar body count fetal lung maturity test.

STUDY

DESIGN

Fifty mothers undergoing amniocentesis for fetal lung maturity consented to participation in the study. For each participant a blood-contaminated sample using the patient's own blood was run in tandem with the noncontaminated sample used for clinical practice.

RESULTS

Of the 50 study patient samples the lamellar body count decreased by ≥ 3,000/μL in 33 (66%) and remained unchanged in 16 (32%). In only 1 case did the value increase--the actual result of 37,000/μL increased to 44,000/μL, both of which exceeded the mature level in our institution.

CONCLUSION

Maternal blood contamination of amniotic fluid does not falsely increase the lamellar body count in 98% of cases. The result was falsely lowered in 2 out of 3 cases. Therefore, a mature lamellar body count test result in a blood-contaminated sample is reliable