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Evaluation of the effect of meconium on assessment of fetal lung maturity status by TDxFLM II testing
Todd S Albright1, David F Colombo, Elizabeth Euscher
1Department of Obstetrics and Gynecology, The Ohio State University College of Medicine and Public Health, Columbus, Ohio, USA. live2bike@comcast.net
Objective:
To evaluate the effect of meconium contamination on the TDxFLM II assay.
Methods:
Amniotic fluid was collected from patients undergoing amniocentesis for obstetric indications between 31 and 40 weeks of gestation. A baseline TDxFLM II value was obtained and compared with amniotic fluid contaminated with 1%, 5%, and 10% meconium by weight.
Results:
Twenty-one samples were studied, and in every case the TDxFLM II value decreased once the meconium was added. There was no consistent rate of decrease that correlated with the percentage of meconium added.
Conclusion:
Meconium contamination decreases the TDxFLM II value. A clinician who performs this test in the presence of meconium can be reassured that the contamination will not give an artificially elevated result. If the result is in the mature range, one can be confident that the result would only be higher if meconium were not present.
Insights
Meconium contamination lowers the TDxFLM II assay value. Clinicians can trust mature results, as meconium does not artificially elevate fetal lung maturity test readings.
Area of Science:
- Obstetrics and Gynecology
- Clinical Chemistry
- Fetal Medicine
Background:
- The TDxFLM II assay is used to assess fetal lung maturity.
- Meconium staining of amniotic fluid is a common finding during pregnancy.
- The impact of meconium on assay accuracy requires investigation.
Purpose of the Study:
- To determine how meconium contamination affects the TDxFLM II assay results.
- To assess the reliability of the TDxFLM II assay in the presence of meconium.
Main Methods:
- Amniotic fluid samples were collected from pregnant patients (31-40 weeks gestation).
- Baseline TDxFLM II values were established.
- Samples were then contaminated with 1%, 5%, and 10% meconium by weight and re-tested.
Main Results:
- Meconium contamination consistently decreased TDxFLM II values in all tested samples.
- No direct correlation was observed between the percentage of meconium and the rate of decrease in assay values.
- Twenty-one amniotic fluid samples were analyzed.
Conclusions:
- Meconium contamination leads to a decrease in TDxFLM II assay values.
- Clinicians can be assured that meconium will not cause a falsely elevated fetal lung maturity result.
- A mature result in the presence of meconium indicates true fetal lung maturity.
