Amniotic Fluid Lamellar Body Count for Prediction of Foetal Lung Maturity

Abstract

Predicting maturity of the foetal lung is extremely important in many obstetric situations as respiratory distress syndrome caused by surfactant deficiency remains one of the leading causes of neonatal morbidity and mortality. The need for predicting the foetal lung maturity by means of an accurate test which is done rapidly and available in majority of centres was the objective for this study. AIM To find out the optimum lamellar body count which correlates with foetal lung maturity and to compare the lamellar body count with shake bubble test. MATERIAL AND METHODS This prospective study was designed to evaluate the lamellar body count by standard haematology cell counter that is coulter counter and compare it with shake bubble test. Both the tests were done on 100 amniotic fluid samples in women with gestational age more than 28 weeks. Patients recruited were those who were sure of their last menstrual period (LMP), who were in active labour, and likely to deliver within 72 hours of collection of sample. Amniotic fluid samples obtained by transabdominal amniocentesis or by aspirating the forewaters per vaginum. Both shake bubble test and lamellar body count were done on the sample. RESULTS Lamellar body counts ranged from 10,000-2,43,000/microlitre and had a linear relationship with gestational age. The cutoff level of 30,000/microlitre was considered to be optimum to predict foetal lung maturity. Sensitivity and negative predictive value of lamellar body count at 30,000/microlitre and shake bubble test were comparable at 91.7%/91.7% and 97.3/96.6% respectively whereas with respect to specificity and positive predictive value, lamellar body count was superior to shake bubble test at 93.4%/73.7% and 81.5%/50%. CONCLUSION Lamellar body count is a rapid, inexpensive, simple and more reliable test to assess foetal lung maturity.