Amniotic fluid phosphatidylglycerol: a potentially useful predictor of intrauterine growth retardation

Intrauterine growth retardation, a major complication of pregnancy, remains difficult to detect reliability prior to birth. In this retrospective study of 82 pregnancies which resulted in birth of small infants, preceding clinical factors and amniotic fluid (AF) maturity tests were examined for their ability to differentiate small for gestational age (SGA) from appropriate for gestational age (AGA) infants of comparable weight. AF maturity tests included phosphatidylglycerol (PG), phosphatidylinositol (PI), lecithin to sphingomyelin ratio (L/S), PG/PI, PG/S, PI/S, foam tests, and fat cell count. Discriminant analysis revealed that AF PG was potentially the most useful parameter for predicting the birth of an SGA infant. The predictive value of PG was related to the strong correlation of AF PG with term gestation. High AF PG could potentially predict SGA infants with a true positive rate of 60%; 64% of all SGA infants could be correctly identified by means of only AF PG. The results of this study suggest that, in selected high-risk pregnancies, amniocentesis late in gestation with determination of PG may be helpful in classifying small infants as either growth retarded or preterm.