Amniotic fluid prostaglandins do not reflect human fetal lung maturation

Experimental data suggest the involvement of classic prostaglandins (PG), prostacyclin (PGI2) and thromboxane A2 (TxA2) in fetal pulmonary development. To explore this possibility in man, we assayed serial amniotic fluid samples from 33 women for 13,14-dihydro-15-keto-PGF2 alpha (M-PGF2 alpha, a metabolite of PGF2 alpha), 6-keto-PGF1 alpha (a breakdown product of prostacyclin (PGI2)), and thromboxane B2 (a metabolite of TxA2) as well as for the lecithin/sphingomyelin (L/S) ratio and phosphatidylglycerol. No difference in these prostanoids was seen between the samples with the immature (less than 2) or mature (greater than or equal to 2) L/S ratio, or between the samples with undetectable or detectable phosphatidylglycerol. The L/S ratio matured in 16 women and phosphatidylglycerol became detectable in 19 women during serial sampling, but even in these women the changes in the amniotic fluid prostanoids were inconsistent. It is concluded that the amniotic fluid M-PGF2 alpha, 6-keto-PGF1 alpha and TxB2 do not reflect fetal pulmonary maturity.