Chemical Changes in Amniotic Fluid

The scope of my talk as represented by its title encompasses a very large field which time does not allow me to cover in its entirety. Therefore, I will limit my remarks to one very specific area where chemical changes in amniotic fluid could be used to predict fetal maturity. An ever present dilemma in modern obstetrical management is the proper timing of delivery of the fetus in situations where complications either threaten its own life in utero or significantly affect maternal morbidity. In such situations the obstetrician is confronted with the equivocal choice between premature delivery and the high risk to the fetus of continued intrauterine existence. In addition, he is placed in a unique position where any sort of direct communication with one of his "patients," namely the fetus, is nearly impossible. In the past, the delivery of obstetrical care to the fetus and the monitoring of its well-being were possible only through the agency of the maternal organism. To improve upon this situation, methods had to be found that would give a more direct and accurate reflection of fetal status. Hence, as complete a collection as possible of accurate indices relating to fetal maturity is of great importance to the obstetrician. Some of the notable complications of pregnancy in which these indices would be of value are diabetes, toxemia, erythroblastosis fetalis, and previous poor obstetrical history: for example, cases requiring repeat cesarean sections or abruptio placentae. In the late fifties (Jeffccate and Scott, 1959), it was recognized that the fetus contributed metabolic products and secretions to the amniotic fluid, and this encouraged many researchers to investigate a possible correlation between the status of the fetus and the amniotic fluid constituents. At that time, however, the technique for amniocentesis had not been