[Plasma estriol in the surveillance of the second half of pregnancy. Report of 227 cases].

The authors have attempted to devise a simple technique based in exclusively chemical methods to assay plasma estriol. The results obtained have shown the lack of fiability of such a method, in spite of fairly good correlation with urine estriol levels. Only methods utilizing labelled estrogen or radiomyological techniques can yield fiable results in the assay of plasma estriol.