Amniotic fluid spectrophotometry, urinary estrogen estimations, and intrauterine transfusion in severe Rh isoimmunization

Abstract

Amniotic fluid spectrophotometry, urinary estrogen levels, and intrauterine transfusion were utilized in the management of 11 severely Rh-isoimmunized pregnancies. Four infants survived. Three deaths were directly related to the transfusion procedure, and the clinical and biochemical data suggested that the remainder were moribund at the time of initial therapy. A modification of the Liley method of amniotic fluid analysis is presented in which bilirubin is reported as milligrams per cent with a semilogarithmic scale. A rapid estrogen assay, taking 6 hours, was carried out and found to relate well to bilirubin levels. The estrogen excretion curve is the only useful method for fetal assessment following intrauterine transfusion, and stable or rising levels give the clinicians confidence to carry the pregnancy closer to term. Falling levels of urinary estrogens, even if still within normal limits, indicate fetal deterioration, except immediately after transfusion when the fall may be due to fetal trauma.