Admission test: a screening test for fetal distress in labor.

The usefulness of a short electronic fetal heart rate recording at admission of patients in labor (admission test) was investigated in low-risk patients in two prospective studies. The admission test was done in a concealed manner, and the result of the test was evaluated after delivery so as not to influence the clinical management. In part I of the investigation, the test was performed in 130 patients monitored during labor with pH determinations in scalp blood and in cord blood at birth. Patients with reactive admission tests had a low rate of intrauterine asphyxia in labor (0.9%), whereas half of the patients with ominous traces had intrauterine fetal asphyxia with a low scalp blood pH and neonatal depression. Similar results were obtained in part II, when the admission test was used as a screening procedure involving 1041 patients. The test was reactive in 94.3%, and in this group fetal distress (cesarean section, or forceps on that indication, or an Apgar score less than 7 at five minutes) occurred in 1.3%. Ten patients (1.0%) had ominous tests; four of these had fetal distress, and one of these fetuses died in utero three hours after admission, during which time stethoscopic auscultation failed to detect the fetal compromise. It is concluded that the admission test can detect fetal distress already present at admission and unnecessary delay in intervention can be avoided in such a case. The test seems also to have some predictive value for the fetal well-being for the next few hours of labor. The test is simple and convenient for screening purposes.