Fetal and meternal monitoring in spontaneous labors and in elective inductions. A comparative study

SCHWARCZ, RICARDO L.; BELIZAN, JOSE M.; CIFUENTES, J.RODRIGO; CUADRO, JOSÉC.; MARQUES, MARILIA B.; CALDEYRO-BARCIA, ROBERTO

AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY

MOSBY-ELSEVIER

Año: 1974 vol. 120 p. 356 - 362

0002-9378

Fetal heart rate variations and uterine contractility were studied by continuous monitoring in 17 spontaneous labors and 17 elective inductions. The pregnancies were at term and without known complications. The incidence of type I dips was lower in spontaneous labors than in elective inductions (21 and 49 per cent, respectively, p < 0.001). The intensity of contractions was lower in spontaneous labors (X = 38 mm. Hg) than in elective inductions (X = 43 mm. Hg) (p < 0.001). In both groups the intensity of contractions and the incidence of type I dips were directly related. At a given intensity the incidence of type I dips was greater in the induced labors. The higher incidence of type I dips found in the induction group could be attributed to the greater intensity of contractions and the counter pressure on the fetal head caused by a greater resistance of the birth canal. Type I dips are caused by uneven compression and deformation of the fetal head which may cause EEG alterations, cerebral lesions, and neurological sequelae. We recommend the proscription of inductions when no important medical indications justify them. © 1974.