S. Vroman

Intravenous prostaglandin F2α and amniotomy for the elective induction of labor at term

In an earlier trial [7, 11] with intravenously administered PGF2# for the elective induction of multiparae at term, amniotomy was delayed to comply with FD A regulations. As a consequence, the Start of the electronic supervision was also postponed and thus the refined assessment of the potential fetal ha2ards of PGF2& was prevented. The present study was tailored in accordance with the dual purpose of meeting our primary objective (to study the effects of PGF2# in the fetus and the newborn) by relying on a procedure actually used in clinical obstetrics, i. e. amniotomy followed by the intravenous infusion of an oxytocic drug.

A double blind comparative study of prostaglandin F2α and oxytocin for the elective induction of labor

Abstract Under monitoring control, term labor was induced electively in two groups of 25 women each, in one by an intravenous infusion of prostaglandin (PG) F 2α and in the other with an intravenous infusion of synthetic oxytocin (Pitocin ® ), according to a fixed dosage schedule. At birth, both the clinical and the biochemical state of the fetuses were evaluated. It is concluded that in the dosage used, PGF 2α is without adverse effects on the mother. Labor could be effectively induced with both PGF 2α and oxytocin. If hyperstimulation of the myometrium is avoided during the infusion, the fetal condition is not endangered by either of these compounds. It is, however, our impression that PGF 2α leads more easily to uterine hyperstimulation than does Pitocin ® . For this reason the clinical use of PGF 2α should be probably confined to well-equiped obstetrical units.

The value of fetal monitoring for the prediction of the biochemical and clinical status of the infant at birth. The “monitor-normal” case

Abstract The authors have sought an answer to the question: is it possible to predict the condition — clinical and biochemical — of the fetus at birth solely by continuous monitoring of the fetal heart rate (FHR) and the intrauterine pressure during the greater part of the first stage of labor and during the entire second stage? This report of the first part of their study is restricted to the statistical analysis of 88 “ monitor-normal ” cases characterized (a) by normal FHR and contractility patterns throughout labor and (b) by a smooth second stage. For the estimation of the fetal oxygen debt, a specific biochemical parameter was used, i.e. the fetal-maternal difference in excess lactate . The conclusion is reached that “ monitor-normal ” cases show a normal biochemical state of the infant at birth. The relationship between the physical parameters (FHR and intra-amniotic pressure) and the clinical state at birth (Apgar score), on the other hand, was found to be significantly less accurate.

Elective induction of labor conducted under lumbar epidural block: II. Labor induction by amniotomy and intravenous prostaglandin☆

Labor was electively induced at term in 117 clinically normal nulliparae and parous women by combining low amniotomy with intravenous administration of prostaglandin F2 alpha (n = 64) or prostaglandin E2 (n = 53). Analgesia was obtained by continuous lumbar epidural block with bupivacaine. The procedure was very effective in producing vaginal delivery within 24 h after prostaglandin infusion (n = 115), but it was accompanied by an extremely high incidence of uterine hypertonus. Tentative explanations for the transient uterine hyperstimulation are a direct stimulatory effect of the local anesthetic on the contractility of the myometrial fiber and/or a temporarily higher amount of circulating oxytocic compound reaching the myometrium due to local vasodilatation as a result of sympathetic nerve blockade. In some cases uterine hypertonus was associated with slowing of the basal fetal heart rate and, when severe, with the appearance of late deceleration patterns and fetal acidosis. In other cases the fetal heart rate deceleration is explained by the toxic effect of bupivacaine on the myocard. Since both the myometrial hyperactivity and the FHR alterations were temporary, fetal biochemical parameters were unaffected at completion of the first stage of labor. Because with intravenous prostaglandin uterine hyperstimulation is more difficult to avoid and regional analgesia further increases the hazard of both hypertonus and fetal heart rate deceleration, the combined application of an intravenous prostaglandin and continuous epidural analgesia should not be introduced into obstetrical practice.

Elective induction of labor conducted under lumbar epidural block

Abstract Labor was electively induced at term in 117 clinically normal nulliparae and parous women by combining low amniotomy with intravenous administration of prostaglandin F 2α (n = 64) or prostaglandin E 2 (n = 53). Analgesia was obtained by continuous lumbar epidural block with bupivacaine. The procedure was very effective in producing vaginal delivery within 24 h after prostaglandin infusion (n = 115), but it was accompanied by an extremely high incidence of uterine hypertonus. Tentative explanations for the transient uterine hyperstimulation are a direct stimulatory effect of the local anesthetic on the contractility of the myometrial fiber and/or a temporarily higher amount of circulating oxytocic compound reaching the myometrium due to local vasodilatation as a result of sympathetic nerve blockade. In some cases uterine hypertonus was associated with slowing of the basal fetal heart rate and, when severe, with the appearance of late deceleration patterns and fetal acidosis. In other cases the fetal heart rate deceleration is explained by the toxic effect of bupivacaine on the myocard. Since both the myometrial hyperactivity and the FHR alterations were temporary, fetal biochemical parameters were unaffected at completion of the first stage of labor. Because with intravenous prostaglandins uterine hyperstimulation is more difficult to avoid and regional analgesia further increases the hazard of both hypertonus and fetal heart rate deceleration, the combined application of an intravenous prostaglandin and continuous epidural analgesia should not be introduced into obstetrical practice.

Fetal effects of prostaglandins

25 women were electively induced at term by means of an intravenous infusion of (PGF2alpha) prostaglandin F2alpha administered according to a fixed schedule. 90 minutes after the start of the infusion the membranes were ruptured and the fetus was monitored until the time of delivery. Only 2 cases showed uterine hypertonus 1 with and 1 without fetal bradycardia. Both fetuses were clinically and biochemically normal at the time of birth. At birth the mean lactate-pyruvate parameters were not statistically different in PG babies and normal controls. The mean values of the conventional parameters of the acid-base equilibrium (umbilical artery blood) showed a statistically significant difference from the control group. However all but 3 individual values were still within the limits of biochemical normality. (Authors modified)

The influence of deaminooxytocin on uterine contractility and the fetus in normal term pregnancy

Abstract Buccal tablets of deaminooxytocin were used to induce (28 women) or to augment labor (130 women). 95 patients were excluded from the study on the basis of other than pharmacological possible influences. Monitoring of intrauterine pressure and fetal heart rate was done in 59 cases. There was a decrease of the mean base excess in the induction group under clinical supervision (P Two cases of fetal acidosis for which the fractional administration of oxytocin may be held responsible, stress the necessity of monitoring the hazards of administration of oxytocic drugs.