Uterine tocolysis at cesarean breech delivery with epidural anesthesia

To assess the safety and efficacy of ritodrine and nitroglycerin for uterine relaxation during cesarean section with a breech-presenting fetus, performed under nongeneral anesthesia.

A retrospective review of all breech singletons delivered by cesarean section under epidural anaesthesia in a two-year period. The study groups consisted of those who received ritodrine and those who received nitroglycerin. A group who received no relaxant served as a comparison group. The interval from uterine incision to delivery was recorded, and comparisons for potential complications of the medications included maternal changes in pulse and blood pressure, blood loss, and changes in hemoglobin and hematocrit. Fetal outcomes that were evaluated included five-minute Apgar score, cord pH and any recorded birth trauma. Statistical significance was set at P = .05. The Student t test, Yates's correlation for chi 2, Fisher's exact test and ANOVA were used as appropriate.

The three groups had similar demographic characteristics. There was no significant difference in the uterine incision to delivery interval between the groups. In three cases the uterine incision to delivery interval was prolonged (> 5 minutes) in the nitroglycerin group, six cases in the ritodrine group and three in the comparison group (P = .002). There was no case of serious maternal morbidity or mortality, and no patient required a blood transfusion. The three groups had similar estimated blood loss, changes in maternal heart rate and systolic blood pressure intraoperatively and fall in hemoglobin and hematocrit 24 hours postoperatively. Neonatal outcome was similar among the three groups, and there was no case of neonatal birth trauma or intrapartum death. Cord blood analysis was similar in the three groups. One of the seven infants weighing < 1,500 g died within one hour of birth.

Ritodrine and nitroglycerine are safe agents for use at cesarean breech delivery with epidural anesthesia and may be considered for uterine relaxation when a traumatic delivery is anticipated or encountered. Our results do not support the use of these tocolytics for "routine" cesarean breech delivery.