Is tocolysis safe in the management of third-trimester bleeding?

Expectant management is among the current treatment options for pregnancies complicated by third-trimester bleeding at <36 weeks' gestation. The use of tocolytic agents to stop associated contractions is still somewhat controversial, however, and the number of cases reported to date is small. The purpose of our study was to find a large number of cases of preterm third-trimester bleeding that was treated with tocolytic agents and evaluate them for any evidence of potential harm related to the use of these agents.

Every case of third-trimester bleeding for a 6-year period was obtained from a perinatal database that was created as patients were hospitalized. Only cases of patients with onset of bleeding between 23 and 36 weeks' gestation were analyzed. Data collected included the gestational age at the time of first bleeding, the gestational age at delivery, whether tocolytic agents were used, the need for transfusion, maternal morbidity, and neonatal outcome.

A total of 236 cases, consisting of 131 cases of abruptio placentae and 105 cases of placenta previa, met the study criteria. In the abruptio placentae group 95 women (73%) were treated with tocolytic agents. In this group the mean gestational age at the time of first bleeding was 28.9 weeks, the mean time from bleeding until delivery was 18.9 days, the median time from bleeding until delivery was 7 days, and the neonatal mortality rate was 51 deaths/1000 live births. In the placenta previa group 76 patients (72%) were treated with tocolytic agents. In this group the mean gestational age at first bleeding was 29.5 weeks, the mean time from bleeding until delivery was 29.3 days, the median time from bleeding until delivery was 22 days, and the neonatal mortality rate was 39 deaths/1000 live births. In both groups the need for transfusion and the incidence of fetal distress were not increased by the use of tocolytic agents. Among the 171 combined patients who underwent tocolysis, no maternal morbidity related to the tocolytic agents was found and no stillbirths occurred after admission. The neonatal deaths were all related to complications of prematurity.

This is the largest series to date evaluating the use of tocolytic agents in preterm patients with third-trimester bleeding. From these data there does not appear to be any increased morbidity or mortality associated with tocolytic agent use in a controlled tertiary setting. A prospective randomized trial would be necessary to determine whether tocolytic use carries any benefits.