Is a cause of postpartum hemorrhage of using of tocolytic agents in preterm delivery?

Objective: Tocolytic agents are used to inhibit uterine contraction in preterm. The authors undertook this study to determine whether using of tocolytic agents before delivery is associated with increase postpartum hemorrhage in preterm delivered women.

Method: 296 singleton pregnancies delivered preterm from 24 + 1 to 37 + 0 weeks gestation were retrospectively reviewed. Hemoglobin (HB) and hematocrit (HCT) levels were checked before and after delivery to access postpartum blood loss. Multivariate logistic regression analysis was performed to determine whether delivery within the half-lives of tocolytic agents was associated with decreased HB and HCT levels.

Results: After adjusting for maternal age, parity, gestational age at delivery, birth weight, delivery method, and induction of labor, postpartum HB and HCT levels of those delivered within half-lives of tocolytic agents were found to be significantly diminished (HB: OR 3.306, 1.308-8.356 95% CI, p = 0.011; HCT: OR 2.692, 1.077-6.726 95% CI, p = 0.034). In addition, blood transfusion rates were elevated for deliveries made within the half-lives of tocolytic agents, (p = 0.006).

Conclusions: Delivery within half-lives of tocolytic agents was found to be associated with low HB and HCT levels after delivery and higher blood transfusion rates in preterm delivered women.