Tocolysis in farm animal reproduction.

Tocolysis is an obstetrical procedure carried out with the use of medicines for delaying the parturition presenting preterm contractions. Various tocolytics have been studied with the objective of stopping preterm labor, increasing gestational age at parturition and preventing complications related to preterm birth. Preterm parturition accounts for about 70% of neonatal calf deaths. Commonly used tocolytic medications include ß2 agonists, calcium channel blockers, NSAIDs, oxytocin and prostaglandin antagonistic and magnesium sulfate. These can assist in delaying preterm delivery by suppressing uterine muscle contractions and their use is intended to reduce fetal morbidity and mortality associated with preterm birth. The tocolytic medicated animal must be kept under intensive observation because of its adverse effects on cardiovascular system and other complications. The suppression of contractions is often only partial and tocolytics can only be relied to delay birth for a few days. Further research and professional guidelines are needed on optimal use of these agents. This review aims to summarize the major classes of tocolytics, their effects and review the evidence regarding use of each. [ABSTRACT FROM AUTHOR]