早产是指自末次月经第一日起妊妊满28周至37周前终止者,是围产儿死亡的重要原因之一,仅次于先天畸形,占第二位,早产的发生率多数报道在5—10％左右。 早产治疗中抑制宫缩是重要的一项手段。宫缩抑制剂主要分两类:一类为抑制宫缩减少了子宫肌对刺激反应的药物,一类为阻断或抑制前列腺素(PG)合成的药物。早产的治疗均是通过抑制宫缩使子宫呈松弛状态,或使子宫肌对外来刺激反应性降低,从而减低子宫肌的收缩强度和频率,避免早产发生。 Preterm birth refers to the first menstruation since the first day of pregnancy from 28 weeks to 37 weeks before termination of pregnancy, is one of the important causes of perinatal death, second only to congenital malformations, accounting for the second most prevalent in the incidence reported in 5 -10% or so. Inhibition of contractions during preterm labor is an important means. There are two main types of tocolytic agents: one is a drug that suppresses uterine muscle responses to stimuli to suppress uterine contractions, and one is drugs that block or inhibit prostaglandin (PG) synthesis. Treatment of prematurity is by inhibiting uterine contractions to a relaxed state, or to reduce the uterine muscle stimulation to reduce reactivity, thereby reducing the contractility and frequency of uterine muscle, to avoid premature birth.